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1.
Ruthenium(II) tris(2,2′-bipyridine) complexes show interesting photochemical properties1. Complexes containing substituents in the 4-and 4′-position of the 2,2′-bipyridine ligand have recently been used in systems which are aimed at the conversion and storage of solar energy2,3. 2,2′-Bipyridine has a long history as a metal-chelating agent4. The use of 4,4′-disubstituted bipyridines as metal-chelating agents so far has been restricted probably because the reported syntheses of these compounds are rather laborious and the yields are low or moderate5–8. 相似文献
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《Tetrahedron: Asymmetry》1999,10(11):2119-2127
A general synthetic approach to 2,3-unsaturated glycosides connecting with nucleosides involving Ferrier rearrangements of glycals is discussed. The new compounds were identified by NMR and MS (HRFAB+). The hydroxylation of the resulting 2,3-unsaturated glycosides was completed using OsO4 to give 5′-O-glycosylnucleosides in good yield. 相似文献
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5,5′-Dialkyl-6,6′-dichloro-2,2′-bipyridines were synthesized starting from 3-substituted 2-chloro-6-iodopyridines using Pd-catalyzed coupling conditions. 6-Alkyl-3,5-dichloro-2H-1,4-oxazin-2-ones were excellent precursors for the synthesis of these functionalized 2-iodo-6-chloropyridines. 相似文献
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T. P. Glushenko V. I. Goncharov A. V. Aksenov 《Chemistry of Heterocyclic Compounds》2008,44(3):314-315
A method has been developed for the synthesis of 1′-R-1′,4′-dihydro-2,3′-biquinolin-4′-ones based on the interaction of quinaldine
with N-alkyl-N-formylanthranilic acid methyl esters under the conditions of the Claisen condensation.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 409–410, March 2008. 相似文献
9.
Sz. Lehel G. Horváth I. Boros P. Mikecz T. Márián L. Trón 《Journal of Radioanalytical and Nuclear Chemistry》2000,245(2):399-401
5-Deoxy-5-[18F]fluoro-adenosine was synthesised by nucleophilic radiofluorination reactions of 5-deoxy-5-haloadenosines. The homogeneous isotope exchange in 5-deoxy-5-fluoro-adenosine was also investigated. The conversion of these reactions was found to be rather low and depends on the strength of the halogen-carbon bond: 0.248% for chloride-, 0.488% for bromide- and 1.070% for iodide-derivative; there was no reaction observed in the case of fluoro-compound. 相似文献
10.
Values of the condensed phase standard (p = 0.1 MPa) molar enthalpy of formation for 2′- and 4′-methylacetophenones were derived from the standard molar energies of combustion, in oxygen, at T = 298.15 K, measured by static bomb combustion calorimetry. The values of the standard molar enthalpy of vaporization, at T = 298.15 K, were measured by Calvet microcalorimetry. Combining these two values, the following enthalpies of formation in the gas phase, at T = 298.15 K, were then derived: 2′-methylacetophenone, –(115.7 ± 2.4) kJ · mol−1, and 4′-methylacetophenone, –(122.6 ± 2.4) kJ · mol−1. Substituent effects are discussed in terms of stability and compared with other similar compounds. The value of the standard molar enthalpy of formation for 3′-methylacetophenone was estimated from isomerization schemes. 相似文献
11.
《Tetrahedron letters》1988,29(13):1521-1524
Reductive cyclization of the title compound to the corresponding dinaphthocycloöctatriene is a facile process. The dinaphthocycloöctatriene does not undergo ring inversion on the NMR time scale, even at elevated temperatures. 相似文献
12.
《Tetrahedron: Asymmetry》1999,10(15):2975-2981
The racemization behavior of a series of atropisomeric 8,8′-dialkyl-1,1′-biisoquinolines, in which methyl, ethyl, and isopropyl groups are introduced for enhancing the transannular steric hindrance, is reported. Contrary to prior expectations, their configurational stability was inversely proportional to the steric size of the alkyl groups. 相似文献
13.
《Tetrahedron: Asymmetry》2001,12(4):533-534
(±)-3,3′4,4′-Tetramethyl-1,1′-diphosphaferrocene-2-carboxylic acid 1 was resolved via diastereomeric salts with brucine. The (R)-absolute configuration of (+)-1 was determined by X-ray crystallography. 相似文献
14.
A. G. Mustafin R. R. Gataullin I. B. Abdrakhmanov L. V. Spirikhin G. A. Tolstikov 《Russian Chemical Bulletin》1998,47(10):2007-2008
A modified synthesis of 3′-azido-3′-deoxythymidine starting fromD-xylose is proposed.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2062–2063, October, 1998. 相似文献
15.
《Tetrahedron letters》1987,28(23):2623-2626
2′-5′,3′-5′ Linked triadenylates have been synthesized by direct bisadenylylation of adenosine 2′ and 3′ hydroxyls with an adenosine 5′-phosphorochloridite followed by oxidation. 相似文献
16.
L. A. Gribov O. B. Zubkova A. A. Sigarev V. A. Bykov 《Journal of Structural Chemistry》1993,34(1):164-170
A complete calculation has been performed for the infrared spectrum of the molecule of 3,3-dichloroindanthrone, including vibration frequencies and intensities and the spectral curve. The satisfactory agreement that has been obtained between the calculated and experimental spectra has made it possible to interpret the spectrum in detail; to determine the characteristic spectral regions for manifestation of vibrations that pertain in form to such structural fragments of the molecule as the anthraquinone fragment, the nitrogen-containing ring, and the ring that embodies a hydrogen bond; and to obtain information on the sensitivity of vibrations to chlorination of indanthrone. The features that have been revealed have the character of a spectrum/structure correlation and can be used for analytical purposes.K. A. Timiryazev Agricultural Academy. Scientific-Research Institute of Physical Problems. Translated from Zhurnal Strukturnoi Khimii, Vol. 34, No. 1, pp. 190–196, January–February, 1993. 相似文献
17.
Kinetic models for the ‘molecular’ mechanochemical syntheses of α- and β-dialkyl 2,2′-bipyridyl-4,4′-dicarboxylate complexes of palladium (PdLnI2, where n specifies the number of carbons in the alkyl chain of the ligand and α and β refer to the substitution of the alkyl chain) are explored. The Johnson–Mehl–Avrami–Yerofeev–Kolmogrov (JMAYK) model was determined to best fit the data obtained via 1H NMR spectroscopic analysis of the reaction mixtures over time. A rate enhancement, and corresponding increase in the Avrami exponent, was observed when the complex formed was liquid crystalline at milling temperatures. 相似文献
18.
A. N. Perevoshchikova A. A. Gorbunov Yu. S. Rozhkova P. A. Slepukhin Yu. V. Shklyaev 《Russian Journal of Organic Chemistry》2014,50(4):513-517
The reaction of 1-(4-methoxyphenyl)-1-(1-methylcyclohexyl)ethanol with nitriles in concentrated sulfuric acid afforded 1′-substituted 6′-methoxy-4′,4′-dimethyl-4′H-spiro[cyclohexane-1,3′-isoquinolines] as a result of consecutive Wagner-Meerwein rearrangement and Ritter reaction. 相似文献
19.
Max Hasenbeck Tizian Müller Arthur Averdunk Dr. Jonathan Becker Dr. Urs Gellrich 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(9):e202104254
We herein report that the reaction of Piers′ borane, i. e. HB(C6F5)2, with an excess of arylacetylenes at room temperature leads to tetramerization of the acetylene and the diastereoselective formation of boryl-substituted tetra-aryl-tetrahydropentalenes. The reaction mechanism was investigated by isotope labeling experiments and DFT computations. These investigations indicate that a series of 1,2-carboboration reactions form an octatetraene that undergoes an electrocyclization. Two skeletal rearrangements then presumably lead to the formation of the tetrahydropentalene core. Overall, this intricate and unprecedented transformation comprises five carbon-carbon bond formations in a single reaction. 相似文献
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《Tetrahedron letters》1986,27(13):1521-1522
Cleavage of 2−O-tetrahydropyranyl groups from ribonucleoside derivatives used in solid-phase oligoribonucleotide synthesis takes place to an unacceptable extent during treatment with protic acid to remove 5′-O-pixyl groups. 相似文献