119441-89-3

(E)-(2-Bromovinyl)diisopropoxyborane is used as a (E)-vinylation reagent, useful for synthesis of (E)-alkenes, α,β-unsaturated ketones, and α,β-unsaturated esters).

(E)-(2-Bromovinyl)diisopropoxyborane is synthesized by the bromoboration of acetylene with tribromoborane, followed by the addition of isopropanol to the resulting 2-(bromovinyl)dibromoborane (eq 1). The reagent is isolated by distillation under nitrogen. Large quantities may be prepared and stored in a refrigerator.    

(E)-(2-Bromovinyl)diisopropoxyborane 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.

(E)-(2-Bromovinyl)diisopropoxyborane is moisture sensitive; can be handled in air for a short time but is gradually hydrolyzed to the boronic acid by moisture. Sensitive to both base and acid; base treatment causes rapid decomposition by β-elimination.