10.1021/ja4116346.s004 Tufan K. Mukhopadhyay Tufan K. Mukhopadhyay Marco Flores Marco Flores Thomas L. Groy Thomas L. Groy Ryan J. Trovitch Ryan J. Trovitch A Highly Active Manganese Precatalyst for the Hydrosilylation of Ketones and Esters American Chemical Society 2014 Active Manganese Precatalyst Electronic structure investigation PPr Ph form quaternary silane products TOF carbonyl substituent metal center PDI electron transfer atom-efficient utilization bond 2014-01-22 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/A_Highly_Active_Manganese_Precatalyst_for_the_Hydrosilylation_of_Ketones_and_Esters/2330101 The reduction of (<sup>Ph<sub>2</sub>PPr</sup>PDI)­MnCl<sub>2</sub> allowed the preparation of the formally zerovalent complex, (<sup>Ph<sub>2</sub>PPr</sup>PDI)­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<sup>–1</sup> in the absence of solvent. Loadings as low as 0.01 mol % were employed, and (<sup>Ph<sub>2</sub>PPr</sup>PDI)Mn was found to mediate the atom-efficient utilization of Si–H bonds to form quaternary silane products. (<sup>Ph<sub>2</sub>PPr</sup>PDI)Mn was also shown to catalyze the dihydrosilylation of esters following cleavage of the substrate acyl C–O bond. Electronic structure investigation of (<sup>Ph<sub>2</sub>PPr</sup>PDI)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.