Primary Alcohols via Nickel Pentacarboxycyclopentadienyl Diamide–Catalyzed Hydrosilylation of Terminal Epoxides

The efficient and regioselective hydrosilylation of epoxides co-catalyzed by a pentacarboxycyclopentadienyl (PCCP) diamide nickel complex and Lewis acid is reported. This method allows for the reductive opening of terminal, monosubstituted epoxides to form unbranched, primary alcohols. A screen of diamide PCCP ligands revealed a correlation of steric demand and regioselectivity, with smaller ligands being optimal, while the addition of Lewis acid enabled efficient reactions at room temperature. A range of substrates including both terminal and non-terminal epoxides are shown to work, and a mechanistic rationale is provided. This work represents the first use of a PCCP derivative as a ligand for transition metal catalysis.