Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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Subject: search.filters.subject.Organoboronic acids

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  • Article
    Citation - WoS: 14
    Citation - Scopus: 15
    Rhodium- and Palladium-Catalyzed 1,5-Substitution Reactions of 2-En Acetates and Carbonates With Organoboronic Acids
    (American Chemical Society, 2011) Üçüncü, Muhammed; Karakuş, Erman; Kuş, Melih; Akpınar, Gürkan Eray; Aksın Artok, Özge; Krause, Norbert; Karaca, Sıla; Elmaci, Nuran; Artok, Levent
    Two methods involving the rhodium-catalyzed reaction of 2-en-4-yne acetates and the palladium-catalyzed reaction of 2-en-4-yne carbonates with organoboronic acids were investigated; both afforded exclusively the (E)-configured vinylallenes. The coordinative interaction of the rhodium with the acetate group promoted the δ-elimination of Rh(I)-OAc from the alkenylrhodium intermediate II in both syn and anti modes, with the syn-elimination being the major path. DFT calculations revealed that a conformer of this intermediate (II), which can lead to the (E)-configured vinylallene product via the syn-elimination mode, is energetically the most favorable conformer. The rhodium-catalyzed procedure is not applicable to reactions involving (E)-configured enyne acetates, because the geometry of the alkenylrhodium intermediate that is derived from the corresponding (E)-enyne acetate would not allow such coordinative interaction to occur. The palladium-catalyzed method, which proceeds through formation of the σ-vinylallenylpalladium intermediate, B, is suitable for both the (E)- and (Z)-configured enyne carbonates and appears to have a wider scope for both organoboronic acids and enyne substrates. The palladium-catalyzed reaction of an enantiomerically enriched enyne carbonate proceeded with racemization.
  • Article
    Citation - WoS: 15
    Citation - Scopus: 14
    Rhodium Catalysed Chemo- and Stereoselective Arylative and Alkenylative Cyclisation Reactions of Unsymmetric Diynes Containing a Terminal Alkyne Moiety With Organoboronic Acids
    (Royal Society of Chemistry, 2010) Artok, Levent; Kuş, Melih; Ürer, Bağdagül N.; Türkmen, Gülşah; Aksın Artok, Özge
    Unsymmetric diynes possessing a terminal alkyne moiety reacted with organoboronic acids both chemo- and stereoselectively to afford arylated or alkenylated exocyclic dienes by catalysis from the [Rh(cod)OCH 3] 2 complex. The use of a polar protic solvent, e.g. CH 3OH is required for the success of the process under mild conditions. © 2010 The Royal Society of Chemistry.