Gold-catalyzed formation of pyrrolo- and indolo-oxazin-1-one derivatives: The key structure of some marine natural products

Taşkaya Aslan, Sultan
Various N-propargylpyrrole and indolecarboxylic acids were efficiently converted into 3,4-dihydropyrrolo- and indolo-oxazin-1-one derivatives by a gold(III)-catalyzed cyclization reaction. Some of the products underwent TFA-catalyzed double bond isomerization and some did not. Cyclization reactions in the presence of alcohol catalyzed by Au(I) resulted in the formation of hemiacetals after cascade reactions.


KIZILYALLI, M; DARRAS, M (Elsevier BV, 1993-12-01)
NaGdP2O7 was synthesized by the solid-state reaction of Gd2O3 with Na2CO3 and 4(NH4)2HPO4 at 650°C. The X-ray powder diffraction data of NaGdP2O7 was indexed in the orthorhombic system with the approximate unit cell dimensions of a = 12.44 , b = 15.00, and c = 15.87 Å and the space group is Pmm2. Analysis of the vibrations of the P2O4-7 ion according to C2v symmetry and approximate band assignments for IR spectra are also reported in this work. The P-O-P band was found to be nonlinear, and some coincidences...
Scalar mesons in radiative phi-meson decays into charged k-meson states
Öztürk, Fahri; Gökalp, Ahmet; Department of Physics (2008)
The role of $f_{0}(980)$ and $a_{0}(980)$ scalar meson intermediate states in the mechanism of radiative $\phi (1020)$ meson decay into two charged $K (494)$ mesons and a photon $\phi\rightarrow K^{+} + K^{-} + \gamma$ is investigated. For the contribution of scalar meson intermediate state two models are considered. In the kaon-loop model, the scalar meson intermediate state couples the final state to the initial $\phi$ meson through a charged kaon-loop. The second model, called no-structure model, consist...
Stereoselective synthesis of optically active cyclopenta[c]pyridines and tetrahydropyridines
SEZER, Serdar; GÜMRÜKÇÜ, Yasemin; BAKIRCI, Irem; Unver, M. Yagiz; Tanyeli, Cihangir (2012-05-15)
The intramolecular Pauson-Khand and ring closing metathesis (RCM) reactions of nitrogen containing chiral enynes and dienes are described. The enyne and diene systems comprised of N-propargylated and N-allylated units are constructed on chiral homoallylic or homopropargylic alcohol backbones, respectively, via S(N)2 and/or modified Mitsunobu reactions. The racemic homoallylic and homopropargylic alcohol derivatives were successfully resolved in high ee (93-99%) by applying chemoenzymatic methods using vario...
Enantioselective synthesis of (S)-2-hydroxypropanone derivatives by benzoylformate decarboxylase catalyzed C-C bond formation
Dunnwald, T; Demir, Ayhan Sıtkı; Siegert, P; Pohl, M; Muller, M (2000-06-01)
Chiral 2-hydroxypropanone derivatives 5a-v, 8a-d, and 10a, b were formed by benzoylformate decarboxylase (BFD) catalyzed C-C bond formation. A donor aldehyde and acetaldehyde as an acceptor were carboligated in aqueous buffer solution with remarkable ease in high chemical yield and good to high optical purity. The substrate range of this thiamin diphosphate dependent enzyme was examined to employ this benzoin condensation type reaction in stereoselective synthesis. The observed dependence of the enantiomeri...
Polystyrene-b-poly(2-vinyl phenacyl pyridinium) salts as photoinitiators for free radical and cationic polymerizations and their photoinduced molecular associations
Taskin, Omer Suat; Erel Göktepe, İrem; Khan, Muhammad Alyaan Ahmed; Pispas, Stergios; Yağcı, Yusuf (Elsevier BV, 2014-07-01)
Polystyrene-b-poly(2-vinyl phenacyl pyridinium hexafluorophosphate) (PS-b-PVPP) was synthesized by reacting polystyrene-b-poly(2-vinyl pyridine) prepared by living anionic polymerization with phenacyl bromide followed by counter anion exchange reaction. The ability of PS-b-PVPP to act as a photoinitiator for both free radical and cationic polymerizations is demonstrated. In the free radical polymerization, the initiation step involves the decay of the excited state of the salt with homolytic bond rupture of...
Citation Formats
S. Taşkaya Aslan and M. BALCI, “Gold-catalyzed formation of pyrrolo- and indolo-oxazin-1-one derivatives: The key structure of some marine natural products,” BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY, pp. 897–905, 2015, Accessed: 00, 2020. [Online]. Available: