Kinetics of nucleophilic attack on co-ordinated organic moeities. Part 3. Effect of solvent on addition of pentane-2,4-dione to complexes of cyclic dienyls

1976 ◽  
pp. 2187 ◽  
Author(s):  
C. A. Mansfield ◽  
L. A. P. Kane-Maguire
Keyword(s):  
Nucleophilic Attack ◽  
Effect Of Solvent ◽  
Kinetics Of

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.

Acid-Catalyzed Hydration of Prop-2-en-1-ol and 2-Methylprop-2-en-1-ol: Correlation of Reactivity

1989 ◽  
Vol 42 (8) ◽  
pp. 1345 ◽  
Author(s):  
KP Herlihy
Keyword(s):  
Activation Parameters ◽  
Relative Reactivity ◽  
Nucleophilic Attack ◽  
Alternative Mechanism ◽  
Catalysed Reaction ◽  
Acid Catalyzed ◽  
Solvent Isotope ◽  
Kinetics Of

The kinetics of the acid-catalysed reaction of prop-2-en-1-ol and 2-methylprop-2-en-1-ol have been measured. The relative reactivity, solvent isotope ( kH+/kD +) and change in acidity effects, and activation parameters, have been determined and found to be similar to those of other alkenes. While this correlation of results for the hydration of both these alkenols can be interpreted in terms of the conventional Ad-E2 mechanism, computed values for the lifetime of possible carbocation intermediates suggest that an alternative mechanism for the reaction of prop-2-en-1-ol, in which nucleophilic attack by the solvent is concerted with protonation, is feasible.

Kinetics of nucleophilic attack on coordinated organic moieties

1979 ◽  
Vol 178 (2) ◽  
pp. C17-C19 ◽  
Author(s):  
L. Cosslett ◽  
L.A.P. Kane-Maguire
Keyword(s):  
Nucleophilic Attack ◽  
Kinetics Of

Kinetics of nucleophilic attack on coordinated organic moieties

1988 ◽  
Vol 347 (3) ◽  
pp. 383-390 ◽  
Author(s):  
Leon A.P. Kane-Maguire ◽  
Paul A. Mouncher ◽  
Albrecht Salzer
Keyword(s):  
Nucleophilic Attack ◽  
Kinetics Of
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