Lewis Base Assisted Lithium Brønsted Base Catalysis: A New Entry for Catalytic Asymmetric Synthesis of β<sup>2,2</sup>-Amino Acids

Abstract

A new catalytic system comprising chiral Ag complex and Li aryloxide/bisphosphine oxide is developed for the synthesis of β^2,2-amino acids via direct asymmetric Mannich-type reaction of 4-subsituted isoxazolidin-5-ones. The Mannich adduct is a direct precursor of β-peptidic compounds otherwise difficult to obtain.