Aerobic Oxidative Synthesis of Formamides from Amines and Bioderived Formyl Surrogates.

Herein we present a new strategy for the oxidative synthesis of formamides from various types of amines and bioderived formyl sources (DHA, GLA and GLCA) and molecular oxygen (O2) as oxidant on g-C3N4 supported Cu catalysts. Combined characterization data from EPR, XAFS, XRD and XPS revealed the formation of single CuN4 sites on supported Cu(phen)2/C3N4 catalyst. EPR spin trapping experiments disclosed ●OOH radicals as reactive oxygen species and ●NR1R2 radicals being responsible for the initial C-C bond cleavage. Control experiments and DFT calculations showed that the successive C-C bond cleavage in DHA proceeds via a reaction mechanism co-mediated by ●NR1R2 and ●OOH radicals based on the well-equilibrated CuII and CuI cycle. Our system has much higher activity (TOF) than those using noble metals.