Stereodefined Construction of Trisubstituted Alkenes by Direct Coupling Reaction of Allylating Agents, Alkynes, and Organoboranes

Abstract

Tandem reaction: The Pd-catalyzed three-component coupling reaction of an allylic alcohol, terminal alkyne, and organoborane to give (E)-1-substituted 2-alkyl-1,4-pentadienes, involving geminal allylation and alkylation at the acetylenic terminal carbon, is described. Bis-diene undergoes a similar multicomponent coupling reaction with acetylene and organoborane, involving cyclization of bis-π-allylpalladium, to form trans-allyl pentadienyl cyclic and heterocyclic compounds with excellent regio- and stereoselectivities (see scheme).