(E)-(2-Bromovinyl)diisopropoxyborane1

Akira Suzuki, Hokkaido University, Sapporo, Japan
Shoji Hara, Hokkaido University, Sapporo, Japan


next
Abstract

 
[image]
[119441-89-3]     C8H16BBrO2    (MW 234.93)


InChI = 1/C8H16BBrO2/c1-7(2)11-9(5-6-10)12-8(3)4/h5-8H,1-4H3/b6-5+

InChIKey = OCOSAJWMDGEJAM-AATRIKPKBQ

((E)-vinylation reagent, useful for synthesis of (E)-alkenes, ,-unsaturated ketones, and ,-unsaturated esters)

Physical Data:  bp 73 °C/12 mmHg.

Solubility:  sol ether, THF, CH2Cl2, and CHCl3.

Form Supplied in:  colorless liquid; not available commercially.

Analysis of Reagent Purity:  purity is analyzed by 1H NMR (CDCl3): 1.17 (d, J = 6 Hz, 12H), 4.22–4.56 (m, 2H), 6.37 (d, J = 15 Hz, 1H), 7.06 (d, J = 15 Hz, 1H).

Preparative Methods:  by the bromoboration of acetylene with tribromoborane,2 followed by the addition of isopropanol to the resulting 2-(bromovinyl)dibromoborane (eq 1).3, 4 The reagent is isolated by distillation under nitrogen. Large quantities may be prepared and stored in a refrigerator.
 
[image]
(1)  



Handling, Storage, and Precautions:  moisture sensitive; can be handled in air for a short time but is gradually hydrolyzed to the boronic acid by moisture. It should be stored in a refrigerator under a dry inert gas and transferred by syringe. After prolonged storage it should be distilled under a dry inert gas before use. Sensitive to both base and acid; base treatment causes rapid decomposition by