Palladium-Catalyzed Three-Component Coupling of 1,1-Dibromoalkenes, Vinylzinc Chloride, and Soft Nucleophiles: One-Pot Synthesis of 1,3-Disubstituted Allenes.

The three-component coupling reaction of 1,1-dibromoalkenes 1, vinylzinc chloride 2, and carbon soft nucleophiles 3 was realized in the presence of the catalytic palladium/Xantphos species, and 1,3-disubstituted allenic products 5 were obtained in yields of up to 77%. The successive two palladium-catalyzed processes, namely the cross-coupling reaction and the allylic substitution, assembled 5 from the easily accessible starting compounds.