Zinc Catalysts for On-Demand Hydrogen Generation and Carbon Dioxide Functionalization

摘要

[Tris(2-pyridylthio)methyl]zinc hydride, [k~3-Tptm]ZnH, is a multifunctional catalyst that is capable of achieving (ⅰ) rapid release of hydrogen by protolytic cleavage of silanes with either water or methanol and (ⅱ) hydrosilylation of aldehydes, ketones, and carbon dioxide. For example, [k~3-Tptm]ZnH catalyzes the release of 3 equivalents of H_2 by methanolysis of phenylsilane, with a turnover number of 10s and a turnover frequency surpassing 10~6 h~(-1) for the first 2 equivalents. Furthermore, [k~3-Tptm]ZnH also catalyzes the formation of triethoxy-silyl formate by hydrosilylation of carbon dioxide with triethoxysilane. Triethoxysilyl formate may be converted into ethyl formate and N,N-dimethylformamide, thereby providing a means for utilizing carbon dioxide as a C_1 feedstock for the synthesis of useful chemicals.