Gold-Catalyzed Intramolecular Indole/Alkyne Cyclization Cascades through a Heterolytic Fragmentation: 1,5-Indole Migration and Allenylation

Gold-catalyzed intramolecular reactions of 3-alkynyl-bearing indoles with diol groups lead to the formation of highly functionalized 3-allenylindoles with high efficiency. The reaction likely proceeds by a new gold-catalyzed cascade cyclization/heterolytic fragmentation/elimination reactions, which results in 1,5-indole migration and C-3 allenylation of indole moiety.