Copper-Catalyzed Conjugate Addition of Diboron Reagents to α,β-Unsaturated Amides: Highly Reactive Copper-1,2-Bis(diphenylphosphino)benzene Catalyst System

An efficient copper catalyst system for the beta-boration of alpha,beta-unsaturated amides has been developed. Copper-bisphosphine complexes with small bite angles generate efficient catalyst systems for the successful conjugate addition of bis(pinacolato)diboron to a variety alpha,beta-unsaturated amides under mild conditions. This method was utilized in the formal synthesis of (S)-fluoxetine.