Regioselective Tandem N-Alkylation/C-Acylation of β,γ-Alkynyl α-Imino Esters

A new synthesis of alpha-quaternary alkynyl amino esters and allenoates was developed utilizing umpolung N-addition to beta,gamma-alkynyl alpha-imino esters followed by regioselective acylation. The reaction exhibits broad substrate generality and unique regioselectivity. Moreover, synthesis of alpha-quaternary alkynyl amino esters was also carried out via oxidation of the intermediary enolate followed by alkylation.