Iron-Catalyzed Cyanoalkylation of Glycine Derivatives Promoted by Pyridine-Oxazoline Ligands
Dengfu Lu, Jiajia Cui, Sen Yang, Yuefa Gong
Abstract
An iron-catalyzed C(sp3)–H cyanoalkylation of glycine derivatives with cyclobutanone oxime esters was established for the incorporation of a cyano group into amino acids and peptides. In this reaction, Fe(NTf2)2 and pyridine-oxazoline ligands form highly active catalysts that could simultaneously and selectively activate both substrates. Preliminary mechanistic studies revealed the excellent chemo-selectivity may stem from an in situ formed imine intermediate and a consecutive radical addition. The evidence suggested the interaction between glycinate substrate and the Fe-catalyst has a prominent impact on the catalytic activity, and the catalyst may also activate the imine intermediate as a Lewis acid.