Metal-Free Reduction of CO2 to Methoxyborane under Ambient Conditions through Borondiformate Formation.

An abnormal N-heterocyclic carbene (aNHC) based homogeneous catalyst has been used for the reduction of carbon dioxide to methoxyborane in the presence of a range of hydroboranes under ambient conditions and resulted in the highest turnover number of 6000. A catalytically active reaction intermediate, [aNHC-H⋅9BBN(OCOH)2 ] was structurally characterized and authenticated by NMR spectroscopy. A detailed mechanistic cycle of this catalytic process via borondiformate formation has been proposed from tandem experimental and computational experiments.