Copper-Catalyzed Sulfonylation Reaction of NH-Sulfoximines with Aryldiazonium Tetrafluoroborates and Sulfur Dioxide: Formation of N-Sulfonyl Sulfoximines

Abstract

An efficient and practical SO 2 insertion protocol of NH-sulfoximines with aryldiazonium tetrafluoroborates and DABSO toward N-sulfonyl sulfoximines has been developed under mildly basic conditions. This transformation features easy operation, readily available substrates, and mild conditions. A tentative mechanism is proposed, which indicates that the aryldiazonium tetrafluoroborates would be radical donors under standard reaction conditions. The aryl radical produced in situ from diazonium salts would be trapped by SO 2 to generate an arylsulfonyl radical and then undergo further transformation to generate the final N-sulfonyl sulfoximines.

Electrochemical N(sp2)–H/C(sp3)–H cross-coupling reaction between sulfoximines and alkylarenes

“…The NMR data of product 4l is consistent with that reported in the literature. 25 Next, we explored a set of functional groups on the phenyl ring of ethylbenzene, and a weak steric hindrance effect on the reactivity was observed (66% for 4m vs. 76% for 3a ). Besides the MeO group, other alkyloxy groups also showed good reactivity ( 4n–4p ).…”

“…On one hand, product 3g bearing a transformable C–Br bond could be easily modified through a classic Sonogashira cross-coupling reaction, thus introducing an alkynyl unit to the sulfoximine (Scheme 2A). 25 On the other hand, our known, traditional methods for the synthesis of benzylamine 7 were still limited by using benzyl chloride, benzyl alcohol, acetophenone and its derivatives (imine, oxime and hydrazine). 26 An early example reported by Guy and co-workers in 1988 involved the direct C–H amination of alkylbenzene.…”