• Title/Summary/Keyword: Stereoselective

검색결과 182건 처리시간 0.022초

Stereoselective Palladium Catalyzed Cyclizations of Enediyne Compounds

  • 오창호;임철윤;정형훈;정승현
    • Bulletin of the Korean Chemical Society
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    • 제20권6호
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    • pp.643-647
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    • 1999

  • Hydropalladium carboxylates, formed from π-allylpalladium chloride dimer plus carboxylic acids, have been shown to catalyze cyclization of structurally diverse enediynes to form the corresponding six- or five-membered rings depending upon the reaction conditions. Some enediynes having an Oxygen linker in an appropriate position under the similar condition yielded the corresponding cyclopropanation products in highly stereoselective manner. A study using deuterated formic acid has proven that the alkylpalladium intermediates formed in our conditions were reduced by the pendant formate ligand. The dienediyne 10 yielded only the tricyclic product 12 in 67% yield, although it was expected to frrm the cyclic product 11. All these cyclizations seemed to occur via the corresponding alkylpalladium intermediates I. which could proceed to the corresponding cyclic products depending on the reaction conditions and the substrates. The study using ceuterated formic acid could provide an important information to understand the present cyclization mechanism. Overall the present study could play an important role in developing new synthetic methodologies for constructing complex polycyclic compounds.

  • https://doi.org/10.5012/bkcs.1999.20.6.643 인용 PDF