Enantioselective Heck‐Type Reaction Catalyzed by tropos‐Pd(II) Complex with Chiraphos Ligand

Abstract
The Pd(II)‐catalyzed enantioselective organoboron‐mediated Heck‐type reaction is shown to proceed under molecular oxygen as an oxidant. The Pd(OAc)2/(S,S)‐chiraphos catalyst gives good yield and the best enantioselectivity. Among the two possible δ‐ and λ‐conformations in equilibrium, this reaction proceeds via the λ‐conformation of chiraphos with the two methyl groups in a diaxial orientation.