Time and Atom Economical Regio- and Chemoselective Radical Cyclization of Unactivated 1,6-Enynes Under Metal- and Oxidant-Free Conditions

Chemistry. 2022 Jul 26;28(42):e202200742. doi: 10.1002/chem.202200742. Epub 2022 Jun 10.

Abstract

We developed time-atom economic regio- and chemoselective sulfonyl radical triggered 5-exo-dig cyclization of unactivated 1,6-enynes with sulfonyl halides under metal, additive-free reaction conditions to achieve highly substituted five-membered heterocyclic compounds. This transformation creates three new bonds, such as C-SO2 , C-C, and active C-I/Br bonds. Importantly, one-pot protocols produce desired products directly from sodium sulfinates and have an additional advantage such as minimising chemical waste, saving time, and simplifying practical aspects compared to existing protocols.

Keywords: metal/oxidant-free; no toxic waste; regio-and chemoselective; time and atom economic; unactivated 1,6-enyne.