A kind of hydroboration method of ester

A hydroboration and catalyst technology, applied in the field of hydroboration, can solve the problem that the application of the catalytic amount of a monovalent magnesium compound is not reported, and achieve the effects of wide substrate universality, low toxicity and high yield.

Active Publication Date: 2022-04-19
NANJING FORESTRY UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The application of the existing reported monovalent magnesium compound is stoichiometric, but the application of the catalytic amount of the monovalent magnesium compound has not yet been reported.

Method used

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  • A kind of hydroboration method of ester
  • A kind of hydroboration method of ester
  • A kind of hydroboration method of ester

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] The preparation of the bromide of β-diimine magnesium, the process is as follows:

[0022] In the absence of water and oxygen, 3.27mmol of β-diimine ligand was dissolved in 25mL ether solution in a single-port reaction tube, and 3.92mmol of methylmagnesium bromide was added dropwise to the above solution at -80°C, and reacted at room temperature for 24h. After filtration, the solid was sucked dry, and the filtrate was concentrated to 5 mL to obtain colorless crystals. The mass of solid and crystals was 1.42 g, and the yield was 90%. M.p. 271-273°C. NMR spectrum: 1 HNMR (600MHz, C 6 D. 6 ):δ6.99-6.91(m,6H,Ar-H),4.88(s,1H,CH),3.12(s,4H,OCH 2 CH 3 ),2.65(s,6H,CH 3 ),2.08(s,6H,CH 3 ),1.55(s,6H,NCCH 3 ),0.48(s,6H,OCH 2 CH 3 ) ppm. 13 C{ 1 H}NMR (151MHz, C 6 D. 6 ):δ168.87 (NCCH 3 ), 147.75, 131.57, 129.56, 124.76 (Ar-C), 95.31 (=CH), 65.96 (OCH 2 CH 3 ),23.52(OCH 2 CH 3 ), 21.09 (NCCH 3 ), 18.89, 13.15 (CH 3 ) ppm.

Embodiment 2

[0024] The preparation of the bromide of β-diimine magnesium, the process is as follows:

[0025] In the absence of water and oxygen, 3.27 mmol of β-diimine ligand was dissolved in 25 mL of ether solution in a single-port reaction tube, and 3.60 mmol of methylmagnesium bromide was added dropwise to the above solution at -60°C, and reacted at room temperature for 15 h. After filtration, the solid was sucked dry, and the filtrate was concentrated to 5 mL to obtain colorless crystals. The mass of solid and crystals was 1.46 g, and the yield was 92%. M.p. 271-273°C. NMR spectrum: 1 HNMR (600MHz, C 6 D. 6 ):δ6.99-6.91(m,6H,Ar-H),4.88(s,1H,CH),3.12(s,4H,OCH 2 CH 3 ),2.65(s,6H,CH 3 ),2.08(s,6H,CH 3 ),1.55(s,6H,NCCH 3 ),0.48(s,6H,OCH 2 CH 3 ) ppm. 13 C{ 1 H}NMR (151MHz, C 6 D. 6 ):δ168.87 (NCCH 3), 147.75, 131.57, 129.56, 124.76 (Ar-C), 95.31 (=CH), 65.96 (OCH 2 CH 3 ),23.52(OCH 2 CH 3 ), 21.09 (NCCH 3 ), 18.89, 13.15 (CH 3 ) ppm.

Embodiment 3

[0027] The preparation of the bromide of β-diimine magnesium, the process is as follows:

[0028] In the absence of water and oxygen, 3.27 mmol of β-diimine ligand was dissolved in 25 mL of ether solution in a single-port reaction tube, and 3.27 mmol of methylmagnesium bromide was added dropwise to the above solution at -40°C, and reacted at room temperature for 15 h. After filtration, the solid was sucked dry, and the filtrate was concentrated to 5 mL to obtain colorless crystals. The mass of solid and crystals was 1.49 g, and the yield was 94%. M.p. 271-273°C. NMR spectrum: 1 HNMR (600MHz, C 6 D. 6 ):δ6.99-6.91(m,6H,Ar-H),4.88(s,1H,CH),3.12(s,4H,OCH 2 CH 3 ),2.65(s,6H,CH 3 ),2.08(s,6H,CH 3 ),1.55(s,6H,NCCH 3 ),0.48(s,6H,OCH 2 CH 3 ) ppm. 13 C{ 1 H}NMR (151MHz, C 6 D. 6 ):δ168.87 (NCCH 3 ), 147.75, 131.57, 129.56, 124.76 (Ar-C), 95.31 (=CH), 65.96 (OCH 2 CH 3 ),23.52(OCH 2 CH 3 ), 21.09 (NCCH 3 ), 18.89, 13.15 (CH 3 ) ppm.

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Abstract

The invention discloses a hydroboration method of an ester: under anhydrous and oxygen-free conditions, a β-diimine monovalent magnesium compound is dissolved in a solvent, pinacol borane is added, ester is added, and the reaction is carried out at room temperature for 10 minutes. In the ester hydroboration method of the present invention, the catalyst β-diimine monovalent magnesium compound has high activity for catalyzing the reaction between ester and pinacol borane, wide substrate universality, high reaction catalytic efficiency, and high product yield.

Description

technical field [0001] The invention relates to the technical field of hydroboration, in particular to a method for hydroboration of esters. Background technique [0002] The conversion of esters to alcohols is an important reaction in organic synthesis. There are mainly three methods, one is the reaction of ester with hydride, the other is the reaction of metal catalyst with hydrogen, and the third is the reaction of metal catalyst to catalyze the hydrosilation or hydroboration of ester. Method 1 mainly uses LiAlH 4 and LiBH 4 . This method has obvious disadvantages, such as poor selectivity, easy to fire and so on. Method 2 also has many disadvantages, such as the need for high temperature and high pressure, poor selectivity, etc. X., Wang Y., Liu Y., Wang F., Shi L.; Lee K.H., Lin Z., Lv H., Zhang X. Org. Lett., 2015, 17, 454; Pritchard J., Filonenko G.A.; Putten R.V. , HensenE.J.M., PidkoE.A.Chem.Soc.Rev., 2015, 44, 3808; Biermann U., Friedt W., Lang S., Luhs W., M...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07F3/02C07C249/02C07C251/12C07F5/02B01J31/22
CPCC07C249/02C07C251/12C07F3/003C07F5/025B01J31/1805B01J2531/0213B01J2531/0241B01J2531/22
Inventor 马猛涛罗曼王未凡肖钤徐莉
Owner NANJING FORESTRY UNIV
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