WO2019056280A1

WO2019056280A1 - Method for preparing borate

Info

Publication number: WO2019056280A1
Application number: PCT/CN2017/102815
Authority: WO
Inventors: 薛明强; 颜丹丹; 陈素芳; 洪玉标; 沈琪
Original assignee: 南通纺织丝绸产业技术研究院
Priority date: 2017-09-21
Filing date: 2017-09-21
Publication date: 2019-03-28

Abstract

Disclosed is a method for preparing a borate, comprising the following steps: stirring and mixing evenly a catalyst, a borane, and an aldehyde and reacting to produce a borate; the catalyst being a tris(methylphenyl) rare earth metal complex; and the molecular formula of the tris(methylphenyl) rare earth metal complex can be expressed as: Ln(MeCp)3, Ln being a rare earth metal selected from the lanthanides. The preparation method has extremely high catalytic activity and, at the same time, mild reaction conditions, easy product post-processing, a short reaction time, low catalyst usage, and a great range of substrate applicability and allows industrialized production.

Description

Method for preparing borate ester

Technical field

[0001] The present invention belongs to the field of organic synthesis, and in particular relates to a method for preparing a boric acid ester.

Background technique

[0002] Borate compounds are used in a wide range of applications, not only as polymer additives, gasoline additions, sterilizing agents, flame retardants, but also as lubricant additives and automotive brake fluids. At the same time, boric acid or boric acid ester can be converted into various other functional groups. It is an important reagent in organic synthesis. The research on chiral drugs is gradually deepening. Now, chiral boric acid has been used as a structural unit of pharmaceuticals. Bortezomib, the first approved protease inhibitor for the treatment of multiple myeloma and lymphoma, has a promising future for chiral boric acid or borate. The addition reaction using a carbonyl compound and a borane is the most direct and atom-economic method for synthesizing a borate having different substituents.

[0003] Complexes formed by rare earth ions have unique physiochemical properties and relatively significant magnetic properties under certain conditions. It is important that the stability of the rare earth complex changes irregularly with the change of the radius, and the factors affecting the stability of the complex, in addition to the ionic radius, the change of the metal coordination number in the complex, the steric hindrance effect of the ligand, hydration The degree and valence component also have an important effect on the stability of the complex. Therefore, researchers have changed, modified and enhanced their properties to a large extent by the interaction of rare earth ions with different ligands. For example: By regulating the steric hindrance of the β-diimine group, the homogeneous β-diimine rare earth complex can have unique catalytic properties; for example: The ruthenium complex is miscellaneous in the conductive polymer CN- In PPP, the energy transfer efficiency of the symmetric and asymmetric phenanthrene-β-diketone ruthenium complex is only 0.053%, which is much lower than 1.1% of the β-diketone ruthenium complex of symmetric biphenyl. It is therefore necessary to develop new catalytic systems to efficiently prepare borate esters.

technical problem

[0004] Studies have shown that in the absence of a catalyst, some boranes (e.g., pinacol borane) are less susceptible to borohydride reactions, possibly due to the too low Lewis acidity of such boranes. In the existing catalytic system, the amount of the catalyst is large, generally thousands of grades, the reaction period is long, and the substrate has low universality.

Problem solution Technical solution

[0005] An object of the present invention is to provide a method for preparing a boric acid ester, which is prepared by catalyzing an aldehyde compound and a pinacol borane by a tris(methylene) rare earth metal complex, and the preparation method has high Catalytic activity, mild reaction conditions, easy product post-treatment, short reaction time, low catalyst amount (catalyst can be 0.001% of the molar amount of aldehyde, which is the lowest known catalyst dosage, lower than 0.1% in general) It is used in two orders of magnitude) and has a good substrate application range and can be industrially produced.

[0006] In order to achieve the above object, the technical scheme adopted by the present invention is: a method for preparing a boric acid ester, comprising the steps of: uniformly mixing a catalyst, a borane and an aldehyde, and reacting to prepare a boric acid ester; The structure is as follows:

Wherein Ln represents a rare earth metal selected from the group consisting of lanthanum, cerium, lanthanum, cerium, and lanthanum.

The present invention also discloses the use of a rare earth metal complex as a catalyst for catalyzing the synthesis reaction of an aldehyde and a pinacol borane; the chemical structure of the rare earth metal complex is as follows:

[0009] The molecular formula of the above tri(methylphenyl) rare earth metal complex can be expressed as: Ln(MeCp) ₃ , Ln represents a rare earth metal, one selected from the group consisting of lanthanum, cerium, lanthanum, cerium, and lanthanum. .

[0010] In the above technical solution, the borane is pinacol borane; and the chemical structural formula of the aldehyde is one of the following chemical structural formulas:

[0011]

Wherein R is selected from the group consisting of hydrogen, a hydrazine, a methyl group, a methoxy group, a cyano group, and an alkynyl group.

[0013] In the above technical solution, the catalyst is a tris(methylphenyl) rare earth metal complex, and the amount is 0.0008~0.005<3⁄4, preferably 0.001%, of the molar amount of the aldehyde; the borane is used in an amount of aldehyde molar amount. 1 to 1.2 times; the reaction time is 10 mils! ~ lh; The reaction temperature is room temperature.

[0014] In the above embodiment, the reaction is carried out in an organic solvent, preferably in tetrahydrofuran.

[0015] In the above aspect, after the reaction is completed, the reaction solution is evaporated under reduced pressure to obtain a boronic acid ester.

[0016] The above rare earth metal complex can catalyze the hydroboration reduction reaction of an aldehyde with a pinacol borane to prepare a boric acid ester, and therefore the present invention claims the use of the above rare earth metal complex as a catalyst in synthesizing a boric acid ester; The chemical structure of the rare earth metal complex is as follows:

[]

Wherein Ln represents a rare earth metal selected from the group consisting of ruthenium, osmium, iridium, osmium, and iridium.

[0018] The above technical solutions can be expressed as follows:

[0019]

Beneficial effect

[0021] 1. The amount of the tris(methylphenyl) rare earth complex catalyst of the present invention is only 0.0008~0.005 of the molar amount of aldehyde.

%; The reaction rate is very fast, the reaction temperature is room temperature, and the reaction can reach 99% yield in 10 minutes; the reaction is catalyzed by using a tris(methoxy) rare earth catalyst, which reduces the amount of the catalyst and increases the yield. The daytime is short, the reaction conditions are mild, and the product is easy to handle, highly conforming to the requirements of atomic economic synthesis and green chemical reaction.

[0022] 2. For the first time, the present invention catalyzes the hydroboration of an aldehyde with a tri(methylphenyl) rare earth metal complex. The catalyst has a simple structure and is easy to prepare, and can efficiently catalyze such a reaction.

[0023] 3. The tris(methylphenyl) rare earth metal complex of the present invention has a wide application range to substrates, and is suitable for aldehydes with different steric hindrance and different electronic effects, and the reaction process is simple and controllable, and the yield is high. The product is easy to post-treat and suitable for industrial production, providing more options for the industrial synthesis of boric acid esters.

Embodiments of the invention

Example 1: Sm(MeCp) ₃ catalyzed synthesis of boric acid esters of benzaldehyde and pinacol borane [0025] In an inert gas atmosphere, a catalyst solution of Sm (MeCp) 3 (0.001 mol<3⁄4) in tetrahydrofuran was added to the reaction bottle after dehydration and deoxidation treatment, and then pinacol borane (145.1 μL) was added by a pipette. , 1 mmol), then add benzaldehyde (ΙΟΙ.Ιμί, l mmol) with a pipette. After reacting for 60 min at room temperature, add CDC1 _{3 to} form a solution. The calculated Ή spectrum yield is greater than 99%. Nuclear magnetic data of the product: Ή ΝΜΙ (400 ΜΗζ, CDC13) δ 7.37 - 7.31 (m, 4H), 7.27 (dt, J = 6.1, 3.3 Hz, 1H), 4.94 (s, 2H), 1.27 (s, 12H) . The isolated yield was 95%. Nuclear magnetic data of the isolated product: Ή NMR (400 MHz, CDC1 ₃ ) δ 7.39-7.28 (m, 5H), 4.70 (s, 2H), 1.66 (s, 1H). ¹³ C NMR (101 MHz, CDC1 ₃ ) δ 140.38, 128.10, 127.20, 126.52, 64.92.

Example 2: Y(MeCp) ₃ catalyzed synthesis of boric acid esters of benzaldehyde and pinacol borane

[0027] In an inert gas atmosphere, a catalyst solution of Y(MeCp) 3 (0.005 mol<3⁄4) tetrahydrofuran was added to the reaction bottle after dehydration and deoxidation treatment, and then the pinacol borane (145.1 μ) was added by a pipette. 1 mmol), then benzaldehyde (101. Ιμί, 1 mmol) was added with a pipette, and after reacting for 60 min at room temperature, CDC1 _{3 was} added to prepare a solution. The calculated Ή spectrum yield is greater than 99%, and the nuclear magnetic data of the product is the same as in the first embodiment.

Example 3: Y(MeCp) ₃ catalyzed synthesis of boric acid esters of benzaldehyde and pinacol borane

[0029] A catalyst solution of Y(MeCp) 3 (0.002 mol%) tetrahydrofuran was added to the reaction flask after dehydration and deoxidation under an inert gas atmosphere, and then pinacol borane (145.1 μl) was added by a pipette. Methyl), benzaldehyde (ΙΟΙ.Ιμί, l mmol) was added with a pipette, and after reacting for 60 min at room temperature, CDC1 _{3 was} added to prepare a solution. The calculated Ή spectrum yield is greater than 99%. The nuclear magnetic data of the product is the same as in the first embodiment.

Example 4: Y(MeCp) ₃ catalyzed synthesis of boric acid esters of benzaldehyde and pinacol borane

[0031] A catalyst solution of Y(MeCp) 3 (0.001 mol<3⁄4) tetrahydrofuran was added to the reaction flask after dehydration and deoxidation under an inert gas atmosphere, and then the pinacol borane (145.1 μ) was added by a pipette. 1 mmol), then benzaldehyde (101. Ιμί, 1 mmol) was added with a pipette, and after reacting for 60 min at room temperature, CDC1 _{3 was} added to prepare a solution. The Ή spectrum yield was calculated to be greater than 99%, and the isolated yield was 94%. The nuclear magnetic data of the product is the same as in the first embodiment.

Example 5: Nd(MeCp) ₃ catalyzed synthesis of boric acid esters of benzaldehyde and pinacol borane

[0033] A catalyst solution of Nd(MeCp) ₃ (0.001 mol< _3⁄4 ) tetrahydrofuran was added to the reaction flask after dehydration and deoxidation under an inert gas atmosphere, and then the pinacol borane (145.1 μ) was added by a pipette. 1 mmol), then add benzaldehyde (ΙΟΙ.Ιμί, l mmol) with a pipette. After reacting for 60 min at room temperature, add CDC1 ₃ Into a solution. The Ή spectrum yield was calculated to be greater than 99%, and the isolated yield was 94%. Nuclear magnetic data of the same product as the example

Example 6: Yb(MeCp) ₃ catalyzed synthesis of boric acid esters of benzaldehyde and pinacol borane

[0035] In an inert gas atmosphere, a catalyst solution of Yb(MeCp) ₃ (0.001 mol< _3⁄4 ) tetrahydrofuran was added to the reaction bottle after dehydration and deoxidation treatment, and then the pinacol borane (145.1 μ) was added by a pipette. 1 mmol), then benzaldehyde (101. Ιμί, I mmol) was added with a pipette, and after reacting for 60 min at room temperature, CDC1 _{3 was} added to prepare a solution. The Ή spectrum yield was calculated to be greater than 99%, and the isolated yield was 95%. Nuclear magnetic data of the same product as the example

Example 7: La(MeCp) ₃ catalyzed synthesis of boric acid esters of benzaldehyde and pinacol borane

[0037] A catalyst solution of La(MeCp) 3 (0.002 mol%) tetrahydrofuran was added to the reaction flask after dehydration and deoxidation under an inert gas atmosphere, and then pinacol borane (145.1 μl) was added by a pipette. Methyl), benzaldehyde (101. Ιμί, I mmol) was added with a pipette, and after reacting for 60 min at room temperature, CDC1 _{3 was} added to prepare a solution. The calculated Ή spectrum yield is greater than 99%. The nuclear magnetic data of the product is the same as in the first embodiment.

Example 8: Synthesis of boric acid esters from L _a (MeCp) benzaldehyde and pinacol borane

[0039] Under an inert gas atmosphere, the catalyst La(MeCp) _{3 3} mg (6.7 μηιοΐ) was added to the reaction bottle after dehydration and deoxidation treatment, and 1 mL of tetrahydrofuran was added, and 20 uL was taken with a pipette, and then 0.248 mL of tetrahydrofuran was added. Then use a pipette to take 20 μ! 0.001ηι _Ο 1<3⁄4) into another reaction flask, then add pinacol borane (174 μ 1.2 mmol) with a pipette, then add benzaldehyde with a pipette ( 101.6 μ Immol), after reacting for 1 h at room temperature, a drop was taken from a nuclear magnetic tube with a dropper, and a solution of CDC1 _{3 was} added thereto. The Ή spectrum yield was calculated to be greater than 99%, and the isolated yield was 95%. The nuclear magnetic data of the product is the same as in the first embodiment.

Example 9: La(MeCp) ₃ catalyzed synthesis of boric acid esters of benzaldehyde and pinacol borane

[0041] Under an inert gas atmosphere, the catalyst La(MeCp) _{3 3} mg (6.7 μηιοΐ) was added to the reaction bottle after dehydration and deoxidation treatment, 1 mL of tetrahydrofuran was added, 20 uL was taken with a pipetting gun, and 0.248 mL of tetrahydrofuran was further added. Then, use a pipette to take 20 μ! 0.001ηι _Ο 1<3⁄4) into another reaction flask, then add pinacol borane (174 μ 1.2 mmol) with a pipette, then add benzaldehyde with a pipette. (101.6 μlmmol), after reacting at room temperature for 30 min, a drop was taken from a nuclear magnetic tube with a dropper, and CDC1 _{3 was} added to prepare a solution. The calculated Ή spectrum yield is greater than 99%. The nuclear magnetic data of the product is the same as in the first embodiment.

Example 10: La(MeCp) ₃ catalyzed synthesis of boric acid esters of benzaldehyde and pinacol borane [0043] Under an inert gas atmosphere, the catalyst was added to the reaction bottle after the dehydration and deoxidation treatment of La (MeCp) ₃ 2.7mg (ό.Ομηιοΐ), 1.5mL of tetrahydrofuran, using a pipette to take O. lmL, and then Add ll lmL of tetrahydrofuran, then add 30 L (0.001 mol<3⁄4) to another reaction flask with a pipette, then add pinacol borane (145.1 μL, 1 mmol) with a pipette, and then pipette. Benzoaldehyde (101.6 μL, lmmol) was added to the gun, and after reacting for 60 min at room temperature, a drop was taken up in a nuclear magnetic tube with a dropper, and CDC1 _{3 was} added to prepare a solution. The Ή spectrum yield was calculated to be 99%. The nuclear magnetic data of the product is the same as in the first embodiment.

Example 11: L _a (MeCp) ^ o-methyl benzaldehyde and pinacol borane synthesis borate

[0045] Under an inert gas atmosphere, the catalyst was added to the reaction flask after the dehydration and deoxidation treatment of La(MeCp) ₃ 2.7mg (ό.Ομηιοΐ), 1.5mL of tetrahydrofuran was added, using a pipetting gun to take O. lmL, and then Add ll lmL of tetrahydrofuran, then add 30 L (0.001 mol<3⁄4) to another reaction flask with a pipette, then add pinacol borane (174 μ 1.2 mmol) with a pipette, and then use a pipette. Add o-methylbenzaldehyde (115.6 μlmmol), react at room temperature for 1 h, then pipet a drop into the nucleus tube and add CDC1 _{3 to} form a solution. The Ή spectrum yield was calculated to be 100%. Nuclear magnetic data of the product: Ή NMR (400 MHz, CDC13) δ 7.37 - 7.31 (m, 4H), 7.27 (dt, J = 6.1, 3.3 Hz, 1H), 4.94 (s, 2H), 1.27 (s, 12H) . The isolated yield was 94%. Nuclear magnetic data of the product: Ή NMR (400 MHz, CDC1 ₃ ) δ 7.34-7.20 (m, 4H), 4.68 (s, 2H), 2.35 (s, 3H), 1.69 (s, 1H). ¹³ C NMR (101 MHz, CDC1 ₃ ) δ 138.19, 135.64, 129.86, 127.33, 127.07, 125.58, 63.05, 18.16.

Example 12: L _a (MeCp) synthesis of p-methyl benzaldehyde and pinacol borane to synthesize borate

[0047] Under an inert gas atmosphere, the catalyst La(MeCp) ₃ 4.5 mg (Ιθμηιοΐ) was added to the reaction bottle after dehydration and deoxidation treatment, 3 mL of tetrahydrofuran was added, and then 27 L (0.001 mol<3⁄4) was taken with a pipetting gun. Add to another reaction flask, then add pinacol borane (174 μί, 1.2 mmol) with a pipette, then add o-methylbenzaldehyde (117.9 μί, lmmol) with a pipette and react at room temperature for 1 h. A drop was taken from the nucleus tube and a solution of CDC1 _{3 was} added to form a solution. The calculated Ή spectrum yield is greater than 99%. Nuclear magnetic data of the product: ¹ H NMR (400 MHz, CDC13) δ 7.37 - 7.31 (m, 4H), 7.27 (dt, J = 6.1, 3.3 Hz, 1H), 4.94 (s, 2H), 1.27 (s, 12H ).

Example 13: La(MeCp) ₃ catalyzes the synthesis of borate esters of 2,4,6-trimethylbenzaldehyde and pinacol borane

[0049] Under an inert gas atmosphere, the catalyst La(MeCp) ₃ 2.7 mg (ό.Ομηιοΐ) was added to the reaction bottle after dehydration and deoxidation treatment, 1.5 mL of tetrahydrofuran was added, 0.5 mL was taken from the pipette, and then added. 0.7mL The tetrahydrofuran was then pipetted with 30 L (0.005 mol<3⁄4) into another reaction vial, then pipetitol borane (174 μί, 1.2 mmol) was added using a pipette, and then 2 was added with a pipette. 4,6-trimethylbenzaldehyde (147.5 μί, lmmol), after reacting for 1 h at room temperature, a drop was taken from a nuclear magnetic tube with a dropper, and a solution of CDCl _{3 was} added thereto. The calculated Ή spectrum yield is greater than 99<3⁄4. Nuclear magnetic data of the product: Ή NMR (400 MHz, CDC13) δ 7.37 - 7.31 (m, 4H), 7.27 (dt, J = 6.1, 3.3 Hz, IH), 4.94 (s, 2H), 1.27 (s, 12H) .

Example 14: La(MeCp) ₃ catalyzed synthesis of boric acid esters of o-methoxybenzaldehyde and pinacol borane

[0051] Under an inert gas atmosphere, the catalyst La(MeCp) ₃ 2.7 mg (ό.Ομηιοΐ) was added to the reaction bottle after dehydration and deoxidation treatment, 1.5 mL of tetrahydrofuran was added, and 0.1 mL was taken from the pipette, and then Add ll lmL of tetrahydrofuran, then add 30 μΐ θ.ΟΟΙηιοΙ^) to another reaction flask with a pipette, then add pinacol borane (174 μ 1.2 mmol) with a pipette and add with a pipette. O-methoxybenzaldehyde (120.8 μl mmol), after reacting for 1 h at room temperature, a drop was taken from a nuclear magnetic tube with a dropper, and a solution of CDC1 _{3 was} added thereto. The Ή spectrum yield was calculated to be 100%. Nuclear magnetic data of the product: Ή NMR (400 MHz, CDC13) δ 7.41 (dd, J = 7.5, 0.7 Hz, IH), 7.23 (dd, J = 7.8, 1.4 Hz, IH), 6.95 (t, J = 7.5 Hz , IH), 6.84 (d, J = 8.1 Hz, IH), 4.98 (s, 2H), 3.81 (s, 3H), 1.34 - 1.21 (m, 12H). The isolated yield was 92%. Nuclear magnetic data of the isolated product: Ή NMR (400 MHz, CDCl ₃ ) δ 7.30-7.26 (m, 2H), 6.96-6.88 (m, 2H), 4.69 (s, 2H), 3.87 (s, 3H), 1.23 ( s, IH). ¹³ C NMR (101 MHz, CDCl ₃ ) δ 156.99, 128.51, 128.30, 120.18, 109.73, 61.70, 54.78, 24.3.

Example 15: La(MeCp) ₃ catalyzes the synthesis of borate esters of p-bromobenzaldehyde and pinacol borane

[0053] Under an inert gas atmosphere, the catalyst La(MeCp) ₃ 2.7 mg (ό.Ομηιοΐ) was added to the reaction bottle after dehydration and deoxidation treatment, 1.5 mL of tetrahydrofuran was added, and 0.1 mL was taken from the pipette, and then Add ll lmL of tetrahydrofuran, then add 30 μΐ θ.ΟΟΙηιοΙ^) to another reaction flask with a pipette, then add pinacol borane (132 μ 0.91 mmol) with a pipette, and weigh the p-bromobenzene. Formaldehyde (158 mg, 0.85 mmol), after reacting for 1 h at room temperature, pipet a drop into a nuclear magnetic tube with a dropper, and add CDC1 _{3 to} form a solution. The calculated Ή spectrum yield is 99<3⁄4. Nuclear magnetic data of the product: Ή NMR (400 MHz, CDC13) δ 7.36 (s, IH), 7.26 - 7.18 (m, 3H), 4.89 (s, 2H), 1.27 (s, 12H). The isolated yield was 83 < 3⁄4. Nuclear magnetic data of the product: Ή NMR (400 MHz, CDCl ₃ ) δ 7.47-7.45 (m, 2H), 7.21-7.19 (m, IH), 4.60 (s, 2H), 2.26 (s, IH). 1 ³ C NMR (101 MHz, CDCl ₃ ) δ 139.26, 131.13, 128.11, 120.94.

Example 16: Synthesis of borate esters of L _a (MeCp) ^ p-cyanobenzaldehyde and pinacol borane [0055] Under an inert gas atmosphere, a catalyst La(MeCp) ₃ 2.7 mg (ό.Ομηιοΐ) was added to the reaction bottle after dehydration and deoxidation treatment, 1.5 mL of tetrahydrofuran was added, and then 24.9 L (0.001 mol) was taken with a pipetting gun. <3⁄4) was added to another reaction flask, then pinacol borane (174 μ 1.2 mmol) was added with a pipette, and p-cyanobenzaldehyde (132.7 mg, 1.01 mmol) was weighed and reacted at room temperature for 10 minutes. A pipette was used to draw a drop into the nucleus magnetic tube, and CDC1 _{3 was} added to form a solution. The calculated Ή spectrum yield is greater than 99%. Nuclear magnetic data of the product: Ή NMR (400 MHz, CDC1 ₃ ) δ 7.61 (s, 1H), 7.52 (t, J = 7.0 Hz, 2H), 7.40 (t, J = 7.7 Hz, 1H), 4.90 (s, 2H), 1.22 (s, 12H).

Example 17: La(MeCp) ₃ catalyzes the synthesis of borate esters of isobutyraldehyde and pinacol borane

[0057] Under an inert gas atmosphere, the catalyst La(MeCp) ₃ 2.7 mg (ό.Ομηιοΐ) was added to the reaction bottle after dehydration and deoxidation treatment, 1.5 mL of tetrahydrofuran was added, and then 24.9 L (0.001 mol) was taken with a pipetting gun. <3⁄4) Add to another reaction flask, then add pinacol borane (174 μί, 1.2 mmol) with a pipette, then add cinnamaldehyde (125.9 L, lmmol) with a pipette and react at room temperature for 10 min. A drop was taken from the nucleus tube and a solution of CDC1 _{3 was} added to form a solution. The calculated Ή spectrum yield is greater than 99%.

Example 18: La(MeCp) ₃ catalyzed synthesis of borate esters of pyridine-2-carbaldehyde and pinacol borane

[0059] Under an inert gas atmosphere, a catalyst La(MeCp) ₃ 4.5 mg (Ιθμηιοΐ) was added to the reaction bottle after dehydration and deoxidation treatment, 3 mL of tetrahydrofuran was added, and then 27.1 L (0.001 mol<3⁄4) was taken with a pipetting gun. ) force into the other reaction flask, then add pinacol borane (174 μ 1.2 mmol) with a pipette, then add pyridine-2-carbaldehyde (95.1 μί, lmmol) with a pipette and react for 10 min at room temperature. After that, a drop was taken from the nuclear magnetic tube with a dropper, and CDC1 _{3 was} added to prepare a solution. The calculated Ή spectrum yield is greater than 99%. Nuclear magnetic data of the product: Ή NMR (400 MHz, CDC1 ₃ ) δ 8.60-8.59 (d, / = 5.3 Hz, 1 Η), 7.91-7.88 (t, /= 7.7 Hz, 1 Η), 7.48-7.46 (d, / = 7.9 Hz, 1Η), 7.43-7.40 (m, 1H), 5.08 (s, 2H), 1.30 (s, 12H).

Example 19: Synthesis of borate esters of L _a (MeCp) ortho-alkynbenzaldehyde and pinacol borane

[0061] Under an inert gas atmosphere, the catalyst La(MeCp) ₃ 4.5 mg (Ιθμηιοΐ) was added to the reaction bottle after dehydration and deoxidation treatment, and 3 mL of tetrahydrofuran was added, followed by a pipetting gun to take 27.1 L (0.001 mol<3⁄4). ) force into the other reaction flask, then add pinacol borane (163.7 μί, 1.2 mmol) with a pipette, and weigh the o-alkynylbenzaldehyde (122.3 mg, 0.94 mmol) at room temperature for 10 min. A drop was taken from the nucleus tube and a solution of CDC1 _{3 was} added to form a solution. The calculated Ή spectrum yield is greater than 99%.

Example 20: La(MeCp) ₃ catalyzes the synthesis of borate esters of m-chlorobenzaldehyde and pinacol borane [0063] Under an inert gas atmosphere, a catalyst La(MeCp) ₃ 2.7 mg (6. (Vmol) was added to the reaction bottle after dehydration and deoxidation treatment, 2 mL of tetrahydrofuran was added, and then 24.9 L (0.001 mol) was taken with a pipetting gun. Add <3⁄4) to another reaction flask, add pinacol borane (106.2 μί, 1.2 mmol) with a pipette, and then transfer 145.2 uL of m-chlorobenzaldehyde to room temperature for 60 min. Then take a drop with a dropper. In the nuclear magnetic tube, CDC1 _{3 was} added to form a solution. The calculated Ή spectrum yield was greater than 99%.

Example 21: La(MeCp) ₃ catalyzes the synthesis of boric acid esters from 1,2,3,6-tetrahydrobenzaldehyde and pinacol borane [0065] Under dehydration and deoxidation under an inert gas atmosphere Add 2.5 g (5.6 mol) of catalyst La(MeCp) _{3 to} the reaction flask, add 2 mL of tetrahydrofuran, and then add 35.8 L (0.001 mol<3⁄4) to another reaction flask with a pipette, and then pipette. Adding pinacol borane to the gun (174 μί, 1.2

After adding 1,2,3,6-tetrahydrobenzaldehyde (117.2 uL, 1 mmol) at room temperature for 10 min, a drop was taken from a nuclear magnetic tube with a dropper, and CDC1 _{3 was} added to form a solution. The calculated Ή spectrum yield is greater than 99%.

Claims

Claim

[Claim 1] A method for preparing a boric acid ester, comprising the steps of: uniformly mixing a catalyst, an alkane and an aldehyde, and reacting to prepare a boric acid ester; the chemical structural formula of the catalyst is as follows:

Wherein Ln is selected from the group consisting of ruthenium, osmium, iridium, osmium, and iridium.

[Claim 2] The method for producing a borate ester according to claim 1, wherein the borane is pinacolborane; and the chemical structural formula of the aldehyde is one of the following chemical structural formulas:

/ 一Λ

d

Wherein R is selected from the group consisting of hydrogen, halogen, methyl, methoxy, cyano, alkynyl.

[Claim 3] The method for preparing a boric acid ester according to claim 1, wherein the catalyst is used in an amount of 0.0008 to 0.005 < 3⁄4 of the molar amount of the aldehyde; and the amount of the borane is an aldehyde molar amount. 1 to 1.2 times.

[Claim 4] The method for producing a borate ester according to claim 1, wherein the reaction is carried out in an organic solvent; the reaction is carried out at a temperature of 10 min to 1 h, and the temperature is room temperature.

[Claim 5] The method for producing a boric acid ester according to claim 1, wherein, after the completion of the reaction, the reaction solution is evaporated under reduced pressure to remove the remaining liquid, and n-hexane is added to obtain a boronic acid ester.

[Claim 6] The use of a rare earth metal complex as a catalyst for catalyzing the synthesis of aldehyde and pinacol borane; the chemical structure of the rare earth metal complex is as follows:

[Application 7] The use according to claim 6, wherein the borane is pinacol borane;

The chemical structural formula of the aldehyde is one of the following chemical structural formulas:

Face

Wherein R is selected from the group consisting of hydrogen, saccharin, methyl, methoxy, cyano, alkynyl, and p-dimethylamino.

[Claim 8] The use according to claim 6, wherein the amount of the catalyst is 0.0008 to 0.005 < 3⁄4 of the molar amount of the aldehyde; the amount of the borane is 1 to 1.2 times the molar amount of the aldehyde. The synthesis reaction is carried out in an organic solvent; the daytime of the synthesis reaction is 10 min~lh

, the temperature is room temperature.

[Claim 9] The use of a rare earth metal complex as a catalyst for synthesizing a borate; the chemical structure of the rare earth metal complex is as follows:

[Claim 10] A method for reacting a borane with an aldehyde, comprising the steps of: uniformly mixing a borane with an aldehyde in the presence of a catalyst, and reacting at room temperature for 10 min to 1 h to complete the reaction of borane with an aldehyde. The chemical structure of the catalyst is as follows:

Wherein Ln is selected from the group consisting of ruthenium, osmium, iridium, osmium and iridium; and the amount of the catalyst used is 0.0008 to 0.005 < 3⁄4 of the molar amount of the aldehyde.