Steric Effects on Reaction Rates – III. Application of Force‐Field Calculations to Chromic Acid Oxidation of Alcohols

Müller, Paul; Blanc, Jacky; Lenoir, Dieter

doi:10.1002/hlca.19820650410

Cited by 8 publications

(1 citation statement)

References 41 publications

(9 reference statements)

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“…In particular, the tri(tert-buty1)methyl cation (5+) which deviated badly, is Table I now quite well-behaved. This raises some disturbing questions concerning the reliability of the alcohol force field, which we have used in previous work [26], and which will have to be re-examined. …”

Section: 202~6]~~tyl (45-mentioning

confidence: 97%

Steric Effects on Reaction Rates. Part XII. Force‐Field Calculations for the Solvolysis of Cyclobutyl and Tricyclyl Derivatives

Müller

Milin

1991

Helvetica Chimica Acta

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(1 6.VIII.91) Force-field parameters have been developed for the molecular-mechanics calculation of tertiary carbenium ions with tricyclane structure, for tertiary cyclobutyl and cubyl cations. The cyclobutyl parameters are also applicable to tertiary 7-norbornyl cations. Satisfactory plots are obtained for correlation of the rates of solvolysis with the differences in steric energies between carbenium ions and the corresponding bromides.Introduction. -Bridgehead derivatives constitute a mechanistically homogeneous series in solvolysis reactions. Their solvolytic reactivity has been investigated systematically by Schleyer and coworkers [I-31. The reactions were found to be dominated by strain changes upon change of hybridization of the reacting C-atom from sp3 to sp2 in going to the transition state. These strain changes were calculated by molecular mechanics [3], and they were successfully correlated with the experimental rate constants (log k ) for solvolysis of bridgehead chlorides, bromides, p -toluenesulfonates, and trifluoromethane sulfonates. The solvolytic reactivity of bridgehead derivatives varies enormously with the structure of the substrate, and it is impossible to measure the rate constants with one and the same leaving group and under identical experimental conditions. For quantitative strain-reactivity correlations, a uniform reactivity scale is a prerequisite. Such a reactivity scale has been set up. Bentley and Roberts [4] have critically established rate constants for several bridgehead derivatives with different leaving groups. It was found that relative rate constants in the series are almost independent from the leaving group and the solvent, and subsequently to this observation, correction factors for solvent and leaving group changes (chlorides, bromides, p-toluenesulfonates, and trifluoromethane sulfonates) have been proposed. A reactivity scale for standard conditions (TsO leaving group solvolyzing at 70°in 80 % aq. EtOH) spanning a rate range of 22 log units was established. Similarly, conversion factors for p -nitrobenzoate solvolysis and for acid-catalyzed dehydration of tertiary alcohols in the bridgehead and nonbridgehead series have been determined by using linear free-energy relationships [5]. The extrapolated rate constants, when taken from different conditions, agree in general within 0.5 log units.The original strain-reactivity calculations for bridgehead derivatives were carried out with a preliminary force field which was later abandoned. More recently the strain calculations of Schleyer have been repeated with a carbenium ion force field similar

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Section: 202~6]~~tyl (45-mentioning

confidence: 97%

Steric Effects on Reaction Rates. Part XII. Force‐Field Calculations for the Solvolysis of Cyclobutyl and Tricyclyl Derivatives

Müller

Milin

1991

Helvetica Chimica Acta

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Synthesis of the Right-Hand Substructure of Solanoeclepin A

Brière¹,

Blaauw²,

Benningshof³

et al. 2001

Eur. J. Org. Chem.

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Thermochemistry of Olefins, Carbonyl Compounds and Imines

Slayden

Liebman

2009

Patai's Chemistry of Functional Groups

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Introduction: Scope and Definitions Acyclic Olefins Cyclic Olefins with a  CH  CH  Group Exo ‐ vs Endo ‐Cyclic Double Bonds B redt's Rule, Bridgehead Olefins and Cyclic Species with a A > C  CH  Olefinic Linkage Cyclic Olefins Containing a Tetrasubstituted Double Bond Olefins with Aromatic Substituents Acyclic Aldehydes and Ketones Alicyclic Ketones Carbonyl Compounds with Aryl Substituents Polycarbonyl Compounds Imines

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Steric Effects on Reaction Rates – III. Application of Force‐Field Calculations to Chromic Acid Oxidation of Alcohols

Cited by 8 publications

References 41 publications

Steric Effects on Reaction Rates. Part XII. Force‐Field Calculations for the Solvolysis of Cyclobutyl and Tricyclyl Derivatives

Steric Effects on Reaction Rates. Part XII. Force‐Field Calculations for the Solvolysis of Cyclobutyl and Tricyclyl Derivatives

Synthesis of the Right-Hand Substructure of Solanoeclepin A

Thermochemistry of Olefins, Carbonyl Compounds and Imines

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