Studies toward the Photoredox Deoxygenation of Alcohol Derivatives

Alcohols are attractive radical precursors because they are abundant, inexpensive and widely found in nature. However, the development of applicable photoredox deoxygenation methods remains challenging. This work explores new activating groups for photocatalytic deoxygenation. N,O-acetals, methoxymethyl ethers, isobutyrate derivatives, glyoxylates, and formate esters were investigated. Synthetic routes to N,O-acetals, methoxymethyl ethers, and isobutyrate derivatives proved unsuccessful. In contrast, glyoxylate derivatives and benzyl formate were obtained. The reactivity of benzyl formate in the Giese reaction was evaluated under photoredox conditions using different photocatalysts and HAT catalysts, giving the desired product in very low yield in the presence of TBADT under 390 nm irradiation. Ongoing studies are focused on understanding the reaction mechanism and the reactivity of the formyl group under photoredox conditions, aiming to improve the efficiency of this transformation and expand its applicability. Overall, these results provide valuable insights into the design of new selective strategies for photocatalytic alcohol deoxygenation.