JP2013056859A - π-CONJUGATED ORGANIC BORON COMPOUND AND METHOD OF PRODUCING THE SAME - Google Patents

Abstract

PROBLEM TO BE SOLVED: To synthesize a new organic boron compound that hardly has a tetra-coordination structure by subjecting a portion around boron to firm planar immobilization.SOLUTION: A specific compound is introduced into a specific boron compound, and then Friedel-Crafts reaction is made, thereby subjecting the portion around the boron to the firm planar immobilization to obtain the stable organic boron compound.

Description

  The present invention relates to a π-conjugated organoboron compound and a method for producing the same.

  The development of a π-conjugated skeleton having a characteristic electronic structure and structural characteristics has become increasingly important due to the possibility of application to organic electronic materials such as organic EL, organic thin film transistors, and solar cells. Therefore, development of a new π-conjugated skeleton having an excellent function has been actively conducted.

By the way, boron, which is a group 13 element, is an electron-deficient element because it has one less valence electron than carbon. Further, since boron has an empty _pz orbit, it has a strong π electron accepting property. For this reason, it is expected that by incorporating boron into the π-conjugated skeleton, a π-conjugated organic compound having properties that could not be achieved with carbon alone is expected.

However, organoboron compounds are generally unstable because they are susceptible to nucleophilic attack on empty _pz orbitals, and how to stabilize them in order to apply them as functional materials. Key to molecular design. On the other hand, a technique of preventing the approach of the nucleophile by sterically protecting around boron and stabilizing it kinetically is currently used. For example, the following formula:

In the trimesitylborane represented by the formula, the mesityl group is twisted into a propeller type due to repulsion between methyl groups, and the periphery of boron is sterically protected (Non-patent Document 1). For this reason, trimesitylborane is stable to air, water, and the like.

  In addition to this, many boron compounds are stabilized by incorporating boron into the π-conjugated skeleton itself and introducing a bulky substituent on the boron.

Olmstead, M. M .; Power, P. P. J. Am. Chem. Soc. 1986, 108, 4235. Tomioka, H .; Hirai, K .; Ishihara, Y .; Hu, Y. Bull. Chem. Soc. Jpn. 2001, 74, 2207. Kinzel, T .; Zhang, Y .; Buchwald, S. L. J. Am. Chem. Soc. 2010, 132, 14073. G. M. Sheldric, SHELX-97, Program for the Refinement of Crystal Structures; Universityof Gottingen: Gottingen, Germany, 1997. A. L. Spek. PLATON, A MultipurposeCrystallographic Tool, Utrecht, The Netherlands, 2005 P. van der Sluis, A. L. Spek. Acta Crystallogr. Sect. A, 1990, 46. 194.

  Thus, in order to stabilize the organoboron compound, it is common to introduce a bulky substituent on the boron. It is considered essential to introduce at least one bulky substituent on the boron. However, when a bulky substituent is introduced onto boron, all three substituents cannot be utilized in the π-conjugated system. In addition, such an organic boron compound has a problem that intermolecular interaction is inhibited in a solid state.

  From this point of view, the present invention makes it difficult to form a four-coordinate structure by solidly fixing the periphery of boron in place of the conventional method of three-dimensionally protecting the periphery of boron to prevent the nucleophile from approaching. This led to the idea of a new molecular design guideline that would reduce the reactivity with nucleophiles. The object is to synthesize such a new organoboron compound.

  As a result of intensive studies in view of the above problems, the present inventors have introduced a specific compound into a specific organoboron compound, and then caused a Friedel-Crafts reaction to firmly fix the boron around the plane. It was found that a stabilized organic boron compound was obtained. The present invention has been completed as a result of further research based on such knowledge. That is, this invention includes the invention which concerns on the following items 1-12.

  Item 1. Formula (A):

[Wherein, R ^{A1 to} R ^A4 are the same or different and R ^A1 and R ^A4 are each independently a hydrogen atom, and R ^A2 and R ^A3 are each a 1-alkylethenyl group having ³ to 22 carbon atoms. R ^A1 and R ^A2 , R ^A3 and R ^A4 may be bonded to each other to form a 6-membered heterocycle having a boron atom; R ^{A5 to} R ^A6 may be the same or different and each is a hydrogen atom alone Or an alkyl group having 1 to 20 carbon atoms, and R ^A5 and R ^A6 may be combined to form an oxo group. ]
A unit having three reaction points represented by formula (B):

[In the formula, R ^{B1 to} R ^B8 are the same or different, and R ^B1 , R ^B4 , R ^B5 and R ^B8 are each independently a hydrogen atom, R ^B2 , R ^B3 , R ^B6 and R ^B7 are 3 to 3 carbon atoms. 22 1-alkylethenyl groups, R ^B1 and R ^B2 , R ^B3 and R ^B4 , R ^B5 and R ^B6 , R ^B7 and R ^B8 are bonded to each other and have a 6-membered ring having a boron atom Heterocycle may be formed]
A π-conjugated organoboron compound having at least one unit selected from the group consisting of units having two reaction points represented by:

  Item 2. The unit represented by the general formula (A) is represented by the general formula (A1):

[Wherein, R ^{A7 to} R ^A10 are the same or different and each is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; R ^{A11 to} R ^A12 are the same or different and are each independently a hydrogen atom or 1 to 20 carbon atoms] R ^A11 and R ^A12 may be combined to form an oxo group. ]
Item 2. The π-conjugated organoboron compound according to Item 1, which is a unit having three reaction points represented by:

  Item 3. The unit represented by the general formula (B) is represented by the general formula (B1):

[Wherein, R ^{B9 to} R ^B16 are the same or different and are each a hydrogen atom or an alkyl group having 1 to 20 carbon atoms]
Item 3. The π-conjugated organoboron compound according to Item 1 or 2, which is a unit having two reaction points represented by:

  Item 4. Item 1 to 3 having 1 to 3 at least one selected from the group consisting of a unit having 3 reaction points represented by the general formula (A) and a unit having 2 reaction points represented by the general formula (B) The π-conjugated organoboron compound according to any one of the above.

  Item 5. General formula (A1a):

[Wherein, R ^{A7 to} R ^A10 are the same or different and each is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; R ^{A11 to} R ^A12 are the same or different and are each independently a hydrogen atom or 1 to 20 carbon atoms] R ^A11 and R ^A12 may be combined to form an oxo group; R ^{A13 to} R ^A15 may be the same or different and each may be a hydrogen atom, a halogen atom, a boronic acid or The ester group, silyl group or stannyl group. ]
Or general formula (B1a):

[Wherein, R ^{B9 to} R ^B16 are the same or different and each is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; R ^{B17 to} R ^B18 are the same or different and each represents a hydrogen atom, a halogen atom, a boronic acid, or its An ester group, a silyl group or a stannyl group. ]
The π-conjugated organoboron compound according to any one of Items 1 to 4, which is represented by:

  Item 6. The π-conjugated organoboron compound according to any one of Items 1 to 5, further comprising a group having a π bond.

  Item 7. The group having a π bond is a group having a thiophene skeleton, a group having a fluorene skeleton, a group having a thiazole skeleton, a group having a pyridine skeleton, a group having an oxadiazole skeleton, a group having a thiadiazole skeleton, or a benzothiadiazole skeleton Item 7. The π-conjugated organoboron compound according to Item 6, which is at least one selected from the group consisting of a group having an arylene group, an arylene group, and a triarylamine.

  Item 8. General formula (C1):

[Wherein R ^{C1 to} R ^C12 are the same or different and each is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; R ^{C13 to} R ^C16 are the same or different and each represents a hydrogen atom, a halogen atom, a boronic acid, or Ester group, silyl group or stannyl group; Y is a group having a π bond. ]
Item 8. The π-conjugated organoboron compound according to any one of Items 1, 2, and 4 to 7.

  Item 9. General formula (A1):

[Wherein, R ^{A7 to} R ^A10 are the same or different and each is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; R ^{A11 to} R ^A12 are the same or different and are each independently a hydrogen atom or 1 to 20 carbon atoms] R ^A11 and R ^A12 may be combined to form an oxo group. ]
A method for producing a π-conjugated organoboron compound having a unit having three reaction points represented by general formula (A2a):

[Wherein, R ^{A11 to} R ^A12 are the same or different and are the same as above; R ^{A13 to} R ^A15 are the same or different and are each a hydrogen atom, a halogen atom, a boronic acid or an ester group thereof, a silyl group or a stannyl group; R ^{A17 to} R ^A18 are the same or different and are each an alkyl group having 1 to 20 carbon atoms. ]
The manufacturing method provided with the process of making a Lewis acid catalyst act on the compound shown by these.

  Item 10. General formula (B1):

[Wherein, R ^{B9 to} R ^B16 are the same or different and each represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. ]
A method for producing a π-conjugated organoboron compound having a unit having two reaction points represented by:
General formula (B2a):

[Wherein, R ^{B17 to} R ^B18 are the same or different, and each represents a hydrogen atom, a halogen atom, a boronic acid or an ester group thereof, a silyl group, or a stannyl group; R ^{B19 to} R ^B22 are the same or different and each has 1 carbon atom. ˜20 alkyl groups. ]
The manufacturing method provided with the process of making a Lewis acid catalyst act on the compound shown by these.

  Item 11. Item 11. The production method according to Item 9 or 10, wherein the Lewis acid catalyst is scandium (III) trifluoromethanesulfonate.

  Item 12. General formula (C1):

[Wherein R ^{C1 to} R ^C12 are the same or different, and each represents a hydrogen atom and an alkyl group having 1 to 20 carbon atoms; R ^{C13 to} R ^C16 are the same or different, and each represents a hydrogen atom, a halogen atom, a boronic acid, or Ester group, silyl group or stannyl group; Y is a group having a π bond. ]
A method for producing a π-conjugated organoboron compound represented by
General formula (A1a-1):

[Wherein, R ^{A7 to} R ^A12 are the same or different and each represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; R ^A16 represents a halogen atom, a boronic acid or an ester group thereof, a silyl group, or a stannyl group. ]
The manufacturing method provided with the process of coupling-reacting the (pi) conjugated organoboron compound shown by these, and an organometallic compound.

  According to the present invention, it is possible to obtain an organoboron compound that is stabilized by solidly fixing the surface of boron around the surface. This compound exhibits high chemical stability and has high electron transporting ability and light emitting performance. Further, by introducing a group having a π bond into the compound, the π-conjugated system can be easily expanded, and a more stable compound can be obtained.

It is the ultraviolet visible Kyushu spectrum and fluorescence spectrum of the compound obtained in Example 3 and Comparative Example 1 in THF. 3 is an X-ray crystal structure (thermal vibration ellipsoid with an existence probability of 50%) of the reference compound obtained in Comparative Example 1. It is the X-ray crystal structure (thermal vibration ellipsoid with an existence probability of 50%) of the plane-fixed borane-substituted thiophene obtained in Example 3. 3 is a crystal structure of a plane-fixed borane-substituted thiophene obtained in Example 3. For clarity, hydrogen atoms are not shown. Here, (a) is a space filling model of the packing structure, and (b) is an enlarged view of a void surrounded by three molecules. The plane-fixed borane-substituted thiophene obtained in Example 3, the Kohn-Sham plot of the reference compound obtained in Comparative Example 1, and the energy levels of HOMO and LUMO (B3LYP / 6-31G (d) // B3LYP / 6 -31G (d)). It is the X-ray crystal structure (thermal vibration ellipsoid with 50% existence probability) of the plane-fixed triphenylborane derivative obtained in Example 7 by thermal vibration ellipsoid drawing software (ORTEP). The length (Å) and angle (°) of each bond are B1-C1 1.519 (2), B1-C9 1.520 (3), C1-C2 1.414 (2), C1-C6 1.410 (2), C9- C10 1.411 (2), C2-C7 1.537 (2), C6-C13 1.539 (2), C10-C13 1.542 (2), C1-B1-C1 * 119.8 (2), C1-B1-C9 120.1 (1) , C1 * -B1-C9 120.1 (1). X-ray crystal structure of plane 9,10-diphenyl-9,10-dihydro-9,10-diboraanthracene obtained in Example 5 (thermal vibration with 50% existence probability) by thermal vibration ellipsoid drawing software (ORTEP) Ellipsoid). The length (Å) and angle (°) of each bond are B1-C7 1.522 (3), B1-C2 * 1.530 (3), B1-C1 1.531 (3), C1-C6 1.396 (3), C1 -C2 1.428 (3), C2-C3 1.395 (3), C7-C8 1.416 (3), C7-C12 1.417 (3), C7-B1-C1 118.9 (2), C7-B1-C2 * 118.8 (2 ), C2 * -B1-C1 122.3 (2). 4 is a cyclic voltammetry of a plane-fixed triphenylborane derivative obtained in Example 7 and a plane 9,10-diphenyl-9,10-dihydro-9,10-diboraanthracene obtained in Example 5. FIG. Measurement conditions: THF (1 mM), supporting electrolyte ^{_{n-Bu 4 N + PF 6}} - (0.1 M), swept rate 100 mV s ^-1

1. π-conjugated organoboron compound The π-conjugated organoboron compound of the present invention has the general formula (A):

[Wherein, R ^{A1 to} R ^A4 are the same or different and R ^A1 and R ^A4 are each independently a hydrogen atom, and R ^A2 and R ^A3 are each a 1-alkylethenyl group having ³ to 22 carbon atoms. R ^A1 and R ^A2 , R ^A3 and R ^A4 may be bonded to each other to form a 6-membered heterocycle having a boron atom; R ^{A5 to} R ^A6 may be the same or different and each is a hydrogen atom alone Or an alkyl group having 1 to 20 carbon atoms, and R ^A5 and R ^A6 may be combined to form an oxo group (═O). ]
A unit (A) having three reaction points represented by the general formula (B):

[In the formula, R ^{B1 to} R ^B8 are the same or different, and R ^B1 , R ^B4 , R ^B5 and R ^B8 are each independently a hydrogen atom, R ^B2 , R ^B3 , R ^B6 and R ^B7 are 3 to 3 carbon atoms. 22 1-alkylethenyl groups, R ^B1 and R ^B2 , R ^B3 and R ^B4 , R ^B5 and R ^B6 , R ^B7 and R ^B8 are bonded to each other and have a 6-membered ring having a boron atom Heterocycle may be formed]
A unit (B) having two reaction points represented by
1 or more (preferably 1 to 3) of at least one unit selected from the group consisting of:

  In this specification, for convenience, the term “reaction point” is used, but in each general formula, three or two bonds are directly bonded to a non-reactive atom or group such as a hydrogen atom. Also good.

In the general formula (A), when R ^{A1 to} R ^A4 are present alone, R ^A1 and R ^A4 are hydrogen atoms, and R ^A2 and R ^A3 are 1-alkylethenyl groups having ³ to 22 carbon atoms. . Specific examples of the 1-alkylethenyl group include 1-methylethenyl group, 1-ethylethenyl group, 1-propylethenyl group (preferably 1-methylethenyl group) and the like. In this case, R ^A2 and R ^A3 may be the same or different. R ^A1 and R ^A2 , R ^A3 and R ^A4 may be bonded to each other to form a 6-membered heterocycle having a boron atom.

R ^{A5 to} R ^A6 each independently represent a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, preferably a hydrogen atom or a methyl group. In this case, R ^A5 and R ^A6 may be the same or different. R ^{A5 to} R ^A6 may together form an oxo group (═O).

  As the unit (A) having such three reaction points, the general formula (A1):

[Wherein, R ^{A7 to} R ^A10 are the same or different and each is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; R ^{A11 to} R ^A12 are the same or different and are each independently a hydrogen atom or 1 to 20 carbon atoms] R ^A11 and R ^A12 may be combined to form an oxo group (═O). ]
A unit (A1) having three reaction points represented by formula (A2):

[Wherein, R ^{A11 to} R ^A12 are the same or different and the same as above; R ^{A17 to} R ^A18 are the same or different and each represents an alkyl group having 1 to 20 carbon atoms. ]
And a unit having 3 reaction points.

In General Formula (A1), R ^{A7 to} R ^A10 are each a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, preferably a hydrogen atom or a methyl group.

In General Formula (A1), when R ^{A11 to} R ^A12 are present alone, they are each a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, preferably a hydrogen atom or a methyl group. In this case, R ^A11 and R ^A12 may be the same or different. R ^A11 and R ^A12 may together form an oxo group (═O).

  As the unit (A1) having such three reaction points, specifically,

Etc.

In the general formula (A2), R ^{A11 to} R ^A12 are the same as those in the general formula (A1).

In General Formula (A2), R ^{A17 to} R ^A18 are each an alkyl group having 1 to 20 carbon atoms, and preferably a methyl group.

  As such a unit (A2) having three reaction points, specifically,

Etc.

  As a typical example of the π-conjugated organoboron compound of the present invention having a unit (A) having three reaction points that satisfies such conditions, the general formula (A1a):

[Wherein, R ^{A7 to} R ^A12 are the same or different and the same as above; R ^{A13 to} R ^A15 are the same or different and each represents a hydrogen atom, a halogen atom, a boronic acid or an ester group thereof, a silyl group, or a stannyl group. is there. ]
Or a compound represented by the general formula (A2a):

[Wherein, R ^{A11 to} R ^A15 and R ^{A17 to} R ^A18 are the same or different and the same as above. ]
(A2a) etc. which are shown by these.

In the general formulas (A1a) and (A2a), R ^{A7 to} R ^A12 and R ^{A17 to} R ^A18 are the same as described above. R ^{A13 to} R ^A15 are a hydrogen atom, a halogen atom, a boronic acid or an ester group thereof, a silyl group, or a stannyl group. Further, if at least one (particularly all) of R ^{A13 to} R ^A15 is a halogen atom, boronic acid or an ester group thereof, a silyl group, or a stannyl group, various crosses using organometallic compounds such as Suzuki-Miyaura coupling A group having a π bond can be easily introduced by a coupling reaction. That is, the π-conjugated system can be easily expanded. R ^{A13 to} R ^A15 may be the same or different.

  Here, as boronic acid or its ester group, the general formula (5):

[Wherein, two R ^{1 s} may be the same or different and each may be a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and two R ^1s may be bonded to each other to form a ring. May be. ]
The group shown by these is mentioned.

When R ¹ of the boronic acid or its ester group represented by the general formula (5) is present alone, it is a hydrogen atom or an alkyl group. The alkyl group has 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, and more preferably 1 to 5 carbon atoms. Two R ¹ may be the same or different. Two R ^{1 's} may be bonded to each other to form a ring together with a boron atom and an oxygen atom.

  Specific examples of the boronic acid or ester group thereof represented by the general formula (5) include, for example, the following formula:

Etc.

  Compound (A2a) is a compound that can be a production intermediate of compound (A1a).

  As the π-conjugated organoboron compound of the present invention that satisfies such conditions, specifically,

(X is a halogen atom, boronic acid or its ester group, silyl group or stannyl group)
Etc.

In the general formula (B), when R ^{B1 to} R ^B8 are present alone, R ^B1 , R ^B4 , R ^B5 and R ^B8 are hydrogen atoms, and R ^B2 , R ^B3 , R ^B6 and R ^B7 are carbon numbers. 3 to 22 1-alkylethenyl groups. Specific examples of the 1-alkylethenyl group include 1-methylethenyl group, 1-ethylethenyl group, 1-propylethenyl group (preferably 1-methylethenyl group) and the like. In this case, R ^B2 , R ^B3 , R ^B6, and R ^B7 may be the same or different. Note that R ^B1 and R ^B2 , R ^B3 and R ^B4 , R ^B5 and R ^B6 , R ^B7 and R ^B8 may be bonded to each other to form a 6-membered heterocycle having a boron atom.

  As the unit (B) having such two reaction points, the general formula (B1):

[Wherein, R ^{B9 to} R ^B16 are the same or different and each represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. ]
A unit (B1) having two reaction points represented by formula (B2):

[Wherein, R ^{B19 to} R ^B22 are the same or different and each represents an alkyl group having 1 to 20 carbon atoms. ]
And a unit having two reaction points.

In General Formula (B1), R ^{B9 to} R ^B16 are each a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, preferably a hydrogen atom or a methyl group. These may be the same or different. As such a unit (B1) having two reaction points, specifically,

Etc.

In General Formula (B2), R ^{B19 to} R ^A22 are each an alkyl group having 1 to 20 carbon atoms, and preferably a methyl group.

  As such a unit (B2) having two reaction points, specifically,

Etc.

  As a typical example of the π-conjugated organoboron compound of the present invention having a unit (B) having two reaction points that satisfies such conditions, the general formula (B1a):

[Wherein, R ^{B9 to} R ^B16 are the same or different and each is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; R ^{B17 to} R ^B18 are the same or different and each represents a hydrogen atom, a halogen atom, a boronic acid, or its An ester group, a silyl group or a stannyl group. ]
Or a compound represented by formula (B1a):

[Wherein, R ^{B17 to} R ^B22 are the same as described above. ]
(B2a) etc. which are shown by these.

In the general formulas (B1a) and (B2a), R ^{B9 to} R ^B16 and R ^{B19 to} R ^B22 are the same as described above. R ^{B17 to} R ^B18 are each a hydrogen atom, a halogen atom, a boronic acid or an ester group thereof, a silyl group, or a stannyl group. Further, when at least one (particularly all) of R ^{B17 to} R ^B18 is a halogen atom, boronic acid or an ester group thereof, a silyl group, or a stannyl group, various crosses using organometallic compounds such as Suzuki-Miyaura coupling A group having a π bond can be easily introduced by a coupling reaction. That is, the π-conjugated system can be easily expanded. Note that R ^{B17 to} R ^B18 may be the same or different.

  The compound (B2a) is a compound that can be a production intermediate of the compound (B1a).

  As the π-conjugated organoboron compound of the present invention that satisfies such conditions, specifically,

(X is a halogen atom, boronic acid or its ester group, silyl group or stannyl group)
Etc.

  Thus, in the present invention, by having at least one of the unit (A) having 3 reactive sites and the unit (B) having 2 reactive sites (particularly the unit (A1) having 3 reactive sites). And having at least one of the units (B1) having two reaction points (one or more), the surface of the boron can be firmly fixed on the plane. For this reason, since the reactivity with a nucleophile can be reduced, the (pi) conjugated organoboron compound which has higher chemical stability than before is obtained.

  Moreover, since the π-conjugated organoboron compound of the present invention incorporates boron into the skeleton and is rich in electron acceptability, it has high electron transport ability and light emitting performance. From this, compared with the conventional compound, since high electron transport ability can be maintained over a long time, it is useful for uses, such as organic EL, an organic thin-film transistor, a solar cell.

  In particular, among the above compounds, the unit (B) having 2 reaction points (especially 2 reactions) compared to the compound having the unit (A) having 3 reaction points (particularly the unit (A1) having 3 reaction points). Since the compound having the unit (B1) having a point is more difficult to be reduced, it is further excellent in chemical stability.

  In addition, for example, if a halogen atom, a boronic acid or an ester group thereof, a silyl group, or a stannyl group is included at the terminal, a group having a π bond can be easily introduced into the organoboron compound of the present invention. As a result, the π-conjugated system can be expanded, and the chemical stability can be further improved.

  As described above, the organoboron compound in which the π-conjugated system is expanded includes at least one of the unit (A) having three reaction points and the unit (B) having two reaction points, and has a π bond. The group is not particularly limited as long as it contains a group. Further, in the organoboron compound in which such a π-conjugated system is expanded, the number of units (A) having 3 reaction points and units (B) having 2 reaction points is not particularly limited, and is 1 or more (especially 1 to 3), and the number of groups having a π bond is not particularly limited, and may be 1 or more (particularly 1 to 3).

  The group having a π bond is not particularly limited. For example, a group having a thiophene skeleton (thiophene, benzothiophene, benzodithiophene, thienothiophene, dithienothiophene, etc.), a group having a fluorene skeleton (fluorene, etc.), thiazole A group having a skeleton (thiazole and the like), a group having a pyridine skeleton (such as a pyridyl group), a group having an oxadiazole skeleton (such as an oxadiazolyl group), a group having a thiadiazole skeleton (such as a thiadiazolyl group), and a benzothiadiazolyl skeleton And a group derived from a triarylamine (such as triphenylamine), a group having an arylene group (such as a phenylene group), a group having an arylene group (such as a phenylene group), and the like.

  As described above, various compounds can be used as the π-conjugated organoboron compound in which the π-conjugated system is expanded by a group having a π bond. For example, when a group having a π bond is introduced only at one position of the unit (A) having 3 reaction sites, the general formula (C1):

[Wherein R ^{C1 to} R ^C12 are the same or different, and each represents a hydrogen atom and an alkyl group having 1 to 20 carbon atoms; R ^{C13 to} R ^C16 are the same or different and each represents a hydrogen atom, a halogen atom, a boronic acid or Ester group, silyl group or stannyl group; Y is a group having a π bond. ]
And a π-conjugated organoboron compound (C1) represented by

  The organoboron compound in which the π-conjugated system is expanded is not limited to the above compound, and for example, the general formula (C2):

[Wherein, R ^{C7 to} R ^C12 and Y are the same as defined above. ]
As shown, a plurality of groups having a π bond may be introduced around the unit (A) having 3 reactive sites or the unit (B) having 2 reactive sites. Moreover, you may introduce | transduce into the group which has this (pi) bond the unit (A) which has 3 reaction points, or the unit (B) which has 2 reaction points.

  Moreover, general formula (C3):

[Wherein, R ^{C17 to} R ^C34 are the same or different and each represents a hydrogen atom and an alkyl group having 1 to 20 carbon atoms; R ^{C35 to} R ^C40 are the same or different and each represents a hydrogen atom, a halogen atom, a boronic acid, or a group thereof; Ester group, silyl group or stannyl group; Y is a group having a π bond. ]
As shown, a plurality of units (A) having 3 reactive sites or units (B) having 2 reactive sites may be introduced around a group having a π bond. Further, a group having a π bond may be further introduced into the unit (A) having three reaction points or the unit (B) having two reaction points.

2. Method for Producing π-Conjugated Organoboron Compound < Compound Having Unit (A) Having Three Reactive Points and / or Unit (B) Having Two Reactive Points>
Examples of the π-conjugated organoboron compound having a unit (A) having three reaction points according to the present invention include the following formula:

[Wherein X ¹ and X ² are the same or different, X ¹ is a halogen atom; X ² is a hydrogen atom, a halogen atom, a boronic acid or an ester group thereof, a silyl group or a stannyl group; M is Li or MgX (X Are halogen atoms); R ^{A5 to} R ^A6 and R ^{A17 to} R ^A18 are the same as described above. ]
Like the reaction shown in general formula (1):

[Wherein, X ² is a hydrogen atom, a halogen atom, a boronic acid or an ester group thereof, a silyl group or a stannyl group; M is Li or MgX (X is a halogen atom); R ^{A17 to} R ^A18 are the same as above. ]
In the compound (1) represented by
General formula (2):

[Wherein, R ^{A5 to} R ^A6 are the same as above; X ¹ is a halogen atom. ]
A step of allowing the compound (2) represented by

  The compound obtained by this reaction is the π-conjugated organoboron compound of the present invention having a unit (A) having three reaction points.

  Here, compound (2) is allowed to act on compound (1) to carry out a halogen-metal exchange reaction.

  As the compound represented by the general formula (1), known compounds may be used or synthesized. For synthesis, for example, the following formula:

Wherein, X ² and X ³ are the same or different, X ² is a hydrogen atom, a halogen atom, a boronic acid or its ester group, a silyl group, or a stannyl group; X ³ is a halogen atom; the two R ² are the same Or different, each having an alkyl group having 1 to 20 carbon atoms (particularly a methyl group); R ^{A17 to} R ^A18 are the same or different and each having an alkyl group having 1 to 20 carbon atoms (particularly a methyl group); (X is a halogen atom). ]
It can be synthesized by the following reaction route.

Step (1)

[Wherein, X ² , X ³ and R ² are the same as defined above. ]

  What is necessary is just to synthesize | combine the compound shown by General formula (1a) according to well-known literature (nonpatent literature 2).

  General formula (1a):

[Wherein, X ² and X ³ are the same as defined above. ]
And X ² and X ³ may be the same or different as described above, and X ² represents a hydrogen atom, a halogen atom, a boronic acid or an ester group thereof, a silyl group or a stannyl group, X ³ is a halogen atom. Considering step (4) described later, it is preferable that X ² has low reactivity and X ³ has high reactivity. From this viewpoint, when X ² is Br, X ³ is preferably I. Further, when X ² is Cl, X ³ is preferably Br or I. If X ² is a silyl substituent such as a trialkylsilyl group, all halogen atoms can be used as X ³ .

  In this step (1), the compound represented by the general formula (1a) is oxidized to give the general formula (1a-1):

[Wherein, X ² and X ³ are the same as defined above. ]
After making into the compound (1a-1) shown by these, what is necessary is just to raise | generate esterification reaction to a carboxyl group using alcohol.

  A normal oxidizing agent may be used for the oxidation of the compound represented by the general formula (1a). Specifically, permanganate (such as potassium permanganate) can be used.

  Other known solvents and conditions may be used.

  After the compound (1a-1) is synthesized by the above method, an esterification reaction is caused to occur on the carboxyl group using alcohols (especially methanol), and the general formula (1b):

[Wherein, X ² and X ³ are the same as above; two R ² are the same or different and each represents an alkyl group having 1 to 20 carbon atoms (particularly a methyl group). ]
The compound (1b) represented by the above may be synthesized.

  As alcohols that can be used here, methanol, ethanol, propyl alcohol and the like (particularly methanol) are preferably used. Further, the amount used is not particularly limited, and may be an excessive amount.

Furthermore, as long as compound (1b) can be obtained, other substances may be added to the reaction system. For example, in order to ensure the reaction proceeds, a carboxylic acid halide is formed with an electrophilic halogenating agent such as thionyl chloride (SOCl ₂ ), sulfuryl chloride (SO ₂ Cl ₂ ), phosphorus trichloride (PCl ₃ ), etc. It is preferable to react with alcohols.

  In this case, the amount of the electrophilic halogenating agent to be used is generally 2 to 5 mol, preferably about 2 to 3 mol, per 1 mol of compound (1a-1).

  There are no particular limitations on the conditions for the esterification reaction. The reaction time can be 1 to 24 hours, preferably 4 to 20 hours. The reaction temperature is usually carried out under reflux, and can be, for example, 20 to 200 ° C, preferably 40 to 150 ° C. The reaction atmosphere is not particularly limited. Specific examples of the reaction atmosphere include an air atmosphere and an inert gas atmosphere.

Step (2)

[Wherein, X ² , X ³ , R ² and R ^{A17 to} R ^A18 are the same as described above. ]

  In step (2), the compound (1b) obtained in step (1) is reduced with an alkylmagnesium compound and then reacted with halogen.

Examples of alkylmagnesium compounds include those represented by the formula:
R'MgX '
[Wherein, R ′ represents an alkyl group having 1 to 20 carbon atoms; X ′ represents a halogen atom. ]
The alkyl magnesium compound represented by these is mentioned.

  Examples of R ′ include a methyl group.

  X 'is preferably bromine or iodine.

  As the alkylmagnesium compound, a Grignard reagent obtained by reacting an alkyl halide and magnesium metal (Mg) in an inert solvent such as THF can be used, and a known method can be employed.

  The amount of the alkyl magnesium compound to be used is usually 4 to 20 mol, preferably about 4 to 6 mol, per 1 mol of compound (1b).

  This reaction is usually performed in a solvent. There is no restriction | limiting in particular as a solvent, What is necessary is just to employ | adopt a well-known thing.

  As conditions for this reaction, the reaction time can be 1 to 24 hours, preferably 4 to 20 hours. Although reaction temperature is normally performed under recirculation | reflux and changes with solvents, it can be 20-200 degreeC, for example, Preferably it is 40-150 degreeC. The reaction atmosphere is not particularly limited. Specific examples of the reaction atmosphere include an air atmosphere and an inert gas atmosphere. As long as the compound (1c) can be obtained, another substance may be added to the reaction system.

In this way, the compound (1b) is reduced. In the compound (1b), when either X ² or X ³ is a highly reactive halogen, it may react at the same time. From this, when either X ² or X ³ is a highly reactive halogen (for example, iodine), it is preferable to cause the same halogen (for example, iodine) to act.

Step (3)

[Wherein, X ^{2 to} X ³ and R ^{A17 to} R ^A18 are the same as described above. ]

  In step (3), dehydration reaction is caused to occur in compound (1c) obtained in step (2).

  In step (3), p-toluenesulfonic acid, concentrated sulfuric acid, hydrochloric acid or the like can be used as a dehydrating agent.

  In addition, a known solvent may be employed.

  There are no particular limitations on the conditions for this reaction. The reaction time can be 0.1 to 24 hours, preferably 0.5 to 20 hours. Although reaction temperature is normally performed under recirculation | reflux and changes with solvents, it can be 20-200 degreeC, for example, Preferably it is 40-150 degreeC. The reaction atmosphere is not particularly limited. Specific examples of the reaction atmosphere include an air atmosphere and an inert gas atmosphere. As long as the compound (1d) can be obtained, other substances may be added to the reaction system.

Step (4)

[Wherein, X ² , X ³ , R ^{A17 to} R ^A18 and M are the same as defined above. ]

In step (4), in the compound (1d) obtained in step (3), X ³ is caused to undergo a halogen-metal exchange reaction using an organolithium compound or an organomagnesium compound.

  The compound that can be used in this case is not particularly limited, and known compounds can be used. Preferably, the organic lithium compound is ethyl lithium, n-propyl lithium, isopropyl lithium, n-butyl lithium, sec-butyl lithium, tert. -Butyl lithium, pentyl lithium, hexyl lithium, cyclohexyl lithium, phenyl lithium and the like. Of these, n-butyllithium and the like are preferable.

  1-1.2 mol is preferable with respect to 1 mol of compounds (1d), and, as for the usage-amount of the said organic lithium compound or organomagnesium compound, 1-1.1 mol is more preferable.

  What is necessary is just to use a well-known thing as a compound (2).

  0.5-2 mol is preferable with respect to 1 mol of compound (1), and, as for the usage-amount of a compound (2), 0.9-1.1 mol is more preferable.

  This reaction is usually performed in a solvent. The solvent may be an aliphatic organic solvent that is an aprotic solvent or an aromatic organic solvent. Examples of the aliphatic organic solvent include pentane, hexane, cyclohexane, heptane, and the like. Examples of the aromatic organic solvent include benzene and toluene.

  There are no particular limitations on the conditions for this reaction. The reaction time can be 1 to 24 hours, preferably 4 to 20 hours. Although reaction temperature changes with solvents, it can be set as -100-200 degreeC, for example, Preferably it is 0-20 degreeC. The reaction atmosphere is not particularly limited. Specific examples of the reaction atmosphere include an air atmosphere and an inert gas atmosphere. As long as the target compound can be obtained, other substances may be added to the reaction system.

  The π-conjugated organoboron compound having a unit (B) having two reaction points of the present invention can be synthesized in the same manner as the π-conjugated organoboron compound having a unit (A) having three reaction points. For example, the following formula:

[Wherein, X ^{2 to} X ⁴ are the same or different, X ² is a hydrogen atom or a halogen atom; X ^{3 to} X ⁴ are a halogen atom; R ^{B19 to} R ^B22 are the same or different, and each have 1 to 20 carbon atoms. M is Li or MgX (X is a halogen atom). ]
As in the reaction represented by general formula (1 ′):

[Wherein, X ² , R ^{B19 to} R ^B22 and M are the same as defined above. ]
In the compound (1 ′) represented by
General formula (3):

[Wherein X ^{3 to} X ⁴ are the same or different and the same as above. ]
A step of allowing the compound (3) represented by

  Compound (1 ') may be the same as compound (1) described above. Moreover, what is necessary is just to use a well-known or commercially available compound (3).

  The amount of compound (3) to be used is preferably 0.3 to 1.5 mol, more preferably 0.45 to 0.55 mol, per 1 mol of compound (1 ').

  This reaction is usually performed in a solvent. The solvent may be an aliphatic organic solvent that is an aprotic solvent or an aromatic organic solvent. Examples of the aliphatic organic solvent include pentane, hexane, cyclohexane, heptane, and the like. Examples of the aromatic organic solvent include benzene and toluene.

  There are no particular limitations on the conditions for this reaction. The reaction time can be 1 to 24 hours, preferably 4 to 20 hours. Although reaction temperature changes with solvents, it can be set as -100-200 degreeC, for example, Preferably it is 0-20 degreeC. The reaction atmosphere is not particularly limited. Specific examples of the reaction atmosphere include an air atmosphere and an inert gas atmosphere. As long as the target compound can be obtained, other substances may be added to the reaction system.

<Compound (A1) and Compound (B1)>
In the same manner as the compound (A2a-1) for which the synthesis method has been described above, the general formula (A2a):

[Wherein, R ^{A11 to} R ^A15 and R ^{A17 to} R ^A18 are the same as defined above. ]
(A2a) can be synthesized.

  Further, this compound (A2a) is the π-conjugated organoboron compound of the present invention, but is also a general formula (A1a) which is also a π-conjugated organoboron compound of the present invention:

[Wherein, R ^{A7 to} R ^A15 are the same or different and are the same as above. ]
Can be a synthetic intermediate of the compound (A1a).

  In the same manner as the compound (B2a-1) whose synthesis method has been described above, the general formula (B2a):

[Wherein, R ^{B17 to} R ^B22 are the same as described above. ]
(B2a) can be synthesized.

  Further, this compound (B2a) is a π-conjugated organoboron compound of the present invention, but is also a general formula (B1a) which is also a π-conjugated organoboron compound of the present invention:

[Wherein, R ^{B9 to} R ^B16 are the same or different and are each a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; R ^{B17 to} R ^B18 are the same or different and each represents a hydrogen atom, a halogen atom, or a boronic acid. Or its ester group, a silyl group, or a stannyl group. ]
It can be a synthetic intermediate of the compound (B1a) represented by

  Hereinafter, a synthesis method of the compounds (A1a) and (B1a) will be described.

Compound (A1a)

[Wherein, R ^{A7 to} R ^A15 and R ^{A17 to} R ^A18 are the same as defined above. ]

  Here, a compound (A1a) can be obtained by causing a Friedel-Crafts reaction by causing a Lewis acid catalyst to act on the compound (A2a).

  Examples of Lewis acid catalysts that can be used include aluminum chloride, iron (II) chloride, iron (III) chloride, trifluoroborane / diethyl ether complex, titanium chloride (IV), tin (II) trifluoromethanesulfonate, and trifluoromethanesulfonic acid. Bismuth (III), scandium trifluoromethanesulfonate (III) and the like can be mentioned, but in view of reactivity, scandium (III) trifluoromethanesulfonate is preferable.

  0.1-5 mol is preferable with respect to 1 mol of compounds (A2a), and, as for the usage-amount of a Lewis' acid catalyst, 1.5-2.5 mol is more preferable.

  This reaction is usually performed in a solvent. The solvent is preferably a nonpolar solvent, and halogen solvents such as methylene chloride and 1,2-dichloroethylene, and aromatic solvents such as benzene and toluene are used.

  There are no particular limitations on the conditions for this reaction. The reaction time can be 1 to 24 hours, preferably 4 to 20 hours. Although reaction temperature changes with solvents, it can be set as -80-200 degreeC, for example, Preferably it is 20-100 degreeC. The reaction atmosphere is not particularly limited. Specific examples of the reaction atmosphere include an air atmosphere and an inert gas atmosphere. As long as the target compound can be obtained, other substances may be added to the reaction system.

Compound (B1a)

[Wherein, R ^{B9 to} R ^B22 are the same as defined above. ]

  Here too, similarly to the reaction from compound (A2a) to compound (A1a), a Lewis acid catalyst is allowed to act to cause a Friedel-Crafts reaction to obtain compound (B1a).

  Examples of the Lewis acid catalyst that can be used include those described above.

  0.5-8 mol is preferable with respect to 1 mol of compounds (B2a), and, as for the usage-amount of a Lewis' acid catalyst, 3.5-4.5 mol is more preferable.

  This reaction is usually performed in a solvent. The solvent is preferably a nonpolar solvent, and halogen solvents such as methylene chloride and 1,2-dichloroethylene, and aromatic solvents such as benzene and toluene are used.

  There are no particular limitations on the conditions for this reaction. The reaction time can be 1 to 24 hours, preferably 4 to 20 hours. Although reaction temperature changes with solvents, it can be set as -80-200 degreeC, for example, Preferably it is 20-100 degreeC. The reaction atmosphere is not particularly limited. Specific examples of the reaction atmosphere include an air atmosphere and an inert gas atmosphere. As long as the target compound can be obtained, other substances may be added to the reaction system.

<Compound (C1)>
If a group having a π bond is introduced into the π-conjugated organoboron compound of the present invention obtained as described above, the π-conjugated system can be further expanded. Here, among the compounds in which such a π-conjugated system is expanded, as a typical example, the general formula (C1):

[Wherein R ^{C1 to} R ^C12 are the same or different, and each represents a hydrogen atom and an alkyl group having 1 to 20 carbon atoms; R ^{C13 to} R ^C16 are the same or different, and each represents a hydrogen atom, a halogen atom, a boronic acid, or Ester group, silyl group or stannyl group; Y is a group having a π bond. ]
A π-conjugated organoboron compound (C1) represented by general formula (A1a-1):

[Wherein, R ^{A7 to} R ^A12 are the same or different and are each a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; and R ^A16 is a halogen atom. ]
A synthesis method using the compound (A1a-1) represented by

  Here, the π-conjugated organoboron compound (C1) is obtained by cross-coupling reaction represented by Suzuki-Miyaura coupling between the compound (A1a-1) and the organometallic compound.

  Examples of organometallic compounds that can be used here include organoboron compounds, organomagnesium compounds, organotin compounds, organozinc compounds, and organosilicon compounds.

Specifically, the general formula (4):
Z-Y-Z
[Wherein Y is a group having a π bond; two Z's are the same or different and each represents a general formula (5):

(Two R ^{1 s} may be the same or different and each may be a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, or two R ^1s may be bonded to each other to form a ring. .)
-MgX (X is a halogen atom), -SnR ₃ (R is an alkyl group), -ZnX (X is a halogen atom), -SiR _n X _3-n (R is an alkyl group, X is a halogen atom) , N is an integer of 0-3). ]
And the like.

  Here, as for the usage-amount of an organometallic compound, 0.3-0.6 mol is preferable with respect to 1 mol of compounds (A1a-1), and 0.45-0.5 mol is more preferable.

  The reaction is usually carried out in the presence of a catalyst, and preferably a palladium complex is used. This palladium complex has the formula:

[Wherein XPhos is 2-dicyclohexylphosphino-2 ′, 4 ′, 6′-triisopropylbiphenyl. ]
Is preferred.

  0.01-0.5 mol is preferable with respect to 1 mol of compounds (A1a-1), and, as for the usage-amount of a palladium complex, 0.02-0.1 mol is more preferable.

In this reaction, a ligand may be used together with the palladium complex. When using a ligand, Pd (PPh ₃ ) ₄ , PdCl ₂ (PPh ₃ ) ₂ , Pd ₂ (dba) ₃ and PPh ₃ , P (o-tolyl) ₃ , P (t-Bu) ₃ , ligands such as XPhos and SPhos may be used together.

  In addition to the palladium complex, a base (boron atom activator) may be used as necessary. This base is not particularly limited as long as it is a compound that can form an art complex on a boron atom in a cross-coupling reaction. Specifically, potassium fluoride, cesium fluoride, sodium hydroxide, potassium hydroxide, sodium methoxide, sodium bicarbonate, potassium bicarbonate, sodium carbonate, potassium carbonate, cesium carbonate, potassium phosphate, sodium acetate, acetic acid Examples include potassium and calcium acetate. Of these, cesium fluoride, cesium carbonate, and potassium phosphate are preferable.

  What has been described above is merely a typical example, and various compounds with an expanded π-conjugated system can be synthesized by appropriately changing the raw materials and the like in the same manner.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not restrict | limited at all by these Examples.

In the present Example, melting | fusing point was measured using the trace amount melting | fusing point measuring apparatus made from Yanaco apparatus. ¹ H, ¹¹ B, ¹³ C NMR spectra were measured using JEOL AL-400 ( ¹ H: 400 MHz, ¹³ C: 100 MHz, ¹¹ B: 128 MHz). Chemical shifts are expressed in ppm. The residual solvent in the heavy solvent is used as the internal standard for ¹ H and ¹³ C NMR measurements, and BF ₃ · OEt ₂ (Et: ethyl group; 0 ppm) is used for the ¹¹ B NMR measurement. Used as standard. Mass spectrometry was measured using a JEOL Bruker micrOTOF Focus. The UV-visible absorption spectrum was measured using Shimadzu UV-3150, the fluorescence spectrum was measured using Hitachi F-4500, and the absolute quantum yield was measured using the Hamamatsu Photonics C9920-02 system. Column chromatography was performed using Fuji Silysia PSQ 100B. The reaction was carried out in an Ar atmosphere using a dried container and a dehydrating solvent unless otherwise specified. The THF used for the measurement of optical properties was obtained by bubbling a solvent made by Nacalai Tesque with Ar. In the reaction using the Pd catalyst, the above dehydrated solvent was used after bubbling Ar for 30 minutes or more. 4-Bromo-2,6-dimethyliodobenzene:

Was synthesized according to the literature (Non-patent Document 2).

  In order to incorporate a plane-fixed borane moiety into a π-electron system, it is necessary to synthesize a derivative having a functional group for structural modification by metalation or coupling. As such a key precursor, in Example 1, a monobromo-plane-fixed borane having a bromine atom:

4-bromo-2,6-dimethylaniline:

Synthesized starting from

  [Synthesis Example 1: 4-bromo-2,6-dimethyliodobenzene]

  4-Bromo-2,6-dimethylaniline is diazotized with sodium nitrite and hydrochloric acid at 0 ° C. in acetonitrile, and the amino group is converted to iodine by adding potassium iodide to give 4-bromo-2,6 -Dimethyl iodobenzene was obtained with a yield of 96%. This method is a known method described in the literature (Non-Patent Document 2).

  [Synthesis Example 2: Dimethyl 5-bromo-2-iodo-1,3-benzenedicarboxylate]

  The methyl group of 4-bromo-2,6-dimethyliodobenzene obtained in Synthesis Example 1 was oxidized with potassium permanganate to obtain a dicarboxylic acid, and then thionyl chloride was allowed to act in methanol to give a dimethyl dicarboxylate. Yield 77%. Specifically, it is as follows.

  Potassium permanganate (99.6 g, 630 mmol) in a suspension (410 mL) of 4-bromo-2,6-dimethyliodobenzene (37.7 g, 121 mmol) in t-butanol / water (1: 1 by volume). And Celite (registered trademark) (about 80 g) were added, and the mixture was heated to reflux for 16.5 hours. The precipitate was filtered off and washed with methanol, and the filtrate was concentrated to about one third by distilling off the solvent under reduced pressure. To this was added 100 mL of concentrated hydrochloric acid, and the resulting white precipitate was suction filtered and dried to give 5-bromo-2-iodo-1,3-benzenedicarboxylic acid:

Of crude product as a white solid (38.6 g).
¹ H NMR (270 MHz, DMSO-d ₆ ) δ 7.78 (s, 2H).

Used in the next synthesis without further purification. Methanol (192 mL) was added to the white solid, and thionyl chloride (SOCl ₂ , 23 mL, 315 mmol) was added dropwise at 0 ° C. over 15 minutes, followed by stirring for 12 hours under heating and reflux. After allowing to cool to room temperature, 125 mL of water was added and extracted three times with dichloromethane. The organic phase was washed with saturated aqueous sodium hydrogen carbonate solution and saturated brine, and dried over anhydrous magnesium sulfate. The white solid obtained by filtering off magnesium sulfate and evaporating the solvent under reduced pressure was purified by column chromatography (silica gel, ethyl acetate) to obtain 37.2 g (93 mmol) of 5-bromo-2-iodo Dimethyl 1,3-benzenedicarboxylate:

Was obtained as a white solid in 77% yield.
Dimethyl 5-bromo-2-iodo-1,3-benzenedicarboxylate: mp 86-87 ° C .; ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.75 (s, 2H), 3.96 (s, 6H); ¹³ C {H} NMR (100 MHz, CDCl ₃ ) δ166.62, 141.95, 134.20, 122.12, 90.09, 53.04; HRMS (APCI, positive) calcd for C ₁₀ H ₈ BrIO ₄ m / z 397.8651, found: 397.8654.

  [Synthesis Example 3: 4-bromo-2,6-di (2-hydroxy-2-propyl) iodobenzene]

  A dihydroxy compound was obtained in a yield of 24% by allowing 5.5 mol of methylmagnesium iodide to act on 1 mol of dimethyl 5-bromo-2-iodo-1,3-benzenedicarboxylate obtained in Synthesis Example 2. It was. Specifically, it is as follows.

  Dried magnesium (3.95 g, 162 mmol) was immersed in a small amount of diethyl ether, and a solution of iodomethane (13.5 mL, 217 mmol) in diethyl ether (137 mL) was added dropwise at room temperature over 1.5 hours. For 1 hour. A THF solution (114 mL) of dimethyl 5-bromo-2-iodo-1,3-benzenedicarboxylate (15.9 g, 39.7 mmol) obtained in Synthesis Example 2 was added dropwise at room temperature over 1 hour, and heated under reflux. At 15.5 h, the solution turned from orange to brown and a white solid precipitated. Iodine (about 10 g, about 39 mmol) and THF (30 mL) were added and stirred for 3 hours while allowing to cool to room temperature. A saturated aqueous ammonium chloride solution and a saturated aqueous sodium sulfite solution were added to separate the organic phase and the aqueous phase. The aqueous phase was extracted with dichloromethane, added to the organic phase, and dried over anhydrous magnesium sulfate. Magnesium sulfate was filtered off, the solvent was distilled off under reduced pressure, and the resulting brown liquid was purified by recrystallization from dichloromethane to obtain 3.84 g (9.63 mmol) of 4-bromo-2,6-di (2-Hydroxy-2-propyl) iodobenzene:

Was obtained as a white solid in 24% yield.

In this reaction, a halogen-metal exchange reaction between the 1st-position iodine atom and the Grignard reagent occurred along with the nucleophilic attack on the ester group of the intended Grignard reagent. Tried to iodinate.
4-Bromo-2,6-di (2-hydroxy-2-propyl) iodobenzene: mp 147-148 ° C .; ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.72 (s, 2H), 1.84 (s, 12H ); ¹³ C {H} NMR (100 MHz, CDCl ₃ ) δ152.08, 129.38, 123.24, 92.20, 75.25, 30.63; HRMS (APCI, positive) calcd for C ₁₂ H ₁₆ BrIO ₂ m / z 397.9378, found: 397.9366.

  [Synthesis Example 4: 4-bromo-2,6-diisopropylphenyliodobenzene]

  Next, 4-bromo-2,6-di (2-hydroxy-2-propyl) iodobenzene was dehydrated using p-toluenesulfonic acid monohydrate to obtain an olefin compound with a yield of 97%. It was. Specifically, it is as follows.

  This experiment was performed under air. 4-Bromo-2,6-di (2-hydroxy-2-propyl) iodobenzene (3.84 g, 9.63 mmol) obtained in Synthesis Example 3 and p-toluenesulfonic acid monohydrate (0.372 g, 1.95 mmol) was dissolved in toluene (50 mL) and stirred for 1 hour under heating to reflux. After allowing to cool to room temperature, saturated aqueous sodium hydrogen carbonate solution was added, and the mixture was separated into an organic phase and an aqueous phase. The aqueous phase was extracted three times with diethyl ether, added to the organic phase, and dried over anhydrous magnesium sulfate. The orange brown liquid obtained by filtering off magnesium sulfate and distilling off the solvent under reduced pressure was purified by column chromatography (silica gel, hexane) to give 3.39 g (9.33 mmol) of 4-bromo-2. , 6-Diisopropylphenyliodobenzene:

Was obtained as a white solid in 97% yield.
4-Bromo-2,6-diisopropylphenyliodobenzene: mp 47-48 ° C .; ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.19 (s, 2H), 5.23 (s, 2H), 4.90 (s, 2H) , 2.06 (s, 6H); ¹³ C {H} NMR (100 MHz, CDCl ₃ ) δ 151.51, 148.17, 129.31, 122.00, 116.48, 98.08, 23.83; HRMS (APCI, positive) calcd for C ₁₂ H ₁₂ BrI m / z 361.9167, found: 361.9168.

  Example 1: 9- (4-Bromo-2,6-diisopropylphenyl) -9,10-dihydro-9-boranthracene

  Furthermore, 1 mol of n-butyllithium was allowed to act on 1 mol of 4-bromo-2,6-diisopropylphenyliodobenzene obtained in Synthesis Example 4 to monolithiate the 1-position, and subsequently to 1 mol of raw material. 9- (4-bromo-2,6-diisopropylphenyl) -9,10-dihydro-9 by reacting with 1 mol of boron reagent (9-bromo-9,10-dihydro-9-boranthracene). -Boraanthracene was obtained in a yield of 77%. Specifically, it is as follows.

  To a toluene solution (48 mL) of 4-bromo-2,6-diisopropylphenyliodobenzene (3.34 g, 9.20 mmol) obtained in Synthesis Example 4 was added an n-butyllithium-pentane solution (6.0 mL, 9.60 mmol). Was added dropwise at 0 ° C. over 10 minutes. After slowly warming to room temperature and stirring for 6 hours, the yellow solution turned into an orange suspension and then a yellow suspension. There 9-bromo-9,10-dihydro-9-boraanthracene:

Toluene solution (30 mL) was added dropwise at 0 ° C., and the mixture was warmed to room temperature and stirred for 4.5 hours. Saturated aqueous sodium hydrogen carbonate solution was added to separate the organic phase and the aqueous phase. The aqueous phase was extracted three times with diethyl ether, combined with the organic phase and dried over anhydrous magnesium sulfate. By filtering off magnesium sulfate and distilling off the solvent under reduced pressure, the yellow solid obtained was purified by column chromatography (silica gel, hexane: dichloromethane = 4: 1 by volume) to obtain 2.94 g (7. 12 mmol) 9- (4-Bromo-2,6-diisopropylphenyl) -9,10-dihydro-9-boraanthracene:

Was obtained as a white solid in 77% yield.
9- (4-Bromo-2,6-diisopropylphenyl) -9,10-dihydro-9-boraanthracene: mp 167-168 ° C .; ¹ H NMR (400 MHz, CD ₂ Cl ₂ ) δ 7.60 (d, J _HH = 7.59 Hz, 2H), 7.50 (m, 6H), 7.26 (m, 2H), 4.64 (s, 2H), 4.50 (s, 2H), 4.44 (s, 2H), 1.89 (s, 6H) ¹¹ B NMR (128 MHz, CD ₂ Cl ₂ ) δ59.11; ¹³ C {H} NMR (100 MHz, CD ₂ Cl ₂ ) δ 149.07, 146.85, 146.76, 137.15, 132.13, 128.50, 128.38, 125.84, 121.61 , 117.77, 38.44, 24.05; HRMS (APCI, positive) calcd for C ₂₅ H ₂₂ BBr m / z 412.0998, found: 412.1001.

  [Example 2: Monobromoplanar fixed borane]

  9- (4-Bromo-2,6-diisopropylphenyl) -9,10-dihydro-9-boraanthracene obtained in Example 1 was treated with 1,2-dichloroethane by using scandium (III) trifluoromethanesulfonate as a Lewis acid catalyst. By allowing the reaction to occur under moderate heating and reflux, the intramolecular Friedel-Crafts reaction proceeded, and the desired monobromoplanar borane could be obtained in a yield of 58%. Specifically, it is as follows.

  9- (4-Bromo-2,6-diisopropylphenyl) -9,10-dihydro-9-boraanthracene (1.01 g, 2.43 mmol) obtained in Example 1 and scandium (III) trifluoromethanesulfonate (III) ( (2,38 g, 4.84 mmol) was added 1,2-dichloroethane (600 mL), and the mixture was stirred for 54 hours under reflux with heating. After allowing to cool to room temperature, a saturated aqueous sodium hydrogen carbonate solution was added to separate the organic phase and the aqueous phase, the aqueous phase was extracted with dichloromethane, combined with the organic phase, and dried over anhydrous magnesium sulfate. The magnesium sulfate was filtered off, and the solvent was distilled off under reduced pressure. The resulting tan solid was purified by column chromatography (silica gel, hexane: dichloromethane = 4: 1 (volume ratio)) to obtain 555.5 mg. (1.42 mmol) monobromoplanar borane:

Was obtained as a white solid in 58% yield.
Monobromoplanar fixed borane: melting point 234-235 ° C; ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.80 (s, 2H), 7.68 (m, 4H), 7.43 (d, J _HH = 6.79 Hz, 2H), 4.59 (s, 2H), 1.78 (s, 12H); ¹¹ B NMR (128 MHz, CDCl ₃ ) δ 45.06; ¹³ C {H} NMR (100 MHz, CDCl ₃ ) δ 158.21, 155.67, 146.15, 132.56, 128.36, 127.58, 125.24, 123.89, 42.94, 37.36, 34.29, 2; HRMS (APCI, positive) calcd for C ₂₅ H ₂₂ ¹¹ BBr m / z 412.0998, found: 412.1002.

  As shown in the test examples described below, this compound can be handled in the air despite its lack of steric protection by bulky substituents, and is stable enough to be purified by silica gel column chromatography. It was.

  This compound is also a Lewis base amine

Did not react.

  [Example 3: Planar-fixed borane-substituted thiophene]

  The plane-fixed borane-substituted thiophene was synthesized by Suzuki-Miyaura cross coupling between the monobromo plane-fixed borane obtained in Example 2 and 2,5-thiophene diboronic acid.

  Here, the Pd complex reported by Buchwald et al. In 2010:

[Wherein XPhos is 2-dicyclohexylphosphino-2 ′, 4 ′, 6′-triisopropylbiphenyl. ]
Was studied as a catalyst. This Pd complex has a fast initiation reaction, promotes the transmetalation of arylboronic acid, and can proceed under mild conditions of room temperature to 40 ° C. Therefore, perfluorophenylboronic acid, heteroarylboronic acid It is said that it is effective when using boronic acid which is unstable under the coupling conditions such as (Non-Patent Document 3). When this Pd complex is used to react 2 mol of monobromo plane-fixed borane with 1 mol of thiophene diboronic acid in an aqueous solution of THF / K ₃ PO ₄ at 40 ° C., the coupling reaction proceeds, and the target compound:

Generation was confirmed. By purifying the reaction mixture by silica gel column chromatography, the planar borane-substituted thiophene was successfully obtained as a yellow solid in a yield of 57%. Specifically, it is as follows.

  Monobromoplanar-fixed borane (417.8 mg, 1.01 mmol) obtained in Example 2, 2,5-thiophenediboronic acid:

(87.0 mg, 0.506 mmol), Pd complex:

[Wherein XPhos is 2-dicyclohexylphosphino-2 ′, 4 ′, 6′-triisopropylbiphenyl. ]
(43.1 mg, 54.8 μmol) was added THF (1 mL) and an aqueous solution (2 mL) of tripotassium phosphate (214.8 mg, 1.01 mmol), and the mixture was stirred for 3 hours with heating under reflux, then at 23 ° C. Stir for 5 hours. On the way, a THF solution (0.5 mL) of 2,5-thiophenediboronic acid (43.7 mg, 0.254 mmol) was added in two portions. After allowing to cool to room temperature, the organic phase and the aqueous phase were separated. The aqueous phase was extracted 3 times with dichloromethane, combined with the organic phase and dried over anhydrous magnesium sulfate. The magnesium sulfate was removed by filtration, and the yellow solid obtained by distilling off the solvent under reduced pressure was purified by column chromatography (silica gel, hexane: chloroform = 7: 3 (volume ratio)) to give 216.5 mg (0 .289 mmol) of plane-fixed borane-substituted thiophene as a yellow solid in 57% yield.
Planar-fixed borane-substituted thiophene: mp 137-138 ° C (decomposition); ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.98 (s, 4H), 7.68 (m, 8H), 7.59 (s, 2H), 7.45 (d , J _HH = 6.8 Hz, 4H), 4.62 (s, 4H), 1.90 (s, 24H); ¹¹ B NMR (128 MHz, CDCl ₃ ) δ 45.97; ¹³ C {H} NMR (100 MHz, CDCl ₃ ) δ 157.21, 156.34, 146.26, 145.53, 138.33, 132.53, 125.35, 125.07, 124.14, 121.88, 43.20, 37.59, 34.69; HRMS (APCI, positive) calcd for C ₅₄ H ₄₇ ¹¹ B ₂ S [M + H] ⁺ m / z 749.3596, found: 746.3592.

  [Comparative Example 1: Reference compound]

  In order to investigate the effect of the plane-fixed borane-substituted thiophene obtained in Example 3 on the physical properties of the boron substituent, 1,5-bis (3,5-dimethylphenyl) thiophene as a central skeleton was used as a reference compound. It was synthesized by a Suzuki-Miyaura cross-coupling reaction between bromo-3,5-dimethylbenzene and 2,5-thiophenediboronic acid. Specifically, it is as follows.

  2,5-thiophene diboronic acid (171.2 mg, 0.997 mmol), Pd complex:

[Wherein XPhos is 2-dicyclohexylphosphino-2 ′, 4 ′, 6′-triisopropylbiphenyl. ]
(46.7 mg, 59.4 μmol), 1-bromo-3,5-dimethylbenzene:

An aqueous solution (4 mL) of tripotassium phosphate (419.7 mg, 1.99 mmol) was added to a THF solution (2 mL) of (373.4 mg, 2.02 mmol), and the mixture was stirred at room temperature for 21 hours. The organic phase and the aqueous phase were separated, the aqueous phase was extracted three times with diethyl ether, combined with the organic phase, and dried over anhydrous magnesium sulfate. Magnesium sulfate was filtered off, the solvent was distilled off under reduced pressure, and the resulting brown solid was purified by column chromatography (silica gel, hexane), whereby 100.9 mg (0.345 mmol) of 2,5-bis ( 3,5-dimethylphenyl) thiophene:

Was obtained as a white solid in 35% yield.
2,5-bis (3,5-dimethylphenyl) thiophene: mp 106-107 ° C; ¹ H NMR (400 MHz, acetone-d ₆ ) δ 7.41 (s, 2H), 7.32 (s, 4H), 6.96 ( s, 2H), 2.34 (s, 12H); ¹³ C {H} NMR (100 MHz, acetone-d ₆ ) δ144.32, 139.50, 135.15, 130.21, 125.09, 124.20, 21.44; HRMS (APCI, positive) calcd for C ₂₀ H ₂₁ S [M + H] ⁺ m / z 293.1358, found: 293.1310.

[Test Example 1: Optical properties]
The flat-fixed borane-substituted thiophene obtained in Example 3 was measured for UV-visible absorption spectrum, fluorescence spectrum, and absolute fluorescence quantum yield in a THF solution. Moreover, in order to consider the effect of incorporating plane-fixed boron into the π-conjugated skeleton, the same measurement was performed on the reference compound obtained in Comparative Example 1. The results are shown in Table 1 and FIG. In FIG. 1, 14 represents a plane-fixed borane-substituted thiophene obtained in Example 3, and 26 represents a reference compound obtained in Comparative Example 1.

The plane-fixed borane-substituted thiophene obtained in Example 3 exhibits an absorption maximum at 391 nm (ε = 5.64 × 10 ⁴ M ⁻¹ cm ⁻¹ ), and has a strong blue fluorescence (Φ _F = 0.92). On the other hand, the reference compound obtained in Comparative Example 1 exhibits absorption at a maximum absorption wavelength of 330 nm (ε = 2.81 × 10 ⁴ M ⁻¹ cm ⁻¹ ) and weak fluorescence at a maximum wavelength of 395 nm (Φ _F = 0.17). Indicated. Since the absorption and fluorescence spectrum shapes of the plane-fixed borane-substituted thiophene obtained in Example 3 and the reference compound obtained in Comparative Example 1 are almost the same, these are considered to be derived from the same transition. . From these results, it was found that by introducing a plane-fixed borane moiety into a π-conjugated skeleton called diphenylthiophene, the π-conjugated system was effectively expanded, and absorption and fluorescence spectra were observed at longer wavelengths. In addition, compared with the plane-fixed borane-substituted thiophene obtained in Example 3, the reference compound obtained in Comparative Example 1 showed a significant increase in the molar extinction coefficient ε and the absolute fluorescence quantum yield Φ _F , between the ground state and the excited state. It was suggested that the transition probabilities, deactivation pathways, etc. are different.

[Test Example 2: X-ray crystal structure analysis]
Intensity data was obtained at 123K using a Rigaku Single Crystal CCD X-ray diffractometer (Saturn 70 with MicroMax-007, Mo Kα irradiation (λ = 0.71070 mm), Vari Max).

Crystals of the reference compound obtained in Comparative Example 1 were obtained by recrystallization from cyclohexane. The structure was solved by the direct method F ² (SHELXS-97 (Non-Patent Document 4)) and optimized by full-matrix least-squares on F ² (SHELXS-97). The non-hydrogen atoms were optimized anisotropically, and the hydrogen atoms were arranged using AFIX instructions. Crystal data: C ₂₀ H ₂₀ S; FW = 292.42, Orthorhombic, Pbca, a = 13.665 (15) Å, b = 16.268 (12) Å, c = 14.394 (11) Å, V = 3200 (5) Å ³ , Z = 8, D _c = 1.214 g / cm ³ , F (000) = 1248, Reflections collected = 19484, Independent reflections = 2772 [R (int) = 0.0310], GOF = 1.192, R ₁ [I> 2σ (I )] = 0.0398, wR ₂ (all data) = 0.1611.

  The X-ray crystal structure of the reference compound obtained in Comparative Example 1 is shown in FIG.

Crystals of the plane-fixed borane-substituted thiophene obtained in Example 3 were obtained by recrystallization by a chloroform / hexane vapor diffusion method. The structure was solved by the direct method F ² (SHELXS-97 (Non-Patent Document 4)) and optimized by full-matrix least-squares on F ² (SHELXS-97). The electron density observed in a complicated manner derived from the solvent molecules contained in the crystal lattice was removed using PLATON's SQUEESE program (Non-Patent Documents 5 to 6). For non-hydrogen atoms, the electron density anisotropy was optimized by limiting ISOR 0.001 and SIMU 0.005. Hydrogen atoms were placed using AFIX instructions. Crystal data: C ₅₄ H ₄₆ B ₃ S; FW = 748.59, Monoclinic, P2 ₁ , a = 14.544 (11) Å, b = 26.440 (19) Å, c = 25.33 (3) Å, β = 93.68 (2) °, V = 9719 (16) Å ³ , Z = 8, D _c = 1.023 g / cm ³ , F (000) = 3168, Reflections collected = 64636, Independent reflections = 25657 [R (int) = 0.0480], GOF = 1.195, R ₁ [I> 2σ (I)] = 0.1110, wR ₂ (all data) = 0.3099.

  The results are shown in Table 2 and FIG.

  In the crystal structure of the plane-fixed borane-substituted thiophene obtained in Example 3, there were four crystallographically independent molecules in the unit cell. They had different values of dihedral angles α and β formed by the planar borane site and thiophene.

  Focusing on the plane-fixed borane site, this skeleton feature was also found in the CB bond distance. The results are shown in Table 3. In Table 3, the plane-fixed borane is a formula:

It can be synthesized by the same route as the route from Synthesis Example 1 to Example 2. Mes ₃ B is a formula:

It is a compound shown by.

From Table 3, the plane-fixed borane-substituted thiophene obtained in Example 3 was clearly shorter than the CB bond distance in Mes ₃ B (Non-patent Document 1). Since this tendency is also observed in the plane-fixed borane, it is considered that the CB bond is shortened by cross-linking three aryl groups on boron with a methylene group.

  Furthermore, the packing structure is shown in FIG.

  There were voids with a diameter of about 1 to 1.4 nm in the crystal structure, and solvent molecules were taken in. It is considered that the plane borane site of the plane-fixed borane-substituted thiophene obtained in Example 3 cannot form effective π-π stacking due to steric hindrance of two methyl groups bonded to the methylene group. Therefore, it is considered that the plane borane sites are aggregated by the CH ... π interaction, and the generated voids are filled with solvent molecules to form such a complicated crystal structure.

[Test Example 3: Theoretical calculation]
In order to consider the difference between the UV-visible absorption spectrum and the fluorescence spectrum of the planar borane-substituted thiophene obtained in Example 3 and the reference compound obtained in Comparative Example 1, structural optimization and TD-DFT calculation were performed by molecular orbital calculation. . The results are shown in FIG.

  From this result, it was found that the absorptions of the planar borane-substituted thiophene obtained in Example 3 and the reference compound obtained in Comparative Example 1 were both attributed to the transition from HOMO to LUMO that spread throughout the molecule. . Although the HOMO does not show a significant difference by introducing the boron site, the LUMO energy level is greatly reduced by p-π * conjugation, and the HOMO-LUMO gap is reduced. It was. This is consistent with the fact that the absorption and fluorescence spectra of the planar borane-substituted thiophene obtained in Example 3 were shifted by a longer wavelength compared to the reference compound obtained in Comparative Example 1. The oscillator strength f is f = 0.9014 in the reference compound obtained in Comparative Example 1, whereas f = 1.4719 is obtained in the planar borane-substituted thiophene obtained in Example 3, so that the molar extinction coefficient ε is increased. It agrees with the experimental facts.

  Example 4: 9,10-bis [2,6- (prop-1-en-2-yl) phenyl] -9,10-diboraanthracene (10)]

N-Butyllithium (1.6 M hexane solution, 0.80 mL, 1.09 mmol) was added dropwise to a toluene solution (5 mL) of 2,6-diisopropylphenyliodobenzene (S3; 244.8 mg, 1.03 mmol) at 0 ° C. . After stirring at room temperature for 6.5 hours, a toluene solution (5 mL) of 9,10-diboraanthracene (9; 174.3 mg, 0.52 mmol) was added. The reaction mixture was stirred at room temperature for 12 hours. Water was added to the reaction mixture, and extraction was performed with dichloromethane. The obtained organic phase was dried over anhydrous magnesium sulfate and filtered, and the filtrate was concentrated under reduced pressure. Separation was performed by silica gel column chromatography (dichloromethane / hexane = 1/5, R _f = 0.35), and 148.3 mg (0.30 mmol) of the target product 10 was obtained as a colorless solid in a yield of 58%.
Melting point: 255.0-256.0 ° C. ¹ H NMR (400 MHz, CD ₂ Cl ₂ ) δ (7.53-7.50, m, 4H), 7.44-7.42 (m, 2H), 7.40-7.36 (m, 6H), 4, 61 (d, J _HH = 1.6 Hz, 2H), 4,60 (d, J _HH = 7.6 Hz, 2H), 1.96 (s, 2H); ¹³ CNMR δ (148.5, 147.0, 137.4, 131.7, 127.5, 125.6 , 116.5, 24.2; ¹¹ BNMR (128 MHz, CD ₂ Cl ₂ ) δ 61.7 ppm (h _1/2 = 1000 Hz). HRMS cald for C ₃₆ H ₃₄ B ₂ , 488.2847, found. 488.2863.

  [Example 5: Planar 9,10-diphenyl-9,10-dihydro-9,10-diboraanthracene (4)]

Sc (OTf) ₃ (528.3 mg, 1.07 mmol) and 9,10-bis [2,6- (prop-1-en-2-yl) phenyl] -9,10-diboraanthracene (10) (111 mg , 0.27 mmol) was added 1,2-dichloroethane (100 mL) and refluxed for 24 hours. 30 mL of water was added to the reaction mixture, and extraction was performed using dichloromethane. The obtained organic phase was dried over anhydrous magnesium sulfate and filtered, and the filtrate was concentrated under reduced pressure. Separation was performed by silica gel column chromatography (dichloromethane / hexane = 1/5, R _f = 0.40) to obtain 28 mg (0.068 mmol) of the target product 4 as a colorless solid in a yield of 25%.
Melting point> 300 ° C; ¹ H NMR (300 MHz, CDCl ₃ ) δ 7.99 (s, 4H), 7.76 (q, 2H, J _HH = 7.76 Hz), 7.72 (t, 4H, J _HH = 7.76 Hz), 1.83 (s, 24); ¹³ C NMR (75 MHz, CDCl ₃ ) δ 156.7, 154.2, 132.8, 131.3, 124.2, 42.5, 33.4; ¹¹ B NMR (128 MHz, CDCl ₃ ) δ 48.4 ppm (h _1/2 = 1000 Hz); HRMS cald for C ₃₆ H ₃₄ B ₂ , 488.2847, found.488.2852. Anal. Calcd for C ₃₆ H ₄₂ B ₂ : C, 88.55; H, 7.02. Found: C, 88.30; H, 7.02.

  [Example 6: Carbonyl-bridged planar triphenylborane (8)]

CrO ₃ (18.3 mg, 0.180 mmol) was added to an acetic acid solution (10 mL) of compound 7 (40.7 mg, 0.122 mmol), and heated to reflux for 1 hour. Water was added to the reaction mixture, and extraction was performed using dichloromethane. The obtained organic phase was dried over anhydrous magnesium sulfate and filtered, and the filtrate was concentrated under reduced pressure. Separation was performed by silica gel column chromatography (dichloromethane / hexane = 1/1, R _f = 0.30), and 27.7 mg (0.078 mmol) of the target product 8 was obtained as a colorless solid in a yield of 65%.
Melting point: 289-290 ° C. ¹ H NMR (300 MHz, CDCl ₃ ) δ 8.28 (dd, 2H, J _HH = 7.5 Hz, 0.9 Hz), 7.97 (dd, 2H, J _HH = 7.5 Hz, 0.9 Hz), 7.80 (t, 3H, J _HH = 7.5 Hz), 7.69 (d, 2H, J _HH = 7.5 Hz), 1.81 (s, 12H); ¹³ C NMR (75 MHz, CDCl ₃ ) δ 189.3, 156.5, 156.0, 138.2, 134.2, 133.5, 132.9 (br), 131.4, 128.7 (br), 125.6, 124.3, 43.0, 33.5 ppm; ¹¹ BNMR (128 MHz, CDCl ₃ ) δ 45.3 ppm (h _1/2 = 770 Hz). HRMS cald for C ₂₅ H ₂₁ BO, 348.1685 found, 348.1670.

  [Example 7: Planar-fixed triphenylborane derivative (1)]

TiCl ₄ (2.5 mL, 1 M dichloromethane solution, 2.5 mmol) was diluted with 10 mL dichloromethane, and dimethylzinc in toluene (2 M, 1.26 mL, 2.52 mmol) was added to the solution at −25 ° C. After stirring at the same temperature for 30 minutes, a dichloromethane solution (12 mL) of the compound 8 (87.5 mg, 0.251 mmol) obtained in Example 6 was slowly added. The reaction mixture was then stirred at −25 ° C. for 12 hours. Water was added to the reaction mixture, and extraction was performed using dichloromethane. The obtained organic phase was dried over anhydrous magnesium sulfate and filtered, and the filtrate was concentrated under reduced pressure. Separation was performed by silica gel column chromatography (dichloromethane / hexane = ¼, R _f = 0.50) to obtain 69.1 mg (0.191 mmol) of the target product 1 as a colorless solid in a yield of 76%.
Melting point: 290.0-291.0 ℃ (sublimation 231.1-232.0 ℃), ¹ H NMR (300 MHz, CDCl ₃ ) δ7.71 (t, 3H, J _HH = 8.0 Hz), 7.66 (d, 6H, J _HH = 8.0 Hz ), 1.80 (s, 18H); ¹ H NMR (300 MHz, THF-d ₈ ) δ 7.68 (br, 9H), 1.76 (s, 18H); ¹³ C NMR (CDCl ₃ , 75 MHz) δ 156.0, 132.7 , 123.9, 42.8, 34.5 ppm; ¹¹ B NMR (128 MHz, CDCl ₃ ). Δ 48.6 ppm (h _1/2 = 1000 Hz). HRMS Calcd for C ₂₇ H ₂₇ B, 362.2206. Found, 362.2188, Anal. Calcd for C ₂₇ H ₂₇ B: C, 89.50; H, 7.51. Found: C, 89.46; H, 7.49.

[Test Example 4: X-ray crystal structure analysis]
The structure of the plane-fixed triphenylborane derivative obtained in Example 7 was solved by the direct method F ² (SHELXS-97 (Non-Patent Document 4)) and optimized by the full-matrix least-squares on F ² (SHELXS-97) did. The non-hydrogen atoms were optimized anisotropically, and the hydrogen atoms were arranged using AFIX instructions. The results are shown in FIG. Crystal data: C ₂₇ H ₂₇ B; FW = 362.30, crystal size 0.20 × 0.20 × 0.10 mm ³ , Orthorhombic, Pbcn, a = 9.8794 (10) Å, b = 18.5005 (18) Å, c = 11.0075 (10) Å , V = 2011.9 (3) Å ³ , Z = 4, D _c = 1.196 g cm ^-3 .The refinement converged to R ₁ = 0.0480, wR ₂ = 0.0696 (I> 2σ (I)), GOF = 1.096

The structure of planar 9,10-diphenyl-9,10-dihydro-9,10-diboraanthracene obtained in Example 5 was solved by the direct method F ² (SHELXS-97 (Non-patent Document 4)), and full-matrix Optimized by least-squares on F ² (SHELXS-97). The results are shown in FIG. The non-hydrogen atoms were optimized anisotropically, and the hydrogen atoms were arranged using AFIX instructions. Crystal data: C ₃₇ H ₃₄ B ₂ Cl ₂ ; FW = 571.16, crystal size 0.08 × 0.08 × 0.02 mm ³ , Monoclinic, C2 / c, a = 27.583 (7) Å, b = 9.566 (2) Å, c = 12.031 (3) Å, β = 104.380 (4) °, V = 3075.0 (13) Å ³ , Z = 4, D _c = 1.234g cm ^-3 .The refinement converged to R ₁ = 0.0650, wR ₂ = 0.1667 ( I> 2σ (I)), GOF = 1.084.

[Test Example 5: Electrochemical characteristics]
Cyclic voltammetry of the planar fixed triphenylborane derivative obtained in Example 7 and the planar 9,10-diphenyl-9,10-dihydro-9,10-diboraanthracene obtained in Example 5 is ALS / chi-617A Measurements were made using an electrochemical analyzer. For the measurement, an electrochemical cell composed of a glassy carbon electrode, a platinum counter electrode, and an Ag / AgNO ₃ reference electrode was used. Using THF as a solvent, the sample and supporting electrolyte ^{_{n-Bu 4 N + PF 6}} - concentrations were prepared in an argon atmosphere so that each becomes 1 mM, in 0.1 M, was measured. The obtained redox potential was corrected based on the redox potential of ferrocene used as an internal standard. The results are shown in FIG.

Claims (12)

Formula (A):

[Wherein, R ^{A1 to} R ^A4 are the same or different and R ^A1 and R ^A4 are each independently a hydrogen atom, and R ^A2 and R ^A3 are each a 1-alkylethenyl group having ³ to 22 carbon atoms. R ^A1 and R ^A2 , R ^A3 and R ^A4 may be bonded to each other to form a 6-membered heterocycle having a boron atom; R ^{A5 to} R ^A6 may be the same or different and each is a hydrogen atom alone Or an alkyl group having 1 to 20 carbon atoms, and R ^A5 and R ^A6 may be combined to form an oxo group. ]
A unit having three reaction points represented by formula (B):

[In the formula, R ^{B1 to} R ^B8 are the same or different, and R ^B1 , R ^B4 , R ^B5 and R ^B8 are each independently a hydrogen atom, R ^B2 , R ^B3 , R ^B6 and R ^B7 are 3 to 3 carbon atoms. 22 1-alkylethenyl groups, R ^B1 and R ^B2 , R ^B3 and R ^B4 , R ^B5 and R ^B6 , R ^B7 and R ^B8 are bonded to each other and have a 6-membered ring having a boron atom Heterocycle may be formed]
A π-conjugated organoboron compound having at least one unit selected from the group consisting of units having two reaction points represented by: The unit represented by the general formula (A) is represented by the general formula (A1):

[Wherein, R ^{A7 to} R ^A10 are the same or different and each is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; R ^{A11 to} R ^A12 are the same or different and are each independently a hydrogen atom or 1 to 20 carbon atoms] R ^A11 and R ^A12 may be combined to form an oxo group. ]
The π-conjugated organoboron compound according to claim 1, which is a unit having three reaction points represented by: The unit represented by the general formula (B) is represented by the general formula (B1):

[Wherein, R ^{B9 to} R ^B16 are the same or different and are each a hydrogen atom or an alkyl group having 1 to 20 carbon atoms]
The π-conjugated organoboron compound according to claim 1, which is a unit having two reaction points represented by: It has 1-3 at least 1 sort (s) chosen from the group which consists of a unit which has 3 reaction points shown by general formula (A), and a unit which has 2 reaction points shown by general formula (B). The π-conjugated organoboron compound according to any one of the above. General formula (A1a):

[Wherein, R ^{A7 to} R ^A10 are the same or different and each is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; R ^{A11 to} R ^A12 are the same or different and are each independently a hydrogen atom or 1 to 20 carbon atoms] R ^A11 and R ^A12 may be combined to form an oxo group; R ^{A13 to} R ^A15 may be the same or different and each may be a hydrogen atom, a halogen atom, a boronic acid or The ester group, silyl group or stannyl group. ]
Or general formula (B1a):

[Wherein, R ^{B9 to} R ^B16 are the same or different and each is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; R ^{B17 to} R ^B18 are the same or different and each represents a hydrogen atom, a halogen atom, a boronic acid, or its An ester group, a silyl group or a stannyl group. ]
The π-conjugated organoboron compound according to any one of claims 1 to 4, which is represented by: Furthermore, the π-conjugated organoboron compound according to any one of claims 1 to 5, which has a group having a π bond. The group having a π bond is a group having a thiophene skeleton, a group having a fluorene skeleton, a group having a thiazole skeleton, a group having a pyridine skeleton, a group having an oxadiazole skeleton, a group having a thiadiazole skeleton, or a benzothiadiazole skeleton. The π-conjugated organoboron compound according to claim 6, which is at least one selected from the group consisting of a group having an arylene group, and an arylene group. General formula (C1):

[Wherein R ^{C1 to} R ^C12 are the same or different and each is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; R ^{C13 to} R ^C16 are the same or different and each represents a hydrogen atom, a halogen atom, a boronic acid, or Ester group, silyl group or stannyl group; Y is a group having a π bond. ]
The π-conjugated organoboron compound according to any one of claims 1, 2, and 4 to 7, represented by: General formula (A1):

[Wherein, R ^{A7 to} R ^A10 are the same or different and each is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; R ^{A11 to} R ^A12 are the same or different and are each independently a hydrogen atom or 1 to 20 carbon atoms] R ^A11 and R ^A12 may be combined to form an oxo group. ]
A method for producing a π-conjugated organoboron compound having a unit having three reaction points represented by general formula (A2a):

[Wherein, R ^{A11 to} R ^A12 are the same or different and are the same as above; R ^{A13 to} R ^A15 are the same or different and are each a hydrogen atom, a halogen atom, a boronic acid or an ester group thereof, a silyl group or a stannyl group; R ^{A17 to} R ^A18 are the same or different and are each an alkyl group having 1 to 20 carbon atoms. ]
The manufacturing method provided with the process of making a Lewis acid catalyst act on the compound shown by these. General formula (B1):

[Wherein, R ^{B9 to} R ^B16 are the same or different and each represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. ]
A method for producing a π-conjugated organoboron compound having a unit having two reaction points represented by:
General formula (B2a):

[Wherein, R ^{B17 to} R ^B18 are the same or different, and each represents a hydrogen atom, a halogen atom, a boronic acid or an ester group thereof, a silyl group, or a stannyl group; R ^{B19 to} R ^B22 are the same or different and each has 1 carbon atom. ˜20 alkyl groups. ]
The manufacturing method provided with the process of making a Lewis acid catalyst act on the compound shown by these. The production method according to claim 9 or 10, wherein the Lewis acid catalyst is scandium (III) trifluoromethanesulfonate. General formula (C1):

[Wherein R ^{C1 to} R ^C12 are the same or different, and each represents a hydrogen atom and an alkyl group having 1 to 20 carbon atoms; R ^{C13 to} R ^C16 are the same or different, and each represents a hydrogen atom, a halogen atom, a boronic acid, or Ester group, silyl group or stannyl group; Y is a group having a π bond. ]
A method for producing a π-conjugated organoboron compound represented by
General formula (A1a-1):

[Wherein, R ^{A7 to} R ^A12 are the same or different and each represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; R ^A16 represents a halogen atom, a boronic acid or an ester group thereof, a silyl group, or a stannyl group. ]
The manufacturing method provided with the process of coupling-reacting the (pi) conjugated organoboron compound shown by these, and an organometallic compound.

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