Stereoselective synthesis of optically active cyclopenta[c]pyridines and tetrahydropyridines

SEZER, Serdar
Unver, M. Yagiz
Tanyeli, Cihangir
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 various lipases such as PS-C II, Lipozyme, and CAL-B. Each enantiomerically enriched enyne afforded the most conformationally stable diastereomeric cyclopenta[c]pyridine ring system as the sole product, whereas enantiomerically enriched dienes gave tetrahydropyridine derivatives as a result of intramolecular Pauson-Khand and RCM reactions, respectively.


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Conducting copolymers were synthesized via the electrochemical oxidation of pyrrole (Py) in the presence of the monomer 1,12-bis(2-thienyl)-2,5,8,11-tetraoxadodecane (1). The presence of monomer I in the electrolytic solution greatly changed the CV behavior of Py during its potensiodynamic polymerization. The electroactivity of poly(I-co-Py) increased with the increasing amount of I in the comonomer mixture. Copolymer films were prepared via constant potential electrolysis in an electrolytic solution contai...
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Covalent Dimers of 1,3-Diphenylisobenzofuran for Singlet Fission: Synthesis and Electrochemistry
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The synthesis of covalent dimers in which two 1,3-diphenylisobenzofuran units are connected through one phenyl substituent on each is reported. In three of the dimers, the subunits are linked directly, and in three others, they are linked via an alkane chain. A seventh new compound in which two 1,3-diphenylisobenzofuran units share a phenyl substituent is also described. These materials are needed for investigations of the singlet fission process, which promises to increase the efficiency of solar cells. Th...
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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.
Deuterium kinetic isotope effects in the gas-phase S N2 reactions of solvated fluoride ions with methyl halides
Kato, Shuji; Hacaloğlu, Jale; Davico, Gustavo E.; DePuy, Charles H.; Bierbaum, Veronica M. (2004-11-11)
Rate constants and deuterium kinetic isotope effects (KIEs) are measured for gas-phase nucleophilic substitution (S(N)2) reactions of solvated fluoride ions of F-(methanol) + CH3X (X = Br, I), F-(isopropyl alcohol) + CH3I, and F-(hydrogen fluoride) + CH3I at 300 K. The isotope effects are determined as the rate constant ratio k(H)/k(D) for specifically deuterated reactants, that is, methanol (CH3OH, CD3OH, CH3OD, and CD3OD), isopropyl alcohol (i-C3H7OH and i-C3H7OD), hydrogen fluoride (HF and DF), and methy...
Citation Formats
S. SEZER, Y. GÜMRÜKÇÜ, I. BAKIRCI, M. Y. Unver, and C. Tanyeli, “Stereoselective synthesis of optically active cyclopenta[c]pyridines and tetrahydropyridines,” TETRAHEDRON-ASYMMETRY, pp. 662–669, 2012, Accessed: 00, 2020. [Online]. Available: