Synthesis of δ-bromo γ,δ-unsaturated carbonyl compounds via palladium-catalyzed bromoalkylation of alkynoates

J Org Chem. 2012 Feb 17;77(4):2029-34. doi: 10.1021/jo202416h. Epub 2012 Feb 6.

Abstract

Palladium-catalyzed regio- and stereoselective intermolecular tandem reaction of electron-deficient alkynes, CuBr(2), and allylic alcohol to synthesize δ-bromo-γ,δ-unsaturated carbonyls was developed. A mechanism involving bromopalladation of alkyne, followed by insertion of allylic alcohol and allylic hydrogen shift, is proposed. The shift of allylic hydrogen is the rate-limiting step in this reaction.