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

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.