Diversity-Oriented Synthesis of Heterocycles: Al(OTf)3-Promoted Cascade Cyclization and Ionic Hydrogenation.

An efficient and facile method has been developed for the diversity-oriented synthesis of heterocycles. Hexahydrophenoxazines, tetrahydroquinolines, indolines, hexahydrocarbazoles, and lactones were conducted via Al(OTf)3-promoted cascade cyclization and ionic hydrogenation. Furthermore, this protocol was utilized to smoothly prepare piracetam and its key intermediate as well.