Recent Developments of Lewis Acids Catalysis: Lanthanide Catalysts with Long Perfluoro-Chain in Organic Chemistry

Abstract

Recently, the concept of fluorous bi-phasic catalysis (FBC) was introduced as an environmentally benign recyclable process. Numerous nine and long-enough (e.g. perfluorooctyl, C8F17) fluorous ponytails can be employed for fluorous phase immobilization of lanthanide catalysts and to catalyze the Diels-Alder and Friedel-Crafts reactions more efficiently. Meanwhile, Bis(perfluoroalkylsulfonyl)amides of lanthanum, ytterbium, yttrium, and scandium have been described as strong Lewis acids, more powerful catalysts for Diels-Alder acylation, esterification, and Baeyer-Villiger reactions. The key to success is that lanthanide complexes are extremely efficient Lewis acid catalysts by virtue of the highly electron-withdrawing and solubilizing effect of tris(perfluoroalkylsulfonyl)methide and bis(perfluoroalkylsulfonyl)amide without hydrocarbon spacers. On the other hand, it has been reported that a new rare earth perfluorocarboxylate catalyst, the rare earth perfluorooctanoate, showed efficient catalytic activity in the Mannich reaction and the reaction of indole with carbonyl compounds due to the unique surfactivity of the long perfluoro-chain. These catalysts can be prepared, stored and recoveredeasily. In this paper, we will review the application of long perfluoro-chain lanthanide catalysts in a series of organic reactions.