Generation Of Alpha-Boryl Radicals And Their Conjugate Addition To Enones: Transition-Metal-Free Alkylation Of Gem-Diborylalkanes

A transition-metal-free method for the alkylation of gem-diborylalkanes with alpha,beta-unsaturated ketones has been developed. It is demonstrated that the alpha-boryl radicals can be generated efficiently from gem-diborylalkanes with the aid of catechol and oxidants. The alpha-boryl radicals formed through such process can be engaged in conjugate addition reaction with alpha,beta-unsaturated ketones. This transformation is a straightforward method for the synthesis of gamma-borylketones.