Heteroannulation of arynes with N-aryl-α-aminoketones for the synthesis of unsymmetrical N-aryl-2,3-disubstituted indoles: an aryne twist of Bischler-Mohlau indole synthesis

Reaction of 2-(trimethylsilyl)aryl triflates 1 with N-aryl-alpha-aminoketones 2 afforded N-aryl-2,3-disubstituted indoles in good to excellent yields with complete control of the substitution patterns. This methodology allowed for the first time a one-step synthesis of unsymmetrical 2,3-dialkyl substituted indoles in a regiospecific manner.