Formate-Catalyzed Selective Reduction of Carbon Dioxide to Formate Products Using Hydrosilanes

Abstract

Formate salts were found to be active and selective homogeneous catalysts for the hydrosilylation of CO2. Counter cations and solvents strongly affected their catalytic activity. The use of toluene as a solvent rendered the recyclable catalyst system. Lewis basic polar solvents such as N-methylpyrrolidone and dimethyl sulfoxide significantly accelerated the reaction. The turnover number approached up to 1800. Analyses of the Fourier-transform infrared spectroscopy and in situ 1H nuclear magnetic resonance spectra suggested that the catalysis proceeds via electron donation from the solvent to hydrosilane, thereby accelerating the hydride transfer step.