Palladium-Catalyzed Intramolecular Dearomatization of Indoles via Decarboxylative Alkynyl Termination

A highly
diastereoselective dearomatization of indoles via palladium-catalyzed
decarboxylative alkynyl termination was developed. This protocol provides
dissimilar tetracyclic and tetrasubstituted indoline scaffolds bearing
congested stereocenters, which led to operationally simple conditions,
short time, and broad substrate scope. Additionally, this reaction
system could be scaled to gram quantities in a satisfactory yield
and diastereoselectivity.