Electric-field-controlled highly regioselective thiocyanation of N-containing heterocycles

Achieving highly regioselective synthesis in organic chemistry is challenging due to the uncontrollable orientation between reacting partners. External electric fields (EEFs) can influence the reactivity and selectivity of the substrate by causing directional adsorption. However, scalable and efficient techniques for using EEFs as “smart catalysts” have been lacking, hindering their application. In this study, we present a novel method for modifying the regioselectivity of quinoxaline-2(1H)-ones by functionalizing their C7-position using the electric double layer (EDL) theory. This approach led to moderate to good yields of the corresponding C7-thiocyanation products. DFT calculations and control experiments demonstrated that EEFs could reverse the regioselectivity of quinoxaline-2(1H)-ones, allowing the C7-thiocyanation to proceed via a radical reaction mechanism. Additionally, the resulting 7-thiocyano-1-methylquinoxaline-2(1H)-ones exhibited promising AIE properties. Our work showcases a promising strategy for achieving highly regioselective functionalization by aligning the electric field with the desired reaction/bond axis.