Aluminium-Catalysed Carbonyl-Selective Hydrophosphinylation of α,β-Unsaturated Ketones

Abstract

An aluminium-catalysed carbonyl-selective hydrophosphinylation of α,β-unsaturated ketones is reported herein. Among the synthesised Schiff-base-supported non-precious metal complexes, the aluminium hydride complex C1 exhibited outstanding catalytic activity. In contrast to conventional systems that favour conjugate addition, this catalytic system enables selective addition of dimethyl phosphine oxide to the carbonyl group, thereby altering the inherent regioselectivity of these substrates. Under mild conditions, a wide range of α,β-unsaturated ketones were efficiently converted to the desired products, and double hydrophosphinylation could also be achieved through adjustment of the reagent stoichiometry. DFT calculations provided further insight into the reaction mechanism and support a stepwise aluminium-assisted carbonyl activation pathway involving key Al-O-P intermediates. This work provides an efficient and sustainable strategy for selective C-P bond construction using main-group-metal catalysis.