Synthesis of Indoles through C2–C3 Bond Formation Using Lawesson’s Reagent

Amidophenylglyoxylic esters react with Lawesson's reagent at elevated temperatures, leading to the formation of a diverse array of indole derivatives. This methodology demonstrates broad substrate tolerance and utilizes readily available starting materials. Moreover, this synthetic route is metal-free and environmentally compatible. The scalability of this approach is evidenced by successful gram-scale reactions, highlighting its potential industrial applicability. Furthermore, the resulting products are amenable to further modifications, thereby expanding the potential applications of this synthetic strategy.