Domino Assembly of Trifluoromethylated N,O-Heterocycles by the Reaction of Fluorinated α‑Bromoenones with Amino Alcohols

A highly efficient method for the selective synthesis of trifluoromethylated morpholines (4-oxa-1-azabicyclo[4.1.0]­heptanes) and so far unknown 1,4-oxazepanes (2,8-dioxa-5-azabicyclo[5.1.0]­octanes) based on a domino reaction of fluorinated α-bromoenones with β-amino alcohols was elaborated. The assembly of both heterocyclic systems is initiated by an aza-Michael reaction followed by intramolecular cyclization. The conditions for total control of selectivity of the reaction were found