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

A synthetic method to prepare spiro[4,n]alkyl[b]indoles (n = 4–6) efficiently that relies on the gold(I) and Bronsted acid mediated spirocyclization of 2- and 3-indolyl-tethered 1,4-enyne acetates ...