Mechanism of hydration and isomerisation of 4-ethylidene-2,6-di-tert-butyl-2,5-cyclohexadien-1-one. Kinetics, acid-base catalysis and solvent deuterium isotope effects

1979 ◽  
Vol 44 (1) ◽  
pp. 110-122 ◽  
Author(s):  
Jiří Velek ◽  
Bohumír Koutek ◽  
Milan Souček
Keyword(s):  
Aqueous Medium ◽  
Rate Equation ◽  
Kinetic Data ◽  
Isotope Effects ◽  
Base Catalysis ◽  
Quinone Methide ◽  
Reaction Products ◽  
Acid Base ◽  
Deuterium Isotope Effects ◽  
Hydroxybenzyl Alcohol

Competitive hydration and isomerisation of the quinone methide I at 25 °C in an aqueous medium in the region of pH 2.4-13.0 was studied spectrophotometrically. The only reaction products in the studied range of pH are 4-hydroxybenzyl alcohol (II) and 4-hydroxystyrene (III). The form of the overall rate equation corresponds to a general acid-base catalysis. The mechanism of both reactions for three markedly separated pH regions is discussed on the basis of kinetic data and solvent deuterium effect.

scholarly journals Solvent Deuterium Isotope Effects on Acid-Base Reactions. Part IV. Lyonium Ion-Catalyzed Hydrolysis of Tertiary Butyl Acetate in Isotopically Different Waters.

1969 ◽  
Vol 23 ◽  
pp. 713-714
Author(s):  
Pentti Salomaa ◽  
Martti Ketola ◽  
Charles Larsen ◽  
Per Halfdan Nielsen ◽  
Alf A. Lindberg ◽  
...  
Keyword(s):  
Butyl Acetate ◽  
Isotope Effects ◽  
Acid Base ◽  
Tertiary Butyl ◽  
Deuterium Isotope Effects ◽  
Hydrolysis Of

The oxidation of secondary alcohols by potassium tetraoxoferrate(VI)

1997 ◽  
Vol 75 (2) ◽  
pp. 129-139 ◽  
Author(s):  
Bruce E. Norcross ◽  
William C. Lewis ◽  
Huifa Gai ◽  
Nazih A. Noureldin ◽  
Donald G. Lee
Keyword(s):  
Acid Catalysis ◽  
Isotope Effects ◽  
Low Ph ◽  
Base Catalysis ◽  
Secondary Alcohols ◽  
Acid And Base ◽  
Deuterium Isotope Effects ◽  
Reactive Oxidant ◽  
Kinetics Of ◽  
Large Primary

The kinetics of the oxidation of 2-propanol, 1,1,1-trifluoro-2-propanol, 1,1,1,3,3,3-hexafluoro-2-propanol, 1-phenyl-2,2,2-trifluoroethanol, 1-(4-methylphenyl)-2,2,2-trifluoroethanol, 1-(3-bromophenyl)-2,2,2-trifluoroethanol, and 1-(3-nitrophenyl)-2,2,2-trifluoroethanol by potassium tetraoxoferrate(VI) have been studied under basic conditions. The products are ketones, formed in almost quantitative yields, iron(III) hydroxide, and dioxygen. The reactions are characterized by substantial enthalpies of activation (40–60 kJ/mol), very unfavorable entropies of activation, large primary deuterium isotope effects, and a positive Hammett ρ value. Both acid and base catalysis are observed. Acid catalysis is attributed to formation of a more reactive oxidant, HFeO4−, at low pH. Base catalysis is attributed partly to the conversion of the reductants to alkoxide ions at high pH, and partly to the reaction of hydroxide ion with tetraoxoferrate(VI) to give a five-coordinated species, HOFeO43−, that reacts rapidly with nucleophiles. A reaction mechanism involving formation of an intermediate ferrate ester is proposed. Keywords: oxidation, alcohols, potassium tetraoxoferrate(VI), ferrate esters, base catalysis, acid catalysis.

Kinetic β-deuterium isotope effects for solvolysis of 1-methyl cyclopentyl chloride in an ethanol+ water mixture

1983 ◽  
Vol 61 (1) ◽  
pp. 116-117
Author(s):  
Ross Elmore Robertson ◽  
Edward Wong ◽  
John Marshall William Scott ◽  
Michael Jesse Blandamer ◽  
Rehmat Khan ◽  
...  
Keyword(s):  
Isotope Effect ◽  
Kinetic Data ◽  
Isotope Effects ◽  
Water Mixture ◽  
Deuterium Isotope Effect ◽  
Deuterium Isotope Effects

Kinetic data are reported for the solvolysis of 1-methyl cyclopentyl chloride in a 50% by volume ethanol+ water mixture. These data are combined with kinetic data for solvolysis of three deuterated analogues; 1-methyl-d3 cyclopentyl chloride, 1-methyl-2,2,5,5-d4 cyclopentyl chloride, and 1-methyl-d3-2,2,5,5-d4 cyclopentyl chloride, being the d3d4, and d7, derivatives respectively. The kinetic data are used to calculate the kinetic deuterium isotope effect, kH/kD. For these systems, the d7-isotope effect is close to the product of the d3 and d4 effects.

Theoretical study of deuterium isotope effects on acid–base equilibria under ambient and hydrothermal conditions

RSC Advances ◽  
2015 ◽  
Vol 5 (12) ◽  
pp. 9097-9109 ◽  
Author(s):  
Nelaine Mora-Diez ◽  
Yulia Egorova ◽  
Hart Plommer ◽  
Peter R. Tremaine
Keyword(s):  
Excellent Agreement ◽  
Theoretical Study ◽  
Isotope Effects ◽  
Acid Base ◽  
Hydrothermal Conditions ◽  
Deuterium Isotope Effects ◽  
Calculated Difference

The calculated difference between pKa values in H2O and D2O is in excellent agreement with experiment.

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