Photoinduced Carbonyl Coupling Of Aldehydes On Anatase Tio2(101)

Carbonyl coupling of aldehydes is critical to many synthetic processes, including the development of alternative fuels and useful synthetic chemicals. We report a general photoinduced process for carbonyl coupling of aldehydes as a route to ketone synthesis. In contrast to thermal carbonyl coupling of aldehydes with O-2 to ketones via carboxylate-type intermediates at high temperature, carbonyl coupling of aldehydes (CH3CHO, CH3CH2CHO, PhCHO) to produce ketones on anatase-TiO2(101) can be promoted by UV light below room temperature with high efficiency on the Ti-5c sites, while aldehydes can also be decomposed during UV light irradiation. The mechanistic model constructed in this study elucidates the crucial role of TiO2 as a photocatalyst for synthetic reactions and provides a new pathway in conversion of aldehydes to ketones.