Conjugated carbonyl moieties are ubiquitous in natural products, pharmaceuticals, and functional materials. The inherent reactivity of carbonyl often necessitates protection and subsequent deprotection steps during multistep syntheses of these compounds. In contrast, benzyl-protected alcohols are safe and frequently used in multistep syntheses due to their robustness under a variety of harsh follow-up reaction conditions. Herein, we report a mild, efficient, and operationally simple method for the synthesis of conjugated carbonyl compounds via visible-light-induced debenzylative oxidation of benzyl ethers under ambient conditions. The protocol utilizes blue LED irradiation in the presence of a catalytic amount of an acridinium-based photocatalyst and DDQ as an electron acceptor, delivering the desired conjugated carbonyl products in excellent yields within a few hours. The methodology exhibits broad substrate scope, high functional group tolerance, and compatibility with complex molecular frameworks, making it highly valuable for late-stage or final-step deprotection in the total synthesis of sensitive or multifunctional molecules.
Bhuyan et al. (Fri,) studied this question.