Photoredox 1,4-Hydroxysulfonylation of Methylenecyclobutane via Carbon-Radical-Mediated β-Scission of Cyclobutane

作者：Yahong Chen, Xiaoxiao Sun, Shijie Li, Weiwei Huan, Dengke Ma, Yan Zhang · 发表于：Organic Letters · 年份：2026 · DOI：10.1021/acs.orglett.5c05137 · 被引用次数：2 · 研究领域：Radical Photochemical Reactions、Catalytic C–H Functionalization Methods、Sulfur-Based Synthesis Techniques

) bond cleavage is a central challenge in organic synthesis. While radical-mediated β-scission of strained cyclobutanes offers a valuable route to complex molecules, carbon-radical-based ring-opening remains underdeveloped due to the regioselective formation of the cyclobutylcarbinyl radical and high activation barrier issues. Herein, we report a photocatalytic strategy for the 1,4-functionalization of methylenecyclobutanes (MCBs) via a tosyl-radical-initiated cascade. This process involves regioselective addition to the exocyclic double bond, followed by β-scission and a radical-polar crossover, enabling efficient 1,4-hydroxysulfonylation. Mechanistic studies provided evidence of a radical chain process. Key features include a broad substrate scope, a removable tosyl group, controllable three-component reactivity, and the expansion of synthetic methodologies for carbon-radical-mediated cyclobutane ring-opening.