Organocatalyzed Hydroacylation of Enones by Photosensitization of Acyl Silanes

A mild protocol for hydroacylation of enones through photosensitization of acyl silanes with thioxanthone under blue light (455 nm) irradiation is reported. A Brønsted acid is used as a cocatalyst in the reaction. The versatility of the method is demonstrated through inter‐ and intramolecular hydroacylation reaction. The hydroacylation product is applied for synthesizing an anti‐HCV agent. Mechanistic insights are also provided through control experiments. An organocatalytic protocol for hydroacylation of enones with a catalytic system comprising thioxanthone and Brønsted acid is reported. The method is applicable to both inter‐ and intramolecular hydroacylation reactions. Synthetic derivatizations to access an anti‐HCV agent and preliminary mechanistic studies are also discussed.