Development of Pyoline Derived Chiral Aminophosphine Ligands for Palladium-Catalyzed Asymmetric Allylic Alkylation

Abstract

A series of chiral aminophosphine ligands with N, N-disubstituted 2-diphenylphosphinoaniline backbone are designed and readily prepared from (R) -2- (methoxymethyl) pyrrolidine or (S) -prolinol. The reactivity and selectivity in the palladium-catalyzed asymmetric allylic alkylation (AAA reaction) of 1, 3-diphenyl-2-propenyl acetate with a dimethyl malonate-BSA-LiOAc system using these chiral ligands are evaluated. Furthermore, chiral fluorous aminophosphine bearing two fluorous ponytails was prepared from (S) -prolinol. Chiral fluorous palladium catalyst from this ligand was easily reused in palladium-catalyzed AAA reaction with good enantioselectivity.