Angewandte Chemie International Edition · 2019 · 101 citations · 60 references
Natural SciencesChemistryCatalysisGreen ChemistryOrganic ChemistryPhotocatalysisPhotochemical SynthesisPhotochemistryRadical ReactionsFunctionalizationHeterocycle FunctionalizationPhotochemical FunctionalizationPyridine ChemistryPyridine Synthesis
Abstract The photocatalyzed ortho ‐selective migration on a pyridyl ring has been achieved for the site‐selective trifluoromethylative pyridylation of unactivated alkenes. The overall process is initiated by the selective addition of a CF 3 radical to the alkene to provide a nucleophilic alkyl radical intermediate, which enables an intramolecular endo addition exclusively to the ortho ‐position of the pyridinium salt. Both secondary and tertiary alkyl radicals are well‐suited for addition to the C2‐position of pyridinium salts to ultimately provide synthetically valuable C2‐fluoroalkyl functionalized pyridines. Moreover, the method was successfully applied to the reaction with P‐centered radicals. The utility of this transformation was further demonstrated by the late‐stage functionalization of complex bioactive molecules.
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Laura J. Allen, Pablo J. Cabrera, Melissa Lee et al. · Journal of the American Chemical Society · 2014 · 406 citations · Full text