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. endo 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 (see scheme).