ChemicalBook CAS DataBase List Isopropenylboronic acid pinacol ester

Isopropenylboronic acid pinacol ester synthesis

3synthesis methods

Product Name:Isopropenylboronic acid pinacol ester
CAS Number:126726-62-3
Molecular formula:C9H17BO2
Molecular Weight:168.04

76-09-5

557-93-7

Boranediamine, 1-chloro-N,N,N',N'-tetrakis(1-methylethyl)-

28049-80-1

126726-62-3

General procedure for the synthesis of isopropenylboronic acid pinacol esters from pinacol, 2-bromopropene and compound (CAS:28049-80-1): 2-bromopropene (89.58 g, 0.741 mol) was dissolved in 750 mL of tetrahydrofuran, and slowly added dropwise from -10 °C to 0 °C with a mixture of bis(diisopropylamino)boron chloride (183 g, 0.74 mol) and lithium metal (10.4 g, 1.5 mol) mixture followed by 110 mL of tetrahydrofuran under strictly controlled reaction conditions. After the dropwise addition, the reaction was maintained at this temperature for 1 h. Then the temperature was raised to 25 °C and the reaction was continued for 5 h. The reaction was completed with the addition of pinacol. Upon completion of the reaction, pinacol (98.8 g), 2,6-di-tert-butyl-4-methylphenol (4.58 g) and 120 mL of tetrahydrofuran were added and the reaction mixture was heated to reflux. Purification by distillation under reduced pressure afforded 82.1 g of colorless transparent liquid isopropenylboronic acid pinacol ester in 66% yield and 99.7% GC purity. Finally, 2,6-di-tert-butyl-4-methylphenol (0.45 g) was added as a stabilizer for long-term storage.

76-09-5 Synthesis

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126726-62-3
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Yield:126726-62-3 66%

Reaction Conditions:

Stage #1:2-bromoprop-1-ene;bis(diisopropylamino)chloroborane with lithium in tetrahydrofuran at -10 - 25; for 6 h;
Stage #2:2,3-dimethyl-2,3-butane diol with 2,6-di-tert-butyl-4-methyl-phenol in tetrahydrofuranReflux;

Steps:

1.2 Synthesis of isopropenylboronic acid pinacol ester:
Dissolve isopropenyl bromide (89.58, 0.7411101) in 75011 ^ tetrahydrofuran, dropwise add bis (diisopropylAmine) boron chloride (183 g, 0.74 mol), lithium metal (10.4 g, 1.5 ml), and 110 mL of tetrahydrofuran were added dropwise a process controlThe reaction temperature was -10 ° C to 0 ° C. After completion of the dropwise addition, the temperature was maintained for 1 hour,The reaction was then continued for 5 hours at 25 ° C.After the completion of the reaction, pinacol (988, 0.83111 01), 2,6-di-tert-butyl-4-methylphenol (4.58) and 1201 tetrahydrofuran were added and the temperature was raised to reflux.Distillation under reduced pressure afforded the colorless transparent liquid isopropenylboronic acid pinacol ester 82.lg, yield 66%, GC: 99.7%2,6-di-tert-butyl-4-methylphenol (0.45 g) was added for long-term storage.

References:

Cangzhou Puri Oriental Technology Co., Ltd.;Leng, Yanguo;Liu, Jinzhou;Feng, Xuemin CN105503923, 2016, A Location in patent:Paragraph 0018

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557-93-7
223 suppliers
$45.10/5g