Development of Electrochemical Processes for Nitrene Generation and Transfer

Abstract

An electrochemical strategy for running nitrogen-transfer reactions on chemically inert anode surfaces has been developed. The generation and trapping of highly reactive nitrene-transfer reagents can be accomplished under mild conditions on platinum electrodes. The key factor that accounts for the high levels of chemoselectivity in this process is the phenomenon of overpotential. We have found that molecules that are similar in terms of propensity toward oxidation can be differentiated on the basis of their affinity to a given electrode surface. Thereby, reactive species can be selectively generated in the presence of acceptor molecules of interest. Specifically, a wide range of structurally dissimilar olefins can be transformed into the corresponding aziridines in the presence of N-aminophthalimide. Likewise, nitrene generation in the presence of sulfoxides leads to their chemoselective transformation into the corresponding sulfoximines. In this paper we discuss the underlying mechanistic foundation of these reactions.

Terminal Nitrido and Imido Complexes of the Late Transition Metals

“…[258] Binding of nitrenes to platinum electrode surfaces has been proposed in electrochemical olefin aziridination reactions. [259,260] A (diphosphine)Ni(N 3 ) 2 complex is proposed to form a nitrene-type intermediate upon photolysis that has been shown to react with CO and hydrocarbons. [261] The coinage metals, Cu, Ag, and Au, have also been shown to promote reactions involving nitrenes.…”

Electrochemical strategies for C–H functionalization and C–N bond formation

“…This highlights that reactive species can be selectively generated by maximizing the difference in overpotentials between the substrate and the reagent, thereby avoiding detrimental background reactions. [909][910][911] Likewise, under similar reaction conditions a variety of sulfoxides could be chemoselectively converted into the corresponding sulfoximines. 912 The Moeller group developed a protocol for synthesis of gand d-lactams using O-benzyl hydroxamates or N-phenyl amides.…”

Recent Advances in Constructing Nitrogen‐Containing Heterocycles via Electrochemical Dehydrogenation

“…Although nitrogen radicals and nitrenes are frequently employed as reactive aziridination species for the synthesis of aziridine, the alkenes with steric hindrance are not easy to form the aziridine product (Scheme 42). [69] In 2018, Cheng et al reported an electrochemical aziridination by alkene activation (Scheme 43). [70] The alkene was anodically oxidized to generate an alkene radical cation, which reacted with HfsNH 2 106 to construct the aziridine containing multi-substituted hindered groups 107.…”