HFIP-Promoted One-Pot Synthesis of Indolines and Pyrrolidines

-heterocycles from readily available amines and alkyl halides in HFIP has been developed. HFIP enables sequential alkylation and cyclization in a one-pot process under acidic conditions. A range of indoline and pyrrolidine derivatives were obtained in moderate to good yields with tolerance toward various functional groups and nitrogen substitution patterns. The synthetic utility of this approach was demonstrated through gram-scale reactions, further transformations of pyrrolidines, and a concise formal synthesis of cephalotaxine.