Supported CuII Single Ion Catalyst for Total-carbon Utilization of C2-C3 Biomass-based Platform Molecules in N-Formylation of Amines.

Abstract

The shift from fossil carbon sources to renewable ones is vital for developing sustainable chemical processes to produce valuable chemicals. In this work, value-added formamides were synthesized in good yields by the reaction of amines with C2-C3 biomass-based platform molecules such as glycolic acid, 1,3-dihydroxyacetone and glyceraldehyde. These feedstocks were selectively converted by catalysts based on Cu-containing zeolite 5A via in-situ formation of carbonyl-containing intermediates. To the best of our knowledge, this is the first example in which all the carbon atoms in biomass-based feedstocks might be amidated to result in the formamide product. Combined catalyst characterization results revealed preferably single CuII sites on the surface of Cu/5A, some of which form small clusters, but without direct linkage via oxygen bridges. By combing the results of EPR (electron paramagnetic resonance) spin-trapping, operando ATR-IR (attenuated total reflection infrared) spectroscopy and control experiments, it has been found that the formation of formamides might involve a HCOOH-like intermediate and •NHPh radicals, where the selective formation of •OOH radicals might play a key role.