Aerobic Oxidative Synthesis of Formamides from Amines and Bioderived Formyl Surrogates
Xingchao Dai, Yunyan Han, Haijun Jiao, Feng Shi, Jabor Rabeah, Angelika Brückner
Abstract
Abstract 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 (O 2 ) as oxidant on g‐C 3 N 4 supported Cu catalysts. Combined characterization data from EPR, XAFS, XRD and XPS revealed the formation of single CuN 4 sites on supported Cu phen /C 3 N 4 catalysts. EPR spin trapping experiments disclosed ⋅OOH radicals as reactive oxygen species and ⋅NR 1 R 2 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 ⋅NR 1 R 2 and ⋅OOH radicals based on the well‐equilibrated Cu II and Cu I cycle. Our catalyst has much higher activity (TOF) than those based on noble metals.