Dehydrative Direct C-H Allylation with Allylic Alcohols under [Cp*Co-III] Catalysis

作者：Suzuki, Yudai; Sun, Bo; Sakata, Ken; Yoshino, Tatsuhiko; Matsunaga, Shigeki^*; Kanai, Motomu

来源：Angewandte Chemie - International Edition, 2015, 54(34): 9944-9947.

DOI：10.1002/anie.201503704

• C-H activation
• cobalt
• heterocycles
• homogeneous catalysis
• transition metals

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 phenylpyrazole in good yields, while analogous [Cp*Rh-III] catalysts were not effective. The high g-selectivity and C2-selectivity indicated that the reaction proceeded by directing-group-assisted C-H metalation. DFT calculations suggested that the gamma-selective substitution reaction proceeded by C-H metalation and insertion of a C-C double bond, with subsequent beta-hydroxide elimination. The [Cp*Co-III] catalyst favored beta-hydroxide elimination over beta-hydride elimination.

• 出版日期2015-8-17