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(sp 2 )−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 (TMSN 3 ) 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 d 4 ‐methanol (CD 3 OD), leading to the synthesis of d 3 ‐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.