Synthesis of Tryptamines through a Novel Brønsted Acid Mediated Tandem Reaction Initiated by α-Iminol Rearrangement of Transient 2-Substituted 2-Hydroxycyclobutylimines.

A novel Brønsted acid promoted condensation reaction between a primary aniline and 2-hydroxycyclobutanone provides access to diverse tryptamine derivatives in moderate to good yields. The proposed mechanism involves an α-iminol rearrangement, ring expansion, ring closure, and a depart-and-return rearrangement process. [ABSTRACT FROM AUTHOR]