A Versatile Palladium-Mediated Three-Component Reaction for the One-Pot Synthesis of Stereodefined 3-Arylidene-(or 3-Alkenylidene-)tetrahydrofurans

A one-pot reaction between equimolecular amounts of various propargyl alcohols, Michael acceptors, and unsaturated halides (or triflates) in the presence of a palladium(0) catalyst provides a simple and flexible entry into highly substituted 3-arylidene-(or 3-alkenylidene-)tetrahydrofurans. The efficiency of this palladium-mediated three-component reaction has been shown to be strongly influenced by the nature of the catalyst system, and in this regard, a palladium(0) catalyst generated in situ by reduction of PdCl2(PPh3)2 with n-butyllithium has been found particularly effective.