Efficient Palladium-Catalyzed Coupling of Baylis-Hillman Acetates with an Allylstannane

摘要

Acetates of Baylis-Hillman adducts derived from ethyl acrylate, methyl vinyl ketone, and acrylonitrile were coupled with allyltributylstannane using Pd(PPh_3)_4 or Pd(dba)_2 as the catalyst at room temperature to afford the corresponding trisubstituted alka-1,5-dienes in good to high yields.The Baylis-Hillman reaction is an important carbon-carbon bond-forming reaction affording highly functional-ized alkenes.1 Baylis-Hillman adducts and their acetates are valuable synthetic intermediates for the synthesis of a variety of heterocycles. They are also used as intermediates for the preparation of trisubstituted alkenes bearing various functional groups by nucleophilic substitutionor a cross-coupling reaction with organometallics using palladium and rhodium as a catalyst or alkyl halides using zinc7 and trialkylindium.8 Organic compounds containing a terminal C=C bond moiety are important for the construction of target molecules, such as by metathesis.