Copper-Catalyzed Radical Reaction of <i>N</i>‑Tosylhydrazones: Stereoselective Synthesis of (<i>E</i>)‑Vinyl Sulfones

A new chemistry of hydrazines that is a copper-catalyzed radical reaction to synthesize vinyl sulfones from readily available N-tosylhydrazones has been described. The protocol provides a novel strategy for the synthesis of various vinyl sulfones including α, β-disubstituted ones and terminal ones. The advantages of the transformation include excellent E stereoselectivity, broad substrate scope, low cost of reagents, and convenient operation. A novel and efficient one-pot synthesis of alkynes from N-tosylhydrazones has been achieved. The studies provide important complementary approaches for the syntheses of vinyl sulfones and alkynes.本研究报道了一种全新的肼类化合物转化策略：以易得的N-对甲苯磺酰腙（N-tosylhydrazones）为原料，通过铜催化的自由基反应合成乙烯基砜（vinyl sulfones）。该方法可为多种乙烯基砜的合成提供全新路径，产物涵盖α,β-二取代乙烯基砜与末端乙烯基砜。该转化反应具备多项优势：优异的E型立体选择性、宽泛的底物适用范围、低廉的试剂成本以及简便的操作流程。本研究同时实现了一种以N-对甲苯磺酰腙为原料的高效一锅法炔烃（alkynes）合成新策略。上述研究为乙烯基砜与炔烃的合成提供了重要的补充途径。