Siloxyallenes revisited. A useful functional intermediate for the synthesis of (Z)-β-branched Morita–Baylis–Hillman type adducts and (Z)-chalcones

Siloxyallenes proved to be a useful functional intermediate in the preparation of (Z)-β-branched Morita–Baylis–Hillman type adducts by the reaction of aldehydes with silylacetylenes or siloxypropynes. Various (Z)-chalcones were stereoselectively synthesized from siloxypropynes via siloxyallenes.