Synthesis of 1-Aminoindenes through Aza-Prins-Type Cyclization.

An acid-catalyzed aza-Prins-type endo cyclization of 2-alkenylbenzaldehydes with BocNH2 or aniline derivatives through in situ generation of iminium intermediates has been developed, and various 1-aminoindene derivatives were readily obtained. The first catalytic asymmetric variant of the present reaction has also been demonstrated.