N,N-Disubstituted Allylic Amine Type Aminophosphines with C(aryl)-N(amine) Bond Axial Chirality: Synthesis and Application to Palladium-Catalyzed Asymmetric Allylic Alkylation with Malonates.

Abstract

We designed and synthesized a series of N,N-disubstituted allylic amine type aminophosphines 2, 3 and 4, which are derivatives of chiral ligands 1. Aminophosphines 2-4 (except 2a) exist in C(aryl)-N(amine) bond axial chirality by chiral HPLC analysis. Both enantiomeric isomers of 4b were successfully obtained in an enantiomerically pure form. We demonstrated that 1a, 1b, and 4b can be used as effective chiral ligands for the palladium-catalyzed asymmetric allylic alkylation of 1,3-diphenyl-2-propenyl acetate with malonates in high enantioselectivities (up to 90% ee).