Photocatalytic selective 1,2-hydroxyacylmethylation of 1,3-dienes with sulfur ylides as source of alkyl radicals

Exploration of the zwitterionic property of sulfur ylides has long been known as a flexible strategy in a wide range of chemical transformations for different ring-sized construction. By contrast, their use in radical synthetic chemistry has been significantly limited due to dearth of general activation methods. Herein, a convenient strategy of visible light-driven proton-coupled electron transfer was reported to enable sulfur ylides to decompose into the corresponding α-carbonyl carbon radicals. With this method, a highly selective 1,2-hydroxyacylmethylation between 1,3-dienes, sulfur ylides and water under photoredox catalysis is thus achieved (>40 examples). Preliminary mechanistic studies and theoretical calculations shed light on the mechanism and the origin of regioselectivity.