The photocatalytic selective 1,2-hydroxyacylmethylation of 1,3-dienes with sulfur ylides as the source of alkyl radicals†
The utilization of the zwitterionic properties of sulfur ylides has long been known to be a versatile strategy used in a wide range of chemical transformations for the construction of different-sized rings. By contrast, their use in radical synthetic chemistry has been significantly limited due to a dearth of general activation methods. Herein, a convenient visible-light-driven proton-coupled electron transfer strategy that enables sulfur ylides to decompose into their corresponding α-carbonyl carbon radicals is reported. Utilizing this strategy, highly selective 1,2-hydroxyacylmethylation between 1,3-dienes, sulfur ylides, and water under the action of photoredox catalysis is achieved (>40 examples are shown). Preliminary mechanistic studies and theoretical calculations shed light on the mechanism and the origin of the regioselectivity.