Metal-free reactions of alkynes via electrophilic iodocarbocyclizations.

Despite attracting tremendous interest over the last few decades, the field of electrophilic cyclizations is still continuously and rapidly developing. Particularly, metal-free reactions that involve the activation of an alkyne using electrophilic halogen sources are powerful tools in the repertoire of synthetic chemists. This brief overview highlights recent progress in C-C bond-forming halocyclizations allowing for the reaction of alkynes with carbon-nucleophiles. Primarily guided by the type of carbon nucleophile, methods are categorized as the addition of arene, malonate, and olefin nucleophiles.