A Highly Active Manganese Precatalyst for the Hydrosilylation of Ketones and Esters

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• 作者：Tufan K. Mukhopadhyay ; Marco Flores ; Thomas L. Groy ; Ryan J. Trovitch
• 刊名：Journal of the American Chemical Society
• 出版年：2014
• 出版时间：January 22, 2014
• 年：2014
• 卷：136
• 期：3
• 页码：882-885
• 全文大小：333K
• ISSN：1520-5126

文摘

The reduction of (^Ph₂PPrPDI)MnCl₂ allowed the preparation of the formally zerovalent complex, (^Ph₂PPrPDI)Mn, which features a pentadentate bis(imino)pyridine chelate. This complex is a highly active precatalyst for the hydrosilylation of ketones, exhibiting TOFs of up to 76,800 h^鈥? in the absence of solvent. Loadings as low as 0.01 mol % were employed, and (^Ph₂PPrPDI)Mn was found to mediate the atom-efficient utilization of Si鈥揌 bonds to form quaternary silane products. (^Ph₂PPrPDI)Mn was also shown to catalyze the dihydrosilylation of esters following cleavage of the substrate acyl C鈥揙 bond. Electronic structure investigation of (^Ph₂PPrPDI)Mn revealed that this complex possesses an unpaired electron on the metal center, rendering it likely that catalysis takes place following electron transfer to the incoming carbonyl substituent.