Free radical transformations are widely used in organic chemistry. The generation of carbon-centered radicals most often occurs from the corresponding halogenated derivatives. Recently, the processes of formation of C-centered radicals by homolytic cleavage of the C-S bond have attracted considerable attention of researchers. The generation of such intermediates directly from thiols is rather problematic due to the side process of hydrogen transfer.
Researchers from the Zelinsky Institute of Organic Chemistry carried out an efficient process of generating C-centered alkyl radicals from thiols, as well as involved them in the reaction with alkenes. The success is due to the in situ generation of zinc thiolates, which are the direct precursors of radicals. This makes it possible to exclude the presence of free thiol in the reaction mixture and, as a consequence, the side process of the hydrogen atom transfer to the resulting radical does not occur.
Vyacheslav I. Supranovich, Vitalij V. Levin, Vladimir A. Kokorekin, Alexander D. Dilman Generation of Alkyl Radicals from Thiols via Zinc Thiolates: Application for the Synthesis of gem-Difluorostyrenes Adv. Synth. Catal., 2021, accepted manuscript. DOI: 10.1002/adsc.202100088.