Organocatalytic Reaction of α‐(3‐Isoindolinonyl) propargylic Alcohols With 3‐Aminoindoles for Construction of δ‐Carbolines

An efficient TFA ‐catalyzed cascade transformation of α‐(3‐isoindolinonyl)propargylic alcohols with 3‐aminoindoles has been developed for the de novo synthesis of multisubstituted δ‐carbolines. This one‐pot protocol integrates a series of sequential steps, including dehydration, 1,4‐addition, isomerization, Claisen rearrangement, aromatization, and ring‐opening, to deliver δ‐carbolines derivatives in a highly efficient manner. Notably, this work not only provides a powerful strategy for the de novo construction of these complex polycyclic scaffolds but also significantly expands the synthetic utility of α‐(3‐isoindolinonyl)propargylic alcohols.