Electrocatalytic Proton Borrowing N-Alkylation of Pure Alcohols and Amines

Abstract

Alkylamines are essential intermediates in pharmaceuticals, agrochemicals, and fine chemicals, with annual global consumption reaching up to 6 million tons. Conventional N-alkylation via a hydrogen borrowing pathway from alcohols and amines typically requires harsh conditions, solvents, and additives. Electrochemical strategies offer a more sustainable alternative, but existing methods are largely limited to products with unsaturated bonds and rely on liquid electrolytes. Herein, we reported a proton borrowing pathway-based electrolyzer that enables N-alkylation of pure alcohols and amines under ambient condition. The electrolyzer employs a Pd^δ-/NC cathode, which accelerates proton transfer through the cathodic substrate molecular network and selectively returns protons to the C═N bonds of imines, thereby achieving dibenzylamine production with a Faradaic efficiency of 53%. In addition, the system exhibits robust operational stability, broad substrate tolerance, and sustained alkylamine synthesis at currents up to 200 mA, delivering yield rates as high as 0.21 mmol h^-1 cm^-2 based on electrode area. This work underscores the pivotal role of catalyst design in proton transfer and return processes and provides new insights into decoupling redox processes via electrochemical pathways.