Electrochemical-Oxidation-Induced Site-Selective Intramolecular C(sp³)–H Amination

Abstract

The cross-coupling of C­(sp3)–H and N–H represents one of the most straightforward approaches to construct saturated nitrogen-containing compounds. The additional oxidants or halogenated reagents are generally required in such processes. Herein, we developed an electrochemical oxidative intramolecular C­(sp3)–H amination of amides by employing a carbon rod anode and a platinum plate cathode in an undivided cell under constant-current electrolysis conditions. Tetrabutylammonium acetate was not only employed as an electrolyte, but also can form the intermolecular hydrogen bond with amide and promote cleavage of the N–H bond. The additional oxidants and N-halogenation step can be obviated in this methodology. A variety of benzylic and nonactivated tertiary, secondary, primary C­(sp3)–H amination can be achieved with good yields.

Copper‐Catalyzed N−F Bond Activation for Uniform Intramolecular C−H Amination Yielding Pyrrolidines and Piperidines

“…[4a] Although uniform reaction conditions applicable to both pyrrolidine and piperidine formation are in high demand, there has been no general solution to this problem, except recent exploration of electrochemistry. [17] We have also investigated the intramolecular competition between five-and six-membered-ring formation (Scheme 4). Fors ubstrate 1r with two different benzylic reaction sites, only pyrrolidine formation to 2r was observed.…”

Synthetische Photoelektrochemie

“…Such potentials are less positive than the redox potentials of electron-rich arenes and other functional groups and thus the mild conditions allow excellent redox chemoselectivity. Stahl demonstrated 52 that previously reported electron transfer/proton transfer/electron transfer (ET-PT-ET), 53 proton-coupled electron transfer (PCET) 54 and bromide-mediated electrochemical HLF reactions 55 all failed to convert 47 into product 48, instead yielding a complex mixture of products.…”

Visible Light Mediated C(sp3)‐H Alkenylation of Cyclic Ethers Enabled by Aryl Ketone

“…Very recently, Martin's group reported C(sp 3 )‐H alkylation and arylation of ethers enabled by triplet excited ketones and nickel catalysts . Meanwhile, Lei and coworkers developed excellent new‐stage C(sp 3 )‐H functionalization via electrochemical reaction –. Despite the advances, the scope of organocatalytic α ‐alkoxy alkyl radical generation is still limited.…”