[Development of silicon-based Lewis acids and their applications to organic synthesis]

This paper mainly describes the development, synthesis and applications of silicon-based Lewis acids R3SiX [X=I, OTf, NTf2, C(C6F5)Tf-2, etc.] and (R3SiX+MLn). They were principally used to catalyze aldol, allylation, Diels-Alder, ene and Friedel-Crafts reactions. SLAs were used in 0.5 similar to 20 mol%, and the yields of the catalyzed reactions varied from moderate to excellent with the different reactivity of silicon-based Lewis acids. The order of the reactivities is R3SiNTf2>R3SiOTf, (R3SiX+MLn)>R3SiX. The development and applications of chiral SLAs are also reviewed. When chiral trialkylsilyl bis(perfluoromethanesulfonyl)imides were used as catalysts for Diels-Alder reaction of cyclopentadiene and methyl acrylate, ee value of the reaction was up to 54%