(Bbpy)(HSO_4)_2无卤素可重复使用 Brnsted 离子液体催化剂用于一锅法多组分合成非对称多氢喹啉衍生物（英文）

One-pot multicomponent synthesis of unsymmetrical polyhydroquinoline derivatives with 1,1'-butylenebispyridinium hydrogen sulfate as an efficient, halogen-free and reusable Brnsted ionic liquid catalyst

1,1'‐Butylenebispyridinium hydrogen sulfate is an efficient, halogen‐free and reusable Brnsted ionic liquid catalyst for the synthesis of ethyl‐4‐aryl/heteryl‐hexahydro‐trimehtyl‐5‐ oxoquino‐line‐3‐carboxylates by the one‐pot condensation of dimedone, aryl/heteryl aldehydes, ethyl aceto‐acetate, and ammonium acetate under solvent‐free conditions. This method has the advantages of high yield, clean reaction, simple methodology, and short reaction time. The ionic liquid can be re‐cycled five times without significant loss of the catalytic activity.