Regioselective Rearrangement of Nitrogen- and Carbon-Centered Radical Intermediates in the Hofmann-Loffler-Freytag Reaction.

ABSTRACT: The Hofmann-Löffler-Freytag (HLF) reaction serves as a late-stage functionalization technique for generating pyrrolidine heterocyclic ring systems. Contemporary HLF protocols utilize in situ halogenated sulfonamides as precursors in the radical-mediated rearrangement cycle. Despite its well-established reaction mechanism, experiments toward the detection of radical intermediates using EPR techniques have only recently been attempted. However, the obtained spectra lack the distinct features of the N-centered radicals expected for the employed reactants. This paper presents phenylbutylnitrone spin-trapped C-centered and N-centered radicals, generated via light irradiation from N-halogen-tosyl-sulfonamide derivatives and detected using EPR spectroscopy. NMR spectroscopy and DFT calculations a

SUBMITTER: Zubcic G 

PROVIDER: S-EPMC11000220 | biostudies-literature | 2024 Apr

REPOSITORIES: biostudies-literature