Supramolecular synthesis of coumarin derivatives catalyzed by a coordination-assembled cage in aqueous solution  

作　　者：Shao-Chuan Li Li-Xuan Cai Li-Peng Zhou Fang Guo Qing-Fu Sun 

机构地区：[1]State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences [2]College of Chemistry, Liaoning University

出　　处：《Science China Chemistry》2019年第6期713-718,共6页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China (21825107, 21601183, 21801241, 21571090);Natural Science Foundation of Fujian Province (2016J05051, 2017J05037);the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB20000000)

摘　　要：A self-assembled Pd_4L_2 cage is employed as a water-soluble molecular flask for the synthesis of functionalized coumarins from a series of salicylaldehyde derivatives and cyanoacetates/malononitrile. The catalytic reaction features mild aqueous conditions and broad substrate scope. Crystal structures of the host-guest complexes for two substrates and one analogous intermediate have been obtained, shedding light on the supramolecular reaction mechanism. Michaelis-Menten kinetic studies were performed in one typical case, revealing that the rate of product formation has been enhanced by over 23-fold in contrast to the background reaction without cage. Moreover, the same reaction catalyzed by a smaller Pd_6L_4 cage gives a mixture of products and much lower yields, suggesting that fine-tuning on the size and symmetry of the cages' cavity is crucial for their applications in supramolecular catalysis.A self-assembled Pd_4L_2 cage is employed as a water-soluble molecular flask for the synthesis of functionalized coumarins from a series of salicylaldehyde derivatives and cyanoacetates/malononitrile. The catalytic reaction features mild aqueous conditions and broad substrate scope. Crystal structures of the host-guest complexes for two substrates and one analogous intermediate have been obtained, shedding light on the supramolecular reaction mechanism. Michaelis-Menten kinetic studies were performed in one typical case, revealing that the rate of product formation has been enhanced by over 23-fold in contrast to the background reaction without cage. Moreover, the same reaction catalyzed by a smaller Pd_6L_4 cage gives a mixture of products and much lower yields, suggesting that fine-tuning on the size and symmetry of the cages' cavity is crucial for their applications in supramolecular catalysis.

关 键 词：coordination-assembly CAGE ENCAPSULATION KNOEVENAGEL condensation 

分 类 号：O6[理学—化学]