CH—Acids

Ch-Acids deals with the acidity of all organic compounds containing C-H bonds. CH-acidity characterizes thermodynamic stability of carbanions in a medium containing a proton donor as carbanion acceptor. The book primarily explains proton transfer stereochemistry or structure in relation to CH-acidity patterns. Methods to study equilibrium acidity; tabulation of pKa values of CH-acids; and equilibrium acidity as a function of CH-acid structures are presented. Topics on kinetic CH-acidity; stereochemistry of proton transfer in CH-acids; and factors obscuring experimental observation of the action of the Bronsted equation are discussed extensively. The text will be of importance to organometallic and organic chemists.

Preface

Chapter I. Equilibrium Acidity of CH-Acids

I. Introduction

II. CH-Acidities in Water. A comparison with OH-Acids

III. Methods of Measuring Ionization Equilibria of CH-Acids

1. Transmetalation Equilibria

2. The Cram MSAD Scale

3. Acidity in Dimethylsulphoxide

4. Acidity in Dimethoxyethane

5. Polarographic Scale of Acidity

6. The Electrochemical Method of Breslow

7. Acidity Scale for Acidic Hydrocarbons

8. Other Methods

9. Acidity of Arenonium Ions

Chapter II. Structure Effects on Equilibrium CH-Acidity

I. Acidity in the Gas Phase

II. Acidity in Solution

1. Hydrocarbons. s-Character. Conjugation

2. Compounds Containing Fluorine or Other Halogens. α Effect

3. Compounds with Strongly Acidic Substituents Containing a Heteroatom. Conjugation

4. Five-Membered Aromatic Heterocyclics. Inductive and Resonance Effects. d-Orbital Effect

5. Onium Compounds. Inductive Effect. d-Orbital Effect

6. Sulphones. Gauche-Effect

Chapter III. Kinetic CH-Acidity

I. Hydrogen Isotope Exchange. Protophilic Mechanism

II. Hydrogen Isotope Exchange Rates in CH-Acids of Various Types

1. Hydrocarbons

2. Halogenated Derivatives

3. Nitro Compounds

4. Carbonyl Compounds

5. Heterocyclic Compounds

6. Carboranes

7. Complexes of Transition Metals

III. Kinetic Isotope Effect and Exchange Mechanism

Chapter IV. Stereochemistry of Proton Transfer

I. Cyclopropane CH-Acids

II. Vinyl CH-Acids

III. CH-Acids with Substituents Containing Sulfur

1. Sulphones

2. Sulphoxides

3. Sulphides

4. Sulphonium Salts

5. Other Systems

IV. CH-Acids Forming Ambidental Anions

V. Fluorene CH-Acids

VI. Benzyl CH-Acids

VII. Proton Transfer Accompanied by Re-arrangements in Unsaturated Systems

1· Intramolecular Proton Transfer

2. Structure Effect upon Isomerization of Allyl Systems

3. Effects of the Medium

Chapter V. Relationship between Equilibrium and Kinetic Acidity

I. Three-Step Proton Transfer Mechanism

II. Theoretical Interpretation of the Brönsted Equation

III. "Normal" Brönsted Plots

IV. Correlations of Proton Transfer Rate with Acidity Function H-

V. Brönsted Plots with Anomalous Slopes

VI. H2O/OH- System

VII. Conclusion

References

Index

Additional References for 1975 to 1978