Üçüncü, MuhammedKarakuş, ErmanKuş, MelihAkpınar, Gürkan ErayAksın Artok, ÖzgeKrause, NorbertKaraca, SılaElmaci, NuranArtok, Levent2017-03-062017-03-062011Üçüncü, M., Karakuş, E., Kuş, M., Akpınar, G.E., Aksın Artok, Ö., Krause, N., Karaca, S., Elmacı, N., and Artok, L. (201). Rhodium- and palladium-catalyzed 1,5-substitution reactions of 2-En-4-yne acetates and carbonates with organoboronic acids. American Chemical Society, 76(15), 5959-5971. doi:10.1021/jo200201r0022-32630022-32630931-75971522-2667http://doi.org/10.1021/jo200201rhttps://hdl.handle.net/11147/4981Two 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.eninfo:eu-repo/semantics/openAccessAcetate groupsDFT calculationOrganoboronic acidsPalladium-catalyzed reactionsRhodium-catalyzedOrganometallicsArticle2-s2.0-7996103804210.1021/jo200201r