Carbon Dioxide Hydrosilylation Promoted by Cobalt Pincer Complexes

The addition of carbon dioxide to (tBuPNP)­CoH [tBuPNP = 2,6-bis­(di-tert-butylphosphinomethyl)­pyridine] resulted in rapid insertion into the Co–H bond to form the corresponding κ1-formate complex, which has been structurally characterized. Treatment of (tBuPNP)­CoH with PhSiH3 resulted in oxidative addition to form trans-(tBuPNP)­CoH2(SiH2Ph), which undergoes rapid exchange with excess free silane. With 0.5 mol % (tBuPNP)­CoH, the catalytic hydrosilylation of CO2 with PhSiH3 to a mixture of oligomers containing silyl formate, bis­(silyl)­acetyl, and silyl ether subunits has been observed.