Supported Cu<sup>II</sup> Single‐Ion Catalyst for Total Carbon Utilization of C<sub>2</sub> and C<sub>3</sub> Biomass‐Based Platform Molecules in the N‐Formylation of Amines
Xingchao Dai, Xinzhi Wang, Jabor Rabeah, Carsten Kreyenschulte, Angelika Brückner, Feng Shi
Abstract
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 C 2 and C 3 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 through the 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 could be amidated to produce formamide. Combined catalyst characterization results revealed preferably single Cu II sites on the surface of Cu/5A, some of which form small clusters, but without direct linking via oxygen bridges. By combining the results of electron paramagnetic resonance (EPR) spin‐trapping, operando attenuated total reflection (ATR) IR spectroscopy and control experiments, it was found that the formation of formamides might involve a HCOOH‐like intermediate and . NHPh radicals, in which the selective formation of . OOH radicals might play a key role.