Iron Complexes of N,C-Chelate Ligands toward Catalytic Hydrosilylation of Ketones.

A family of high-spin iron(II) complexes of N,C-chelate ligands has been prepared and tested toward catalytic ketone reduction using polymethylhydrosiloxane (PMHS). Through this systematic fine-tuning effort, a few highly active catalysts have been identified. The top performer features a 144,000 h-1 turnover frequency and a 80,000 turnover number toward acetophenone reduction by PMHS at room temperature and is compatible with a broad scope of substrates, including the sterically demanding ones. Preliminary studies were conducted to probe the mechanism of the catalysis.