Kooperativer Bibliotheksverbund

UID:

Umfang: 302 p. 5 illus. , online resource.

Ausgabe: 1st ed. 1977.

ISBN: 9781461341185

Anmerkung: 1. That Fascinating Nonclassical Ion Problem -- 1.1. Introduction -- 1.2. Origins -- 1.3. The Nonclassical Ion Era -- 1.4. Steric Assistance -- 1.5. An Alternative Interpretation -- 1.6. The Rococo Period of Carbonium Ion Structures -- 1.7. Difficulties in Challenging an Accepted Theory -- 1.8. Further Difficulties-A "Soft" Theory -- 1.9. Still Further Difficulties-Selective Reviews -- 1.10. Conclusion -- Comments -- 2. Steric Assistance in Solvolytic Processes -- 2.1. Introduction -- 2.2. Steric Assistance in the Solvolysis of Highly Branched Alkyl Derivatives -- 2.3. Steric Assistance in the Relative Effects of Methyl and tert-Butyl Groups -- 2.4. Steric Effects in Norbornyl Derivatives -- 2.5. Steric Effects in Ring Systems -- 2.6. Conclusion -- Comments -- 3. ?-Participation-A Factor in Fast Rates? -- 3.1. Introduction -- 3.2. n-, ?- and ?-Participation -- 3.3. ?-Participation and Fast Rates -- 3.4. ?-Participation vs. Steric Assistance -- 3.5. Steric Assistance-Not ?-Participation -- 3.6. The Fast Rates of Exo-Norbornyl and Cyclopropylcarbinyl -- Comments -- 4. Carbon-Bridged Cations -- 4.1. Introduction -- 4.2. What Is a Nonclassical Ion? -- 4.3. ?-Bridging vs. Hyperconjugation -- 4.4. Static Classical, Equilibrating Classical, or ?-Bridged Cations -- 4.5. Stereochemistry and ?-Bridged Cations -- 4.6. ?-and Aryl-Bridged Cations -- 4.7. Conclusion -- Comments -- 5. The Cyclopropylcarbinyl Cation -- 5.1. Introduction -- 5.2. Exceptionally Fast Rates of Solvolysis -- 5.3. Rearrangements in the Solvolysis of Cyclopropylcarbinyl Derivatives -- 5.4. ?-Bridged Structures for the Cation -- 5.5. Stereochemical Characteristics -- 5.5. Conclusion -- Comments -- 6.The 2-Norbornyl Cation -- 6.1. Introduction -- 6.2. Nonclassical "Structures" for the 2-Norbornyl Cation -- 6.3. Basic Facts -- 6.4. Transition State or Intermediate -- 6.5. Equilibrating Cations -- 6.6. Are Exo Rates Unusually Fast? -- 6.7. Do the High Exo:Endo Rate Ratios Require ?-Bridged Cations? -- 6.8. Do the High Exo:Endo Product Ratios Require ?-Bridged Cations? -- 6.9. Theoretical and Empirical Solutions -- 6.10. Conclusion -- Comments -- 7. Stabilized 2-Norbornyl Cations -- 7.1. Introduction -- 7.2. The Gassman-Fentiman Approach -- 7.3. Exo:Endo Rate Ratios in 2-p-Anisyl-2-norbornyl -- 7.4. Exo:Endo Rate Ratios in 2-p-Anisyl-2-camphenilyl -- 7.5. Exo:Endo Product Ratios -- 7.6. Goering-Schewene Diagrams -- 7.7. Other 2-p-Anisyl Systems -- 7.8. Other Stabilized Systems -- 7.9. The Selectivity Principle and the 2-Norbornyl Problem -- 7.10. Conclusion -- Comments -- 8. Exo:Endo Rate Ratios as a Steric Phenomenon -- 8.1. Introduction -- 8.2. Steric Characteristics of the Norbornyl System -- 8.3. Steric Characteristics of the 7,7-Dimethylnorbornyl System -- 8.4. Steric Hindrance to Ionization -- 8.5. Misconceptions -- 8.6. Steric Hindrance to Ionization and the Foote-Schleyer Correlation -- 8.7. Steric Effects in U-Shaped Systems -- 8.8. Exo:Endo Rate and Product Ratios as a Steric Phenomenon -- 8.9. Conclusion -- Comments -- 9. Equilibrating Tertiary 2-Norbornyl Cations -- 9.1. Introduction -- 9.2. Theoretical Considerations -- 9.3. The 1,2-Di-p-anisyl-2-norbornyl Cation -- 9.4. The 1,2-Diphenyl-2-norbornyl Cation -- 9.5. The 1,2-Dimethyl-2-norbornyl System -- 9.6. Conclusion -- Comments -- 10. Effect of Increasing Electron Demand -- 10.1. Introduction -- 10.2. Basic Considerations -- 10.3. Electron Demand in ?-Systems -- 10.4. Electron Demand in Cyclopropylcarbinyl Systems -- 10.5. Electron Demand in 2-Norbornyl Systems -- 10.6. Increasing Electron Demand in Secondary 2-Norbornyl -- 10.7. Extrapolation of Data from the Tertiary to the Secondary Systems -- 10.8. Conclusion -- Comments -- 11. Substituent and Structural Effects in 2-Norbornyl -- 11.1. Introduction -- 11.2. Secondary vs. Tertiary 2-Norbornyl Cations -- 11.3. Substituents as a Probe for Charge Delocalization -- 11.4. The Search for Charge Delocalization at C6 -- 11.5. The Search for Charge Delocalization at C2 -- 11.6. The Search for Charge Delocalization at C1 -- 11.7. Deuterium as a Substituent -- 11.8. Deactivating Substituents -- 11.9. Structural Modifications -- 11.10. Conclusion -- Comments -- 12. Capture of Unsymmetrical 2-Norbornyl Cations -- 12.1. Introduction -- 12.2. Deamination of 2-Norbornylamine -- 12.3. Attempted Trapping of Unsymmetrical Cations in Solvolytic Processes -- 12.4. Capture of Unsymmetrical Cations in Solvolytic Processes -- 12.5. Additions to 2,3-Dideuterionorbornene -- 12.6. Addition of Deuterium Chloride to Norbornene -- 12.7. Addition of Deuteriotrifluoroacetic Acid to Norbornene -- 12.8. Addition of Perdeuterioacetic Acid to Norbornene -- 12.9. Resumé -- 12.10. Conclusions -- Comments -- 13. Equilibrating Cations under Stable Ion Conditions -- 13.1. Introduction -- 13.2. Equilibrating Cations -- 13.3. Applicability of Results to Solvolysis -- 13.4. 13C NMR Shifts as a Measure of Charge Delocalizations -- 13.5. Nonadditivity of 13C Shifts as a Basis for Nonclassical Structures -- 13.6. PMR Spectra -- 13.7. ESCA Spectra -- 13.8. Cation Stabilities -- 13.9. Conclusion -- Comments -- 14. New Concepts-New Systems -- 14.1. Introduction -- 14.2. The Hyperconjugative Model -- 14.3. The Exo-6-H Participation Model -- 14.4. The Search for a Stereoelectronic Contribution -- 14.5. New Proposed ?-Bridged Systems -- 14.6. Conclusion -- Comments -- 15. Final Comments -- 15.1. Introduction -- 15.2. The Search for ?-Participation and ?-Bridging -- 15.3. Does ?-Delocalization Exist? -- 15.4. Are There ?-Bridged Cations? -- 15.5. Position on ?-Bridged Cations -- 15.6. Conclusion -- Comments -- Epilog.

In: Springer Nature eBook

Weitere Ausg.: Printed edition: ISBN 9781461341208

Weitere Ausg.: Printed edition: ISBN 9780306309502

Weitere Ausg.: Printed edition: ISBN 9781461341192

Sprache: Englisch

DOI: 10.1007/978-1-4613-4118-5

URL: https://doi.org/10.1007/978-1-4613-4118-5