In situ generation of ion-paired chiral ligands: rapid identification of the optimal ligand for palladium-catalyzed asymmetric allylation

Abstract

A method for the in situ generation of ion-paired chiral ligands from simple salts of ammonium phosphines and chiral Brønsted acids under phase-transfer conditions is established. The exploitation of this method in combinatorial ligand screening has enabled the rapid identification of the optimal ion-paired chiral ligand for the palladium-catalyzed asymmetric allylic alkylation of benzo[b]thiophen-2(3H)-ones.