Facile Asymmetric Synthesis of α,α-Disubstituted Amino Acid Derivatives with Gold Redox Catalysis Using a Chiral Auxiliary

A facile asymmetric synthesis of α,α-disubstituted amino acid derivatives was achieved via gold redox catalysis. The in situ formed aryl gold(III) served as the key intermediate toward alkyne activation. Sequential vinyl gold(III) addition to diazonium salts, followed by the gold(III) reductive elimination, yielded the α-diazo amides. The asymmetric synthesis was achieved with a selected oxazolidinone auxiliary, providing high stereoselectivity (d.r. >20:1, 99% ee). Simple derivatization afforded α,α-disubstituted peptides with good yield and good functional group diversity.