Stereoselective Photoredox Catalyzed (3+3) Dipolar Cycloaddition of Nitrone with Aryl Cyclopropane

作者：Yao Xu, Haixiang Gao, Chengkai Pan, Yue Shi, Chi Zhang, Genping Huang, Chao Feng · 发表于：Angewandte Chemie · 年份：2023 · DOI：10.1002/ange.202310671 · 被引用次数：10 · 研究领域：Cyclopropane Reaction Mechanisms、Sulfur-Based Synthesis Techniques、Catalytic C–H Functionalization Methods

Abstract By resorting to the principle of remote activation, we herein demonstrate the first photoredox catalyzed (3+3) dipolar cycloaddition of nitrones with aryl cyclopropanes. Key to the fidelity of the reaction resides in a facile manner of substrate activation by single‐electron transfer (SET) oxidation with photoredox catalysis, and the reaction takes place through a stepwise cascade encompassing a three‐electron‐type nucleophilic substitution triggered cyclopropane ring‐opening and a diastereoselective 6‐endo‐ trig radical cyclization manifold. The reaction proceeds under mild conditions with excellent regio‐ and stereoselectivity, nicely complementing the well‐developed Lewis acid catalyzed cycloaddition of donor‐acceptor cyclopropanes. Other merits of the protocol include wide scope of aryl cyclopropanes with diversified substitution patterns and good functional‐group compatibility. A mechanism involving an aryl radical cation promoted remote activation mode was also proposed and supported by mechanistic experiments.