Gold and Brønsted Acid Catalyzed Spirocyclization of 2- and 3-Indolyl-Tethered 1,4-Enyne Acetates to Spiro[4,]alkyl[]indoles.

A synthetic method to prepare spiro[4,]alkyl[]indoles ( = 4-6) efficiently that relies on the gold(I) and Brønsted acid mediated spirocyclization of 2- and 3-indolyl-tethered 1,4-enyne acetates at room temperature and open to air is described.