Unnatural α-Amino Acid Synthesized through α-Alkylation of Glycine Derivatives by Diacyl Peroxides

We have developed a protocol for catalyst- and additive-free alpha-alkylation reactions of glycine derivatives with diacyl peroxides, which proceed by a pathway involving addition of alkyl radicals to imine intermediates. The diacyl peroxide substrate acts as both alkylation agent and oxidizing agent, which means it is atom-economical. It was applied to various glycine derivatives, dipeptides, and a 3,4-dihydroquinoxalin-2(1H)-one derivative and could be carried out on a gram scale, indicating its utility for late-stage functionalization.