Visible Light-Induced Alkylation of Malononitrile-Assisted Ketones through Deaminative Couplings

Abstract

The direct alkylation of carbonyl compounds at α & β positions represents a significant challenge. Here, we report a catalyst-free visible light-induced deaminative alkylation that efficiently produces α, β-alkylated malononitrile-assisted ketones. Mechanistic studies suggested an EDA complex is formed by the Katritzky salt and the α & β carbanion of malononitrile-aided ketones, which permits the disruption of C–N bonds and the generation of alkyl radicals. Remarkably, this strategy eliminates the need for metal catalysts, additives, and ligands offering enhanced environmental sustainability and features mild, catalyst-free, and broad functional group tolerance. Our optimized catalyst-free condition under blue LED light yielded regio isomers of malononitrile-assisted ketones in good to excellent yields with diverse electronic properties and substitutions. Implementation of the flow setup to this batch protocol enhanced the efficiency of the reaction, demonstrating robustness and sustainability in organic synthesis.