Asymmetric Synthesis of Quaternary α-Amino Acids and Their Phosphonate Analogues

Abstract

Asymmetric synthesis of α-amino acids and their phosphonate analogues has received considerable attention due to their diverse biological activities. Quaternary α-amino acids and their phosphonate analogues are often more resistant to chemical and enzymatic degradation and therefore have been targets of various synthetic endeavors. This Focus Review provides a summary of recent approaches to catalytic asymmetric synthesis of quaternary α-amino acids and α-aminophosphonates. Building the building blocks: This review focuses on various recent approaches to the asymmetric synthesis of quaternary α-amino acids and their transition-state analogues, and quaternary α-aminophosphonic acids. The enantio- and diastereoselectivities of these approaches are emphasized, as are the syntheses of intermediates in the preparation of natural products and other bioactive compounds. Pg=protecting group.