Calcium(II)-Catalyzed Reductive Amination of Biomass-Derived Keto Acids to Functionalized Lactams under Solvent-Free Conditions

Direct access to the polyfluorinated lactams through Ca(NTf2)2 catalyzed by either the reductive amination of biomass-derived keto acids with amines or the reductive amination of amino acids with carbonyl derivatives under solvent-free conditions is realized. The two versatile protocols display chemospecificity and good substrate tolerance to deliver five- to eight-membered lactams with diverse functionality and substitution patterns. The robustness of the methodology is further demonstrated by subsequent application in the late-stage functionalization of drug molecules.