Anomerization of furanose sugars: kinetics of ring-opening reactions by proton and carbon-13 saturation-transfer NMR spectroscopy

1982 ◽  
Vol 104 (15) ◽  
pp. 4037-4044 ◽  
Author(s):  
Anthony S. Serianni ◽  
John Pierce ◽  
Shaw Guang Huang ◽  
Robert Barker
Keyword(s):  
Nmr Spectroscopy ◽  
Ring Opening ◽  
Saturation Transfer ◽  
Ring Opening Reactions ◽  
Kinetics Of

Intermediates from ring-opening reactions. Reactions of 2-chloro-5-nitropyridine and 2-chloro-3-nitropyridine with deuteroxide ion in selected solvents

1984 ◽  
Vol 62 (6) ◽  
pp. 1120-1123 ◽  
Author(s):  
John D. Reinheimer ◽  
Nicolas Sourbatis ◽  
Robert L. Lavallee ◽  
Douglas Goodwin ◽  
George L. Gould
Keyword(s):  
Ring Opening ◽  
Pyridine Ring ◽  
Ring Closure ◽  
Polar Solvents ◽  
Open Chain ◽  
Decomposition Products ◽  
Aqueous Sodium ◽  
Ring Opening Reaction ◽  
Ring Opening Reactions ◽  
Kinetics Of

Open chain intermediates from the ring-opening reaction of aqueous sodium deuteroxide (2 mol) with 2-chloro-5-nitropyridine (1 mol) and 2-chloro-3-nitropyridine (1 mol) were isolated. These intermediates were purified, analyzed for elemental composition, and characterized by various spectrophotometric techniques. The intermediate formed from 2-chloro-5-nitropyridine and two equivalents of deuteroxide ion reacts with additional deuteroxide in D2O in various polar solvents to reclose the pyridine ring. The kinetics of the ring closure reaction are reported and are supplemented with observations of salt and solvent effects upon the rate of closure. In addition, a mechanism for the ring closure is presented. The intermediate formed from 2-chloro-3-nitropyridine did not undergo a similar ring closure when reacted with additional deuteroxide, but instead formed various decomposition products. A reason for the failure of this ring closure is suggested.

Influence of ring-opening reactions on the kinetics of cottonseed oil epoxidation

2018 ◽  
Vol 50 (10) ◽  
pp. 726-741 ◽  
Author(s):  
Xiaoshuang Cai ◽  
Jun Liu Zheng ◽  
Adriana Freites Aguilera ◽  
Lamiae Vernières-Hassimi ◽  
Pasi Tolvanen ◽  
...  
Keyword(s):  
Ring Opening ◽  
Cottonseed Oil ◽  
Ring Opening Reactions ◽  
Kinetics Of

scholarly journals Soybean Oil Epoxidation: Kinetics of the Epoxide Ring Opening Reactions

Authorea ◽  
2020 ◽  
Author(s):  
Elio Santacesaria ◽  
Rosa Turco ◽  
Vincenzo Russo ◽  
Riccardo TESSER ◽  
Martino Di Serio
Keyword(s):  
Soybean Oil ◽  
Ring Opening ◽  
Epoxide Ring ◽  
Epoxide Ring Opening ◽  
Ring Opening Reactions ◽  
Kinetics Of

Catalytic activity of rhodium(I) complexes containing (ω-trimethylsilylalkyl)diphenylphosphines

1980 ◽  
Vol 45 (8) ◽  
pp. 2219-2223 ◽  
Author(s):  
Marie Jakoubková ◽  
Martin Čapka
Keyword(s):  
Catalytic Activity ◽  
Nmr Spectroscopy ◽  
Ir Spectroscopy ◽  
Electron Density ◽  
Phosphorus Atom ◽  
Proton Acceptor ◽  
Trimethylsilyl Group ◽  
Kinetics Of

Kinetics of homogenous hydrogenation of 1-heptene catalysed by rhodium(I) complexes prepared in situ from μ,μ'-dichloro-bis(cyclooctenerhodium) and phosphines of the type RP(C6H5)2 (R = -CH3, -(CH2)nSi(CH3)3; n = 1-4) have been studied. The substitution of the ligands by the trimethylsilyl group was found to increase significantly the catalytic activity of the complexes. The results are discussed in relation to the electron density on the phosphorus atom determined by 31P NMR spectroscopy and to its proton acceptor ability determined by IR spectroscopy.

Kinetics of the Imidazolium Ring-Opening of mRNA 5'-cap Analogs in Aqueous Alkali

2006 ◽  
Vol 71 (4) ◽  
pp. 567-578 ◽  
Author(s):  
Alicja Stachelska ◽  
Zbigniew J. Wieczorek ◽  
Janusz Stępiński ◽  
Marzena Jankowska-Anyszka ◽  
Harri Lönnberg ◽  
...  
Keyword(s):  
Electrostatic Interaction ◽  
Ring Opening ◽  
Nucleophilic Attack ◽  
Amino Groups ◽  
Hydroxide Ion ◽  
Methyl Group ◽  
Structural Modifications ◽  
Alkyl Groups ◽  
Imidazolium Ring ◽  
Kinetics Of

Second-order rate constants for the hydroxide-ion-catalyzed imidazolium ring-opening of several mono- and dinucleosidic analogs of mRNA 5'-cap have been determined. Intramolecular stacking of the two nucleobases in the dinucleosidic analogs, m7GpppN (m7G = 7-methylguanosine, N = 5'-linked nucleoside), and electrostatic interaction between the N-alkylated imidazolium ring and phosphate moiety have been shown to shield the m7G moiety against the nucleophilic attack of hydroxide ion. In addition, the effect of methylation of the nucleobase amino groups and replacement of the 7-methyl group with other alkyl groups have been studied. The influence of all the structural modifications studied turned out to be modest, the cleavage rates of the most and least reactive analogs (with the exception of non-phosphorylated nucleosides) differing only by a factor of 5.

ChemInform Abstract: Ring-Opening Reactions of Difluoro(methylene)cyclopropanes with Halogens and Amines.

ChemInform ◽  
2009 ◽  
Vol 40 (12) ◽  
Author(s):  
Xiao-Chun Hang ◽  
Qing-Yun Chen ◽  
Ji-Chang Xiao
Keyword(s):  
Ring Opening ◽  
Ring Opening Reactions

Substituent Effects in Mechanochemical Allowed and Forbidden Cyclobutene Ring-Opening Reactions

2021 ◽  
Author(s):  
Cameron L. Brown ◽  
Brandon H. Bowser ◽  
Jan Meisner ◽  
Tatiana B. Kouznetsova ◽  
Stefan Seritan ◽  
...  
Keyword(s):  
Ring Opening ◽  
Substituent Effects ◽  
Ring Opening Reactions

ChemInform Abstract: Discovery of μ-Opioid Selective Ligands Derived from 1-Aminotetralin Scaffolds Made via Metal-Catalyzed Ring-Opening Reactions.

ChemInform ◽  
2009 ◽  
Vol 40 (29) ◽  
Author(s):  
Chris Dockendorff ◽  
Shujuan Jin ◽  
Madeline Olsen ◽  
Mark Lautens ◽  
Martin Coupal ◽  
...  
Keyword(s):  
Ring Opening ◽  
Ring Opening Reactions ◽  
Selective Ligands ◽  
Metal Catalyzed
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