A series of unsymmetrical pyridine-bridged pincer-type imidazolium salts have been synthesized and demonstrated as highly active catalyst for the cycloaddition of carbon dioxide with a broad range of terminal epoxides without organic solvent,and co-catalyst.It has been found that the performance of catalyst deeply depends on the remotely structural feature bearing pyridine ring.In addition,bulky internal epoxide is also efficiently converted to the desired product.The robustness of the catalytic system was shown by recycling the catalyst over seven consecutive times without significant loss of activity.