Unveiling the Reactivity of Part Per Million Levels of Cobalt‐Salen Complexes in Hydrosilylation of Ketones

Abstract

AbstractA series of air‐stable cobalt(III)salen complexes Co‐1 to Co‐4 have been synthesized and employed in the hydrosilylation of ketones. Notably, the most intricately tailored Co‐3 pre‐catalyst exhibited exceptional catalytic activity under mild reaction conditions. The developed catalytic hydrosilylation protocol proceeded with an unusual ppm level (5 ppm) catalyst loading of Co‐3 and achieved a maximum turnover number (TON) of 200,000. A wide variety of aromatic, aliphatic, and heterocyclic ketones encompassing both electron‐donating and electron‐withdrawing substituents were successfully transformed into the desired silyl ethers or secondary alcohols in moderate to excellent yields.