Selectivity in Radical Cation Cycloadditions

1,5-Hydrogen atom transfer of α-iminyl radical cations: a new platform for relay annulation for pyridine derivatives and axially chiral heterobiaryls

“…3,4 For example, the classic McLafferty rearrangement involves the fragmentation of a carbonylcontaining distonic radical cation, which is applied in the structural elucidation using mass spectroscopy. [5][6][7] Moreover, the distonic ions have been recognized as important active intermediates for several organic reactions, which can be exemplied by the well-established Hofmann-Löffler-Freytag reaction which related to the formation of a nitrogen-containing distonic radical cation, 8,9 and the cyclization reactions involving alkene radical cations. [10][11][12][13] Despite these great achievements, the methods for the generation of the distonic ions, the type of these species, and the related synthetic transformations remain limited.…”