Lewis Acid-Mediated Rearrangement of Activated Cyclic Amines: A Facile Synthetic Protocol for the Preparation of Amino Carbonyl Compounds

Ring opening of activated cyclic amines to produce amino carbonyl compounds has been studied in the presence of Lewis acids. Whereas five- and six-membered rings cleave and rearrange via a 1,2-hydride shift, reaction in three- and four-membered rings takes place via a C-C bond migration. In the case of a three-membered ring, a wide variety of Lewis acids proved to be effective for the reaction. Base-induced ring opening of activated alpha,alpha-disubstituted azetidinemethanol and its mechanistic aspects have been studied.