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Dehydrative Direct CH Allylation with Allylic Alcohols under [Cp*Co III ] Catalysis
Author(s) -
Suzuki Yudai,
Sun Bo,
Sakata Ken,
Yoshino Tatsuhiko,
Matsunaga Shigeki,
Kanai Motomu
Publication year - 2015
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201503704
Subject(s) - chemistry , metalation , catalysis , medicinal chemistry , reactivity (psychology) , selectivity , allylic rearrangement , hydroxide , cationic polymerization , pyrrole , hydride , organic chemistry , hydrogen , medicine , alternative medicine , pathology
The unique reactivity of [Cp*Co III ] over [Cp*Rh III ] was demonstrated. A cationic [Cp*Co III ] catalyst promoted direct dehydrative CH 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 CH metalation. DFT calculations suggested that the γ‐selective substitution reaction proceeded by CH metalation and insertion of a CC double bond, with subsequent β‐hydroxide elimination. The [Cp*Co III ] catalyst favored β‐hydroxide elimination over β‐hydride elimination.