Synthetic organic electrosynthesis has grown in the past few decades by achieving many valuable transformations for synthetic chemists. Although electrocatalysis has been popular for improving selectivity and efficiency in a wide variety of energy-related applications, in the last two decades, there has been much interest in electrocatalysis to develop conceptually novel transformations, selective functionalization, and sustainable reactions. This review discusses recent advances in the combination of electrochemistry and homogeneous transition-metal catalysis for organic synthesis. The enabling transformations, synthetic applications, and mechanistic studies are presented alongside advantages as well as future directions to address the challenges of metal-catalyzed electrosynthesis.

Current methods to achieve transition-metal-catalyzed alkyl carbon–nitrogen (C–N) bond cleavage require the preformation of ammonium, pyridinium, or sulfonamide derivatives from the corresponding alkyl amines. These activated substrates permit C–N bond cleavage, and their resultant intermediates can be intercepted to affect carbon–carbon bond-forming transforms. Here, we report the combination of in situ amine methylation and Ni-catalyzed benzalkyl C–N bond cleavage under reductive conditions. This method permits iterative alkyl group transfer from tertiary amines and demonstrates a deaminative strategy for the construction of Csp3–Csp3 bonds. We demonstrate PO­(OMe)3 (trimethylphosphate) to be a Ni-compatible methylation reagent for the in situ conversion of trialkyl amines into tetraalkylammonium salts. Single, double, and triple benzalkyl group transfers can all be achieved from the appropriately substituted tertiary amines. Transformations developed herein proceed via recurring events: the in situ methylation of tertiary amines by PO­(OMe)3, Ni-catalyzed C–N bond cleavage, and concurrent Csp3–Csp3 bond formation.

We report a strategy to build, cyclize, and excise nitrogen from tertiary amines for the synthesis of polyheterocyclic aromatics. A developed deaminative ring contraction cascade reaction is useful for the synthesis of substituted benzoquinolines.