Autocatalytic O-Formylation of Alcohols Using CO2

Global drive away from fossil feedstock requires the development of synthetic procedures to enhance the efficiency of CO2 capture and utilization processes using renewable starting materials and catalysts. Here, we report an alternative reaction pathway for the O-formylation of alcohols and bio-alcohols, which affords industrially relevant formate esters. Most products, reported herein, derive their carbon atoms exclusively from renewable sources. The reaction is catalyzed by formic acid, which can also be produced directly from CO2 captured in the reaction. The resulting in situ produced formic acid improves the reaction rate, with each catalyst recycling by simple filtration, product distillation, and reuse of the residual reaction mixture. Hence, CO2 is used as a C1 building block and simultaneously reduced to formic acid, which in turn autocatalytically promotes the reaction.