Electrochemically Oxidative C–C Bond Cleavage of Alkylarenes for Anilines Synthesis

Abstract

In contrast to the recent breakthrough in electrochemical C–H aminations, the electrochemically oxidative C–N bond formation through a C–C bond cleavage is rarely studied. This work describes an electrochemical C–C amination of alkylarenes for the efficient synthesis of versatile anilines, as well as carbonyl compounds. With the cheap and durable graphite plates as electrodes, and in a simple undivided cell, this protocol is much more economical with the consumption of electricity.

Electrochemical C−C bond cleavage of cyclopropanes towards the synthesis of 1,3-difunctionalized molecules

“…4). 1,3-Oxyfluorination could proceed smoothly when using ether as both oxygen nucleophiles and solvent (49)(50)(51). Cyclic ether such as tetrahydrofuran gave interesting product 49 in 43% yields accompanying with 14% 1,3-difluorination product.…”

“…As a main part of preparative electrosynthesis, anode processes such as C-H functionalization, oxidative coupling, decarboxylation, and olefin functionalization has been developed [39][40][41][42][43][44][45][46][47][48] . However, electrochemical oxidative C−C bond cleavage/functionalization are rarely developed due to the inertness and weak electronic bias of C−C bonds, which are always encumbered by other bonds 8,48,49 . Pioneering work was disclosed by Shono and coworkers who reported anodic oxidation of arylcyclopanes in methanol 50 .…”

Electrochemical C-C Bond Cleavage of Cyclopropanes towards the Synthesis of 1,3-Difunctionalized Molecules

“…Besides alcohols, ethers could also participate in this reaction as oxygen nucleophiles (Figure 3). 1,3-Oxy uorination could proceed smoothly when using ether as both reactant and solvent (48)(49)(50). Cyclic ether such as tetrahydrofuran gave interesting product 48 in 43% yields with etheric ringopening, accompanying with 14% 1,3-di uorination product.…”

Recent progress in C(aryl)–C(alkyl) bond cleavage of alkylarenes

“…The same group also reported an electrochemical C-C amination of alkylarenes 41 for the synthesis of anilines 43 using graphite plates as electrodes in an undivided cell without any external catalyst or oxidant (Scheme 11). 19 The substrate is first oxidized on the anode generating a radical cation which is deprotonated to give a benzyl radical. The benzyl radical further undergoes oxidation forming an intermediate cation which could be nucleophilically attacked by organic azide 42 producing the Schmidt-type intermediate.…”