Electrochemical Ammonium Cation-Assisted Hydropyridylation of Ketone-Activated Alkenes: Experimental and Computational Mechanistic Studies

This work describes an electrochemical ammonium cation enabled hydropyridylation of ketone-activated alkenes under metal- and exogenous reductant free conditions giving access to beta-pyridyl ketones, through dual proton-coupled electron transfer and radical cross-coupling. It features a broad substrate scope and allows a gram-scale synthesis. Ammonium chloride plays various roles in this transformation such as the hydrogen donor, the protonation reagent, and electrolyte. In particular, various experiments and density functional theory (DFT) calculation results show the mechanism of dual proton-coupled electron transfer followed by radical cross-coupling is the preferred pathway.

Automated summary

This work describes an electrochemical method for hydropyridylation of ketone-activated alkenes using ammonium cation, giving access to beta-pyridyl ketones. The method features a broad substrate scope and gram-scale synthesis, with ammonium chloride playing various roles in the transformation. Experiments and DFT calculations confirm the mechanism of dual proton-coupled electron transfer followed by radical cross-coupling as the preferred pathway.