Electrochemical Oxidative Clean Halogenation Using HX/NaX with Hydrogen Evolution

Summary Organic halides (R-X) are prevalent structural motifs in pharmaceutically molecules and key building blocks for the synthesis of fine chemicals. Although there are numbers of routes available in literatures for the synthesis of organic halides, the reported methods often require stoichiometric additives or oxidants, metal catalysts, leaving groups or directing group, and/or toxic halogenating agents. In addition, the necessity of employing different, often tailor-made, catalytic systems for each type of substrates also limits the applicability of these methods. Herein, we report a clean halogenation by electrochemical oxidation with NaX/HX. A series of organic halides were prepared under a metal catalyst- and exogenous-oxidant-free reaction conditions. It is worth noting that this reaction has a broad substrate scope, various heteroarenes, arenes, alkenes, alkynes, even aliphatic hydrocarbons could be applied. Most importantly, the reaction could also be performed on a 200 mmol scale with the same efficiency (86%, 50.9 g pure product).