Synthesis of 2,3-substituted indole

For this come back, I propose you a titanium mediated synthesis of indole (intramolecular McMurry reaction) described some years ago by A. Fürstner starting from disubstituted aromatic rings, ketones in one hand and carboxamides in the other hand. The reaction is conducted in DME (dimethoxyethane) with TiCl3 and Zinc dust to provide different indole ring with good yield.

Organic Syntheses, Coll. Vol. 10, p.382 (2004); Vol. 76, p.142 (1999).