title: Direct C(sp3)-H Cross Coupling Enabled by Catalytic Generation of Chlorine Radicals.
abstract: Here we report the development of a C(sp3)-H cross-coupling platform enabled by the catalytic generation of chlorine radicals by nickel and photoredox catalysis. Aryl chlorides serve as both cross-coupling partners and the chlorine radical source for the α-oxy C(sp3)-H arylation of cyclic and acyclic ethers. Mechanistic studies suggest that photolysis of a Ni(III) aryl chloride intermediate, generated by photoredox-mediated single-electron oxidation, leads to elimination of a chlorine radical in what amounts to the sequential capture of two photons. Arylations of a benzylic C(sp3)-H bond of toluene and a completely unactivated C(sp3)-H bond of cyclohexane demonstrate the broad implications of this manifold for accomplishing numerous C(sp3)-H bond functionalizations under exceptionally mild conditions.
authors.affiliation: Department of Chemistry, Princeton University , Princeton, New Jersey 08544, United States.
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Shields
authors.affiliation: Department of Chemistry, Princeton University , Princeton, New Jersey 08544, United States.
authors.forename: Abigail G
authors.initials: AG
authors.lastname: Doyle
mesh_terms: D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D002713:Chlorine / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry*
chemical_list: D005609:Free Radicals; D002713:Chlorine; D002244:Carbon; D006859:Hydrogen