KR20230108929A - Organoboron Compounds and Method for Manufacturing the same - Google Patents

Abstract

The present invention relates to organoboron compounds and methods for their preparation. More specifically, it relates to an organoboron compound having a naphthalene skeleton, which is used as a reactant or starting material in organic synthesis.
A novel organoboron compound represented by the following general formula G is provided.
<Formula G>

In the general formula G, R1 to R6 each independently represent hydrogen, an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 16 carbon atoms. R7 and R8 each independently represent either hydrogen or an alkyl group having 1 to 6 carbon atoms, and R7 and R8 may bond to each other to form a ring. R9 represents any one of an alkyl group having 1 to 6 carbon atoms.

Description

Organoboron compounds and methods for manufacturing the same {Organoboron Compounds and Method for Manufacturing the same}

The present invention relates to organoboron compounds and methods for their preparation. More specifically, it relates to an organoboron compound having a naphthalene skeleton, which is used as a reactant or starting material in organic synthesis.

Organic compounds can take a variety of structures compared to inorganic compounds, and materials having various functions can be supplied by appropriate molecular design. Because of these advantages, the development of materials for organic boron compounds that can be used as synthetic intermediates or starting materials for various organic compounds is continuously being made.

In general, research on boronic acids did not make much progress until the 1970s, but after the publication of cross-coupling reactions between boronic acid derivatives and organohalogen compounds by Suzuki and Miyaura researchers in Japan in 1979, rapid progress has been made.

In recent years, organic boron compounds have been considered very important as light emitting materials used in OLED displays, and their application fields are expanding to other fields such as pharmaceuticals and pesticides and bioactive materials.

The boron atom is a metal that has many advantages compared to other heavy metal atoms such as iron, ruthenium, iridium or platinum, is non-toxic, relatively convenient to use, and can be used biologically. Compounds containing these borons are materials that exhibit unique optical properties, and can emit light efficiently through strong quantum absorption at low temperatures, and are being researched and developed as lasers, molecular probes, and light emitting materials.

Although various boron compounds are being studied, it is necessary to diversify their types for excellent materials for light emitting devices. In addition, in the method of synthesizing boron compounds, it is also important to study to easily obtain a target product with higher purity, and a more safe and easy-to-purify reaction is required.

Patent Document 1 discloses a novel organic boron compound that can be used for manufacturing an organic light emitting diode, and Patent Documents 2 and 3 provide a novel organic boron compound and disclose an organic light emitting device using the same.

Patent Document 4 relates to the synthesis of aryl or alkane borates, and dioxaborolein compounds having various substituents are disclosed. Among them, boron compounds having a naphthalene skeleton connected with methoxy as a substituent (see Examples 49, 61, and 65 in the specification) have been disclosed, but boron compounds connected with a methylthio group have not been known.

Domestic Patent Registration No. 10-1511020 (Registration date 2015.04.06.) Domestic Patent Publication No. 10-2014-004138 (published on 2014.01.10.) Domestic Patent Registration No. 10-0492243 (Registration date 2005.05.20.) US registered patent US 7,122,694 B2 (registration date 2006.10.17.)

Kwan-yong Lee, “Recent Advances in the Synthesis of Organic Boronic Acids and Their Derivatives”, KISTI Advanced Technology Information Analysis Report, 2006.09.14.

An object of the present invention is to provide novel organoboron compounds useful as reactive agents in organic synthesis. It can contribute to the synthesis of organic light emitting materials with excellent skeletons having better luminous efficiency and device lifespan than conventional materials and having appropriate color coordinates.

Another object of the present invention is to provide a method for producing the organic boron compound described above.

In one aspect, the present invention provides an organoboron compound represented by the general formula G below.

<Formula G>

(However, in the general formula G, R1 to R6 each independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 16 carbon atoms. R7 and R8 are each independently hydrogen and 1 carbon atom represents any one of alkyl groups of 1 to 6. R9 represents any of alkyl groups of 1 to 6 carbon atoms.)

The R7 and R8 are characterized in that they form a ring by bonding to each other.

In another aspect, the present invention is a method for producing an organoboron compound, wherein an organoboron compound represented by the following general formula G is prepared by condensation reaction of a naphthalene derivative having an alkylthio group with an alkenyl boron ester in the presence of a palladium catalyst and a base. provides a way

<Formula G>

In the method for preparing the organic boron compound, the base used is potassium acetate, the palladium catalyst is PdCl 2 (dppf), and the reaction solvent is characterized in that it is prepared using THF.

In order to accelerate the reaction and increase the yield, a phosphine compound of PPh3, P-(o-tolyl)3, or PBu3 is used as an adduct, or a salt of lithium chloride, lithium bromide, or lithium iodide is used as an adduct. to be

The alkenyl boron ester is a 5-membered ring structured dioxaborolane compound, and is composed of Bis(pinacolato)diboron, 2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane, and 2- It is characterized in that any one is selected from methoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane.

The organoboron compounds are useful as light emitting materials for organic light emitting devices.

According to one embodiment of the present invention, it is possible to provide a novel organoboron compound and a manufacturing method thereof. This organic boron compound can be used as a synthetic intermediate as well as a reactive agent in organic synthesis to synthesize various organic compounds.

In addition, according to the production method of the present invention, in synthesizing a specific organoboron compound, it can be obtained or purified with higher purity, and the reaction time can be shortened, so that it can be produced more cheaply and simply.

1 is a reaction flow chart in which the manufacturing process of the present invention is divided into stages.
Figure 2 is a picture of the HPLC result of the organic boron compound prepared when using a PdCl2 (dppf) palladium catalyst and a THF solvent.

Hereinafter, a preferred embodiment of the present invention and the physical properties of each component will be described in detail, but this is intended to be explained in detail so that those skilled in the art can easily practice the invention. This does not mean that the technical spirit and scope of the present invention are limited.

An organoboron compound according to an embodiment of the present invention is represented by the following general formula G.

<Formula G>

In the general formula G, R1 to R6 each independently represent hydrogen, an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 16 carbon atoms. R7 and R8 each independently represent either hydrogen or an alkyl group having 1 to 6 carbon atoms, and R7 and R8 may bond to each other to form a ring. R9 represents any one of an alkyl group having 1 to 6 carbon atoms.

In addition, in this specification, as an organoboron compound represented by general formula G, a boronic acid is also included. For boronic acids, R7 and R8 in formula G represent hydrogen. In addition, in the case of boronic acid esters, R7 and R8 in the general formula G are alkyl groups having 1 to 6 carbon atoms.

Specific examples of R1 to R6 substituents include hydrogen, methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, isobutyl group, tert-butyl group, phenyl group, 1-naphthyl group, 2-naphthyl group, respectively. ethyl group, 2-anthryl group, 9-antryl group, pyren-1-yl group, pyren-4-yl group, fluoren-2-yl group and the like. In addition, it can be selected from aryl groups such as phenyl group, 1-naphthyl group, 2-naphthyl group, 2-antryl group, 9-anthryl group, pyren-1-yl group, pyren-4-yl group, fluoren-2-yl group and the like.

Further, as specific examples of the R7 and R8 substituents, hydrogen, methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl group, cyclopentyl group, respectively. , cyclohexyl group, etc. are mentioned. Further, R7 and R8 may be bonded to each other to form a ring, as shown in general formulas G1 to G3 below, for example. Specific examples of the R9 substituent include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, isobutyl, tert-butyl, pentyl, hexyl, cyclopentyl, cyclohexyl and the like. may be, and a methyl group is most preferred.

<Formula G1>

<Formula G2>

<Formula G3>

Specific examples of the organoboron compound represented by the general formula G include organoboron compounds represented by the chemical structural formulas 1 to 9. However, the present invention is not limited to these.

<Chemical structure formula 1>

<Chemical structure formula 2>

<Chemical structure formula 3>

<Chemical structure formula 4>

<Chemical structure formula 5>

<Chemical structure formula 6>

<Chemical structure formula 7>

<Chemical structure formula 8>

<Chemical structure formula 9>

As a method for synthesizing the organoboron compound represented by the general formula G, various reactions can be applied. For example, the organoboron compound represented by the general formula G can be synthesized by carrying out the synthesis reaction shown below. In addition, the synthesis method of the organoboron compound represented by general formula G which is one embodiment of the present invention is not limited to the following synthesis method.

In the present invention, various organic boron compounds were prepared by condensation reaction between a naphthalene derivative having an alkylthio group and an alkenyl boron ester in the presence of a palladium catalyst and a base. A detailed synthesis method for this may refer to the following examples, and FIG. 1 shows a reaction flow chart in which the manufacturing process of the present invention is divided into stages.

The naphthalene derivative having an alkylthio group may further have various substituents, and among them, a halogen group is preferable.

The palladium catalysts include Pd2(dba)3, Pd(PPh3)4, Pd(OAc)2, Pd[P(t-Bu)3]2, PdCl2(PPh3)2, PdCl2((P(o-tolyl) 3) 2, PdCl2 (dppf), PdCl2 (dppe), PdCl2 (dppp), etc. Among them, PdCl2 (dppf) is the most preferable.

In addition, to promote the reaction and increase the yield, phosphine compounds such as PPh3, P-(o-tolyl)3, and PBu3 are used as adducts, or salts such as lithium chloride, lithium bromide, and lithium iodide are used as adducts. can

Since the bond between carbon and boron is quite strong, the metal exchange reaction does not proceed in the absence of a base. Therefore, it is necessary to activate the metal exchange reaction of the boron compound by administering an equivalent or more base to the reaction system.

As the base, hydroxides of alkali metals or alkaline earth metals may be used, and sodium methoxide, cesium acetate, potassium acetate, and the like are preferable.

In the present invention, various alkenyl boron esters can be used in the condensation reaction, and among them, dioxaborolane having a 5-membered ring structure is preferred, and specific examples include Bis (pinacolato) diboron ( ), 2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane ( ), 2-Methoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane ( ) can be used.

When the above reaction is performed, an organic boron compound represented by the following general formula G is produced.

<Formula G>

The description of the substituents of R1 to R8 is the same as described above. That is, in the general formula G, R1 to R6 each independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 16 carbon atoms. R7 and R8 each independently represent either hydrogen or an alkyl group having 1 to 6 carbon atoms, and R7 and R8 may bond to each other to form a ring. R9 represents any one of an alkyl group having 1 to 6 carbon atoms.

In particular, when dioxaborolane having a 5-membered ring structure is used, an organic boron compound represented by the general formula G1 is produced.

<Formula G1>

The organoboron compound of the present invention exhibits strong light emitting characteristics and can be usefully used in the manufacture of organic light emitting diodes (OLEDs).

The process of preparing the compound of the present invention is as follows, focusing on examples. In particular, the present invention is differentiated by using a specific catalyst and solvent for shortened reaction time, high yield and high purity.

Preparation Example 1. Preparation of methyl (naphthalen-1-yl) sulfane

In a round flask, 11.289 g (0.0704 mol) of naphthalene-1-thiol was dissolved in 140 g of acetone, and 3.382 g (0.083 mol) of sodium hydroxide was added at room temperature and stirred to completely dissolve. When sodium hydroxide is completely dissolved, 10 g (0.0704 mol) of iodomethane is added at room temperature and refluxed for 5 hours.

After 5 hours, the reaction solution was distilled under reduced pressure to remove acetone, and after adding 150 ml of dichloromethane and 150 ml of water, the mixture was stirred for 30 minutes and the layers separated. After treating the separated organic layer with magnesium sulfate, drying, filtering, and concentrating the filtrate to remove the solvent, 11.90 g (0.0682 mol) methyl (naphthalen-1-yl) methyl (naphthalene -1-yl)sulfane) was obtained. At this time, the yield is 97.0% and the purity is 96.71%.

On the other hand, when the solvent is changed from acetone to ethanol under the same reaction conditions, the yield is relatively low at 93.2%, but the purity is higher at 99.1%.

Preparation Example 2. Preparation of (2-bromonaphthalen-1-yl) (methyl) sulfane

11.9g (0.0682 mol) of the compound prepared in Preparation Example 1 (Methyl(naphthalen-1-yl)sulfane, hereinafter referred to as 'A') was dissolved in 114g DMF in a round flask. At room temperature, 12.56 g (0.071 mol) of N-bromosuccinimide (NBS) was added and stirred for 30 minutes. After pouring the reaction solution into ice water and adding 300 ml of ethyl acetate, the mixture was stirred for 30 minutes and separated into layers. At this time, the temperature of the reaction solution should be controlled so that it does not rise more than 5 degrees. After drying and filtering the layer-separated organic layer and concentrating the filtrate, a crude liquid product with a purity of 98.2% can be obtained. g (0.0608 mol) yellow oily (2-bromonaphthalen-1-yl) methylsulfane ((2-bromonaphthalen-1-yl) methylsulfane, hereinafter referred to as 'B') was obtained in 88.2% yield (Scheme 1 below) reference).

[Scheme 1]

Example. Synthesis of 4,4,5,5-tetramethyl-2-(1-(methylthio)naphthalen-2-yl)-1,3,2-dioxaborolane

15 g (0.059 mol) of (2-bromonaphthalene-1-yl) (methyl) sulfane prepared in Preparation Example 2 was dissolved in 150 ml of THF solvent while injecting nitrogen into a round flask, and then the reaction solution was heated to -78 ° C. After cooling, a palladium catalyst, a base, and a solvent required for the crosslinking reaction were added to the reaction solution as shown in Table 1 below, and 1.3 times the equivalent of Compound B of Preparation Example 2 was slowly added dropwise.

After injecting all of them, the reaction solution was raised to -30℃ and maintained for 3 hours, then the reaction solution was cooled to -78℃ again for 1 hour, and 2-isopropoxy-4,4,5,5- Tetramethyl-1,3,2-dioxaborolane (2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane, hereinafter referred to as 'PT diborone') was added by 1.4 times the reaction mass. After adding the equivalent amount and reacting for 3 hours, the temperature is raised to room temperature over 1 hour.

Thereafter, the mixture was further reacted at room temperature for 1 hour, followed by reflux reaction for 1 hour, and then cooled to room temperature. 200 ml of ethyl acetate and 300 ml of distilled water were added, and the layers were separated. The organic layer was dried, filtered, and then concentrated under reduced pressure.

When recrystallized from normal heptane after concentration, 4,4,5,5-tetramethyl-2-(1-methylthionaphthalen-2-yl)-1,3,2-dioxaborolein (4 ,4,5,5-tetramethyl-2-(1-(methylthio)naphthalen-2-yl)-1,3,2-dioxaborolane, hereinafter referred to as 'C') product can be obtained (see Scheme 2 below) .

[Scheme 2]

This C compound is an organic boron compound represented by chemical formula 1 of the present invention.

<Chemical structure formula 1>

Various catalysts and solvents were selected to prepare the product (product), and the results of HPLC analysis were summarized in Table 1 and FIG. 2.

The solvent is tetrahydrofuran (THF), dioxane, dichloromethane, ether solvents such as 1,2-dimethoxyethane, aromatic hydrocarbon solvents such as benzene, toluene, and xylene, dimethylformamide, dimethyl sulfoxide ( DMSO), acetonitrile, etc. may be used alone or in combination.

Experimental example Introductory material (boron ester) base catalyst reaction solvent HPLC (%) reaction time introduction impurity 1 impurity 2 product
(water) One PT
Diboron potassium acetate PdCl2 (dppf) toluene 15.88 0.89 3.32 80.81 3 hours 2 PdCl2 (dppf) DMSO 23.91 2.21 7.66 67.55 7 hours 3 PdCl2 (dppf) dioxane 27.32 1.21 10.68 60.12 12 hours 4 PdCl2 (dppf) dioxane 1.81 1.00 0.69 94.88 19 hours 5 PdCl2 (dppf) THF 1.61 1.00 0.90 97.16 6 hours 6 Pd2 (dba)3 dioxane 49.33 0.26 0.96 49.44 12 hours 7 Pd(OAc)2/
P(t-bu)3 dioxane 51.73 - 46.46 1.81 14 hours * PdCl2(dppf): 1,1'-Bis(di-tert-butylphosphino)-ferrocene]palladium(II) Dichloride
* Pd2(dba)3: Tris(dibenzylideneacetone)-dipalladium(0)
* Pd(OAc)2/P(t-bu)3: Palladium(II) Acetate/tris(tert-butyl)phosphine

Experimental Examples 1 to 7 show the results prepared by using different catalysts and reaction solvents under the same inlet (PT diboron) and the same base. PdCl2 (dppf) was selected as the palladium catalyst and THF was the solvent In the case of Experimental Example 5, a product having a synthetic purity of 97.16% was obtained, and when recrystallized with n-heptane, the yield was 80% and the purity was increased to 99.5%. In this case, the purity was the highest compared to other experimental examples, and the reaction time was 6 hours, so it was the most economical synthesis reaction.

Figure 2 is a picture of the HPLC result of the product prepared in the case of Experimental Example 5. The unreacted influent was the least at 1.61% (peak #7, Area%), and the purity of the product was analyzed at 97.16% (peak #9, Area%).

Although the same palladium catalyst PdCl2 (dppf) was used, in the case of using dioxane as a solvent (Experimental Examples 3 and 4), the unreacted influent was relatively large, and the reaction time was 2 to 3 times longer than that of Experimental Example 5. Even if it was increased more than twice, the purity of the product was only 60.12% and 94.88%, respectively.

That is, the case of using THF as a solvent had the advantage of being able to produce a product with high purity more quickly. This is very important because it can reduce the cost in the production process.

Although the present invention has been described in detail with reference to the embodiments above, it is obvious to those skilled in the art that various modifications and variations are possible within the scope of the technical idea of the present invention, and it is natural that such variations and modifications fall within the scope of the appended claims. will be.

Claims (10)

Organoboron compounds represented by the following general formula G
<Formula G>

(However, in the general formula G, R1 to R6 each independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 16 carbon atoms. R7 and R8 are each independently hydrogen and 1 carbon atom represents any one of alkyl groups of 1 to 6. R9 represents any of alkyl groups of 1 to 6 carbon atoms.) The organic boron compound according to claim 1, wherein R7 and R8 are bonded to each other to form a ring. Organic boron compounds represented by the following general formulas G1 to G3
<Formula G1>

<Formula G2>

<Formula G3>

(However, in formulas G1 to G3, R1 to R6 each independently represent hydrogen, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 16 carbon atoms.) Organoboron compound represented by the following chemical formula 1
<Chemical structure formula 1>
As a method for producing an organic boron compound,
Method for producing an organoboron compound represented by the following general formula G by subjecting a naphthalene derivative having an alkylthio group to a condensation reaction with an alkenyl boron ester in the presence of a palladium catalyst and a base
<Formula G>

(However, in the general formula G, R1 to R6 each independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 16 carbon atoms. R7 and R8 are each independently hydrogen and 1 carbon atom represents any one of alkyl groups of 1 to 6. R9 represents any of alkyl groups of 1 to 6 carbon atoms.) The method of claim 5, wherein the solvent available for the reaction is tetrahydrofuran (THF), dioxane, dichloromethane, 1,2-dimethoxyethane, benzene, toluene, xylene, dimethylformamide (DMF), dimethyl Manufacturing method characterized by mixing one or two or more selected from sulfoxide and acetonitrile The method of claim 5, wherein the palladium catalyst is Pd2(dba)3, Pd(PPh3)4, Pd(OAc)2, Pd[P(t-Bu)3]2, PdCl2(PPh3)2, PdCl2(( Any one selected from P(o-tolyl)3)2, PdCl2(dppf), PdCl2(dppe), and PdCl2(dppp), and the base is selected from sodium methoxide, cesium acetate, and potassium acetate. Manufacturing method characterized The method according to claim 5, wherein a phosphine compound of PPh3, P-(o-tolyl)3, or PBu3 is used as an adduct, or a salt of lithium chloride, lithium bromide, or lithium iodide is used as an adduct to accelerate the reaction and increase the yield. Manufacturing method characterized by using as The method of claim 5, wherein the alkenyl boron ester is a 5-membered ring structure dioxaborolane compound Bis (pinacolato) diboron, 2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2- A manufacturing method characterized in that any one is selected from dioxaborolane and 2-Methoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane A light emitting material for an organic light emitting device comprising the organoboron compound of any one of claims 1 to 4