Transition‐Metal‐Catalyzed Electrophilic Amination: Application of O‐Benzoylhydroxylamines in the Construction of the C−N Bond

Abstract

Transition-metal-catalyzed electrophilic amination has been developed into a powerful tool for C-N bond construction. So far, O-benzoylhydroxylamines are the most widely used electrophilic aminating reagents. Herein, we summarize the recent advances of O-benzoylhydroxylamines involved in electrophilic amination catalyzed by transition metals. Several pioneering studies and some of the relevant mechanisms are discussed in this review.

Cu-Catalyzed aromatic C–H imidation with N-fluorobenzenesulfonimide: mechanistic details and predictive models

“…Indeed, the use of C–H amination 11–16 methods allow for direct access to the desired C–N functionality in a vast range of hydrocarbons and are cost-effective and environmentally friendly. 17–19 A pertinent example is the recent breakthrough by Nicewicz and coworkers utilizing organic photoredox catalysis to functionalize arene substrates with N-heterocycles and ammonium salts.…”

A Catalyst‐Free Amination of Functional Organolithium Reagents by Flow Chemistry

“…Though the direct amination of organolithiums has been studied, it still remains an ongoing challenge. The direct amination of organolithiums suffers from low yields, formation of by‐products, and limited scope because of the instability and low selectivity of organolithiums ,…”

Copper‐Catalyzed Transsulfinamidation of Sulfinamides as a Key Step in the Preparation of Sulfonamides and Sulfonimidamides

“…In the light of previous work, [2,8,9] the reaction pathway depicted in Scheme 6issuggested:Whenstarting from aCu II salt, the process is initiated by metal reduction to provide aCu I species.Oxidation by O-benzoylhydroxylamine 2 leads to Cu III intermediate A,w hich undergoes ligand exchange with sulfinamide 1 (or 7)togive complex B.Subsequently, B converts to C by metal migration from nitrogen to sulfur. Reductive elimination of C regenerates the Cu I species needed for closing the catalytic cycle and provides as ulfonimidamide,which is stable if N-arylated (to give 8)orlabile if N-unsubstituted (leading to sulfinamides 3 or 5).…”

“…Being guided by literature, [8] O-benzoyl hydroxylmorpholine (2a)w as chosen as amino transfer agent. [9] After an extensive screening and optimization, [10] product 3aa could be obtained in 82 %yield. Ac ombination of CuBr 2 (20 mol %) and PPh 3 (20 mol %) served as catalyst, which as applied in 1,2-dichloroethane (DCE) at 60 8 8Cf or 12 hu nder an argon atmosphere.T he scope of this unprecedented reaction is depicted in Scheme 2.…”