A New Methodology for Synthesis of a Chiral Phosphinocarboxylic Acid through Michael Cyclization−Aldol Tandem Reaction of Chiral α,β,χ,ψ-Unsaturated Bisphosphine Oxide and Application in Palladium-Catalyzed Asymmetric Allylic Alkylation

Upon successive treatment with lithium diisopropylamide and then benzaldehyde, a chiral alpha,beta,psi,omega-unsaturated bisphosphine oxide underwent Michael cyclization-aldol tandem reaction to afford the corresponding endo-alpha,beta-unsaturated cyclic bisphosphine oxides. Sequential stereoselective reduction and Horner-Wadsworth-Emmons olefination gave the corresponding monophosphine oxide. Oxidative conversion of an olefin moiety into a carboxyl group and subsequent deoxygenation of an oxide gave the corresponding chiral phosphinocarboxylic acid, which was successfully applied as a chiral and functionalized monophosphine ligand in a palladium-catalyzed asymmetric allylic alkylation.