om400876j_si_002.cif (27.77 kB)

Nickel-Catalyzed Hydrosilylation of CO2 in the Presence of Et3B for the Synthesis of Formic Acid and Related Formates

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posted on 09.12.2013 by Lucero González-Sebastián, Marcos Flores-Alamo, Juventino J. Garcı́a
The reaction of CO2 with Et3SiH catalyzed by the nickel complex [(dippe)­Ni­(μ-H)]2 (1) afforded the reduction products Et3SiOCH2OSiEt3 (12%), Et3SiOCH3 (3%), and CO, which were characterized by standard spectroscopic methods. Part of the generated CO was found as the complex [(dippe)­Ni­(CO)]2 (2), which was characterized by single-crystal X-ray diffraction. When the same reaction was carried out in the presence of a Lewis acid, such as Et3B, the hydrosilylation of CO2 efficiently proceeded to give the silyl formate (Et3SiOC­(O)­H) in high yields (85–89%), at 80 °C for 1 h. Further reactivity of the silyl formate to yield formic acid, formamides, and alkyl formates was also investigated.