HAT‐Mediated Electrochemical C(sp²)−H Alkoxylation of Pyrido[1,2‐a]pyrimidin‐4‐ones with Aliphatic Alcohols

Abstract

A direct alkoxylation of the electron‐deficient olefinic C(sp2)−H bond in pyrido[1,2‐a]pyrimidin‐4‐ones using aliphatic alcohols has been developed under transition metal and external chemical oxidant‐free electrochemical conditions. Azidotrimethylsilane (TMSN3) is utilized as a hydrogen atom transfer (HAT) reagent to enable the homolytic cleavage of the unfunctionalized O−H bond in alcohols, thereby generating the electrophilic alkoxy radicals. Moreover, the effectiveness of this method is demonstrated with d4‐methanol (CD3OD), leading to the synthesis of d3‐methoxylated N‐heterocycles in good yields under sustainable conditions. The proposed mechanism, based on alkoxy or trideuteromethoxy radicals, is substantiated by control experiments and cyclic voltammetry (CV) studies.