Transition Metal-Free Synthesis of Carbo- and Heterocycles via Reaction of Alkynes with Organylchalcogenides.

This manuscript intends to overview the most recent advances in the synthesis of carbo- and heterocycles through reactions of alkynes with organyl chalcogenides (S, Se, Te) under metal-free conditions. Firstly, the use of electrophilic chalcogenyl halides as a selective reagent for alkyne carbon-carbon triple bond activation will be presented. After that, radical cyclization protocols employing electrochemical oxidative conditions, light-induced photoredox catalysis, or mild oxidants with direct chalcogenyl group installation will be discussed accompanied by the proposed mechanisms.