title: Dehydrative Direct C-H Allylation with Allylic Alcohols under [Cp*Co(III)] Catalysis.
abstract: The unique reactivity of [Cp*Co(III)] over [Cp*Rh(III)] was demonstrated. A cationic [Cp*Co(III)] catalyst promoted direct dehydrative C-H allylation with non-activated allyl alcohols, thus giving C2-allylated indoles, pyrrole, and phenyl-pyrazole in good yields, while analogous [Cp*Rh(III)] catalysts were not effective. The high γ-selectivity and C2-selectivity indicated that the reaction proceeded by directing-group-assisted C-H metalation. DFT calculations suggested that the γ-selective substitution reaction proceeded by C-H metalation and insertion of a C-C double bond, with subsequent β-hydroxide elimination. The [Cp*Co(III)] catalyst favored β-hydroxide elimination over β-hydride elimination.
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan).
authors.forename: Yudai
authors.initials: Y
authors.lastname: Suzuki
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan).
authors.forename: Bo
authors.initials: B
authors.lastname: Sun
authors.affiliation: Faculty of Pharmaceutical Sciences, Hoshi University, Ebara, Shinagawa-ku, Tokyo 142-8501 (Japan).|ACT-C (Japan) Science and Technology Agency (Japan).
authors.forename: Ken
authors.initials: K
authors.lastname: Sakata
authors.affiliation: Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-ku, Sapporo 060-0812 (Japan).|Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan).|ACT-C (Japan) Science and Technology Agency (Japan).
authors.forename: Tatsuhiko
authors.initials: T
authors.lastname: Yoshino
authors.affiliation: Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-ku, Sapporo 060-0812 (Japan). smatsuna@pharm.hokudai.ac.jp.|Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan). smatsuna@pharm.hokudai.ac.jp.|ACT-C (Japan) Science and Technology Agency (Japan). smatsuna@pharm.hokudai.ac.jp.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Matsunaga
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan). kanai@mol.f.u-tokyo.ac.jp.
authors.forename: Motomu
authors.initials: M
authors.lastname: Kanai
mesh_terms: D000478:Alkylation; D003035:Cobalt / Q000737:chemistry*; D003681:Dehydration; D007211:Indoles / Q000138:chemical synthesis / Q000737:chemistry; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D020005:Propanols / Q000737:chemistry*; D011720:Pyrazoles / Q000138:chemical synthesis / Q000737:chemistry; D011758:Pyrroles / Q000138:chemical synthesis / Q000737:chemistry; D011789:Quantum Theory
chemical_list: D007211:Indoles; D009942:Organometallic Compounds; D020005:Propanols; D011720:Pyrazoles; D011758:Pyrroles; D003035:Cobalt; C006463:allyl alcohol
keywords: CH activation; cobalt; heterocycles; homogeneous catalysis; transition metals