Kinetics of ring opening of propylene sulphide: 1. Alkali metal and cryptated alkali metal carbazyl salts

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.

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ChemInform Abstract: KINETICS OF THE CHELATE EFFECT. RING CLOSING AND RING OPENING IN CIS-DICHLORO(DIMETHYL SULFOXIDE)(3-AMINOPROPYL)AMMONIUM)- AND -((4-AMINOBUTYL)AMMONIUM)PLATINUM(II) CHLORIDE. EFFECT OF RING SIZE

Chemischer Informationsdienst ◽

10.1002/chin.197849328 ◽

1978 ◽

Vol 9 (49) ◽

Author(s):

R. ROMEO ◽

S. LANZA ◽

D. MINNITI ◽

M. L. TOBE

Keyword(s):

Dimethyl Sulfoxide ◽

Ring Opening ◽

Ring Size ◽

Chelate Effect ◽

Chloride Effect ◽

In Cis ◽

Kinetics Of ◽

Effect Ring

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Infrared spectroscopy as an effective tool in ring-opening metathesis polymerization: monitoring the polymerization kinetics of norbornene with amine-based Ru catalysts in real time

Reaction Kinetics Mechanisms and Catalysis ◽

10.1007/s11144-017-1147-5 ◽

2017 ◽

Vol 120 (2) ◽

pp. 663-672 ◽

Cited By ~ 5

Author(s):

Vinicius K. Tomazett ◽

Willy G. Santos ◽

Benedito S. Lima-Neto

Keyword(s):

Infrared Spectroscopy ◽

Real Time ◽

Ring Opening ◽

Polymerization Kinetics ◽

Ring Opening Metathesis Polymerization ◽

Ru Catalysts ◽

Metathesis Polymerization ◽

Kinetics Of

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Derivatives of isatin in aqueous solution. I. Kinetics of ring opening of Isatin-5-sulfonate

Australian Journal of Chemistry ◽

10.1071/ch9810365 ◽

1981 ◽

Vol 34 (2) ◽

pp. 365 ◽

Cited By ~ 7

Author(s):

H Stunzi

Keyword(s):

Ring Opening ◽

Rate Of Change ◽

Spectroscopic Methods ◽

Ph Values ◽

Buffer Region ◽

Pka Value ◽

Back Titration ◽

Kinetics Of ◽

Derivatives Of ◽

Sulfonate Anion

The reactions of isatin-5-sulfonate anion (si-) which cause a hysteresis in pH titrations were studied by pH-metric and n.m.r, spectroscopic methods. Rapid alkalimetric titrations [I 0.15 M (KNO3),37�] gave the pKa value corresponding to the addition of OH- to si- [pKa(ring) 9.55]. The slow ring opening to the sulfonatoisatate dianion (sia2-) led to a drift of the pH values towards an equilibrium buffer region. Its pKa, value [pKa(eq) 3.44] corresponds to the reaction si-+H2O ↔ sia 2-+H+ Rapid back-titration gave the pKa value of the ring-opened species Hsia- [pKa(open) c. 1.3]. The rate law for the ring opening d[sia]/dt=k2 [siOH](OH)+k1*[si] was obtained from the rate of change of pH. N-Methylisatin-5-sulfonate behaves analogously.

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