“…Previously, we have developed several efficient and mild systems catalyzed by acidic ionic liquids to generate carbocations from alcohols, which can react with sulfonamide, amide, carbamate, aromatic amine, olefins, thiols et al to produce corresponding products [24–28] . Ionic liquids exhibit high thermal and chemical stability, negligible vapor pressure, easy recyclability, tunable properties and could be used as environmental catalysts for the reaction by introducing different functionalized groups [29–33] . On the other hand, dimethyl carbonate (DMC) is recognized as a green solvent for fast biodegradability, low toxicity, mild odor, low evaporation rate, low density and good environmental compatibility [34,35] and it has been used in several reactions, such as rearrangement reaction, [36] Diels‐Alder reaction, [37] insertion reaction, [38] olefin metathesis transformations, [39] asymmetric hydrogenation, [40] oxidation [41] …”