The Novel Insertion of Imines into a Late-Metal−Carbon σ-Bond: Developing a Palladium-Mediated Route to Polypeptides

Abstract

The palladium complex (bipy)Pd(CH3)NCCH3+OTf- (2; bipy = 2,2‘-bipyridyl, OTf = OSO2CF3) has been found to undergo the novel sequential insertion of carbon monoxide and imine into the metal−carbon bond in a manner directly analogous to that observed in olefin/CO alternating copolymerizations. The structure of the insertion suggests that the unique combination of CO insertion, amide bond formation, carbonyl oxygen chelation, and resonance stabilization of the chelate ring provides the stabilization required for imine insertion to occur.