Synthesis of 2,3-Disubstituted Indoles by a Rhodium-Catalyzed Aromatic Amino-Claisen Rearrangement of N-Propargyl Anilines

摘要

Transition-metal-catalyzed intramolecular reactions of heteroatom-tethered substrates are attractive methods for the synthesis of heterocyclic compounds. In particular, regioselective annulations of N-propargyl aniline derivatives by intramolecular hydroarylation are diverse methods for preparing quinoline or indole ring systems (6-endo or 5-exo). Intramolecular hydroarylation is catalyzed by various metal-containing catalysts, and the reactions of N-propargyl anilines give 1,2-dihydroquinolines in a 6-endo manner (path b, Scheme 1).