Highly Enantioselective Synthesis of Polycyclic Dihydroisoquinolinones via NHC-Catalyzed [4 + 2] Annulations

J Org Chem. 2024 Oct 4;89(19):14135-14140. doi: 10.1021/acs.joc.4c01529. Epub 2024 Sep 13.

Abstract

The NHC-catalyzed enantioselective [4 + 2] annulation of 9H-fluorene-1-carbaldenydes with cyclic imines was successfully developed. A series of optically enriched polycyclic dihydroisoquinolinones were synthesized in moderate to excellent yields with good to excellent enantioselectivities. In addition, this efficient method could also be amenable to the synthesis of spirocyclic compounds by using isatin-derived ketimines as the electrophiles.