Molecular Catalysts

Contents

List of Contributors

Foreword

Introduction

Part I Mechanisms of Elementary Reactions in Catalytic Processes

Chapter 1 Quantum Dynamics of Molecular Elementary Processes in Catalytic Transformations

1.1 Introduction

1.2 Structural and Energetic Aspects

1.3 Quantum Dynamical Calculations

1.3.1 Reaction Path Energy Profiles

1.3.2 Wave Packet Propagation for Late-Transition-Metal Complexes

1.3.3 Norm Decay and Lifetimes

1.3.4 Quantum Dynamics of Ethylene Insertion in Chromium Complexes

1.4 Summary and Outlook

Acknowledgments

References

Chapter 2 Activation of Small Molecules with Metal and Metal Oxide Clusters in Inert Gas Matrixes

2.1 Introduction

2.2 The Matrix Isolation Technique - Advantages and Limitations

2.2.1 Thermal Evaporation Versus Laser Ablation

2.2.2 Metal or CsI Substrates for the Matrix

2.3 Formation and Characterization of Metal Atom Dimers and Clusters

2.4 Reactions of Atom Dimers or Clusters

2.5 Formation and Characterization of Metal Oxides

2.6 Reactions Involving Metal Oxides

2.7 Concluding Remarks

Acknowledgments

References

Chapter 3 Toward Single-Molecule Catalysis

3.1 Introduction

3.1.1 Single-Molecule Enzymology

3.1.2 Single-Molecule Studies in Chemistry

3.1.2.1 Single-Molecule Studies in Heterogeneous Catalysis

3.1.2.2 Single-Molecule Chemistry in Homogeneous Catalysis

3.2 Probes for Single-Molecule Chemistry

3.2.1 Fluorescence Properties: Overall Considerations

3.2.2 Fluorogenic Substrates

3.2.3 Substrates for Reversible Reactions

3.2.4 Substrates for Irreversible Reactions

3.3 Approaching Single-Molecule Studies in Homogeneous Catalysis

3.3.1 Fluorophore-Labeled Cu(II) Chelators and Substrates

3.3.2 BODIPY Substrates for Probing Reactions of Double Bonds

3.4 Discussion and Perspectives

Acknowledgments

References

Chapter 4 Intermediates and Elementary Reactions in Gold Catalysis

4.1 Introduction

4.2 The Initial Step: π-Coordination of the Substrate

4.3 The Nucleophilic Addition: Vinylgold and Alkylgold Intermediates

4.4 The Reaction of the Organogold Intermediates with Electrophiles

4.5 "Vinylidene" Gold(I) Intermediates

4.5.1 Setting the Stage

4.5.2 An Unexpected Regioselectivity Raises Questions

4.5.3 The Mechanistic Hypothesis

4.5.4 The Other Pathway

4.5.5 Gold Allenylidenes as Analogs of Gold Vinylidenes?

4.5.6 Dual Activation Catalysts

4.6 Protons and Hydride in Gold Catalysis

4.7 Future Perspectives

References

Chapter 5 Diastereoselectivity in Alkene Metathesis

5.1 Introduction

5.2 Stereoselective Alkene Metathesis Catalysts

5.3 Combining Catalytic Activity and Stereoselectivity in Ruthenium Carbenes: an Antagonism?

5.4 Stereoselectivity in Ring-Opening Metathesis Polymerization (ROMP)

5.5 Outlook

5.6 Summary

References

Part II New Catalysts - New and Old Reactions

Chapter 6 Oxidation Catalysis with High-Valent Nonheme Iron Complexes

6.1 Introduction

6.2 Bispidine Ligands

6.3 Oxidation of the Ferrous Precursors

6.4 Spin States of the Ferryl Catalysts

6.5 Redox Properties of the Ferryl Oxidants

6.6 Reactivity of the Ferryl Compounds

6.6.1 Olefine Oxidation

6.6.2 Alkane Oxidation

6.6.3 Sulfoxidation

6.6.4 Water Oxidation

6.6.5 Dioxygen as Oxidant

6.7 Conclusion

Acknowledgment

References

Chapter 7 Single-Site Organochromium Catalysts for High Molecular Weight Polyolefins

7.1 Introduction

7.2 Ligand Design

7.3 Chromium Complexes of Non-Cp Ligands

7.3.1 Neutral Tridentate Ligands

7.3.2 Anionic Ligands

7.4 Chromium Complexes Based on Cp

7.4.1 Cp Systems with Covalently Bound Additional Donor Functions

7.5 Polymerization Behavior of Donor-Functionalized Cp Chromium Complexes Developed in Heidelberg

7.5.1 Structural Features

7.5.2 Catalyst Activation and Catalytic Activities

7.5.3 Chain Termination and Molecular Weights

7.6 En Route to Tunable Catalysts

7.7 Conclusion

References

Chapter 8 Ligand Design and Mechanistic Studies for Ni-Catalyzed Hydrocyanation and 2-Methyl-3-Butenenitrile Isomerization Based upon Rh-Hydroformylation Research

8.1 Introduction

8.2 Recent Advances in Ni-Catalyzed Hydrocyanation and Isomerization Reactions

8.2.1 Hydrocyanation of Vinylarenes

8.2.2 Hydrocyanation of 1,3-Dienes

8.2.3 Hydrocyanation of trans-3-Pentenenitrile

8.2.4 Isomerization of 2-Methyl-3-Butenenitrile

8.3 Recent Advances in Ni-Catalyzed Hydrocyanation and Isomerization Reactions Employing the TTP-Ligand Family

8.3.1 Genesis of the TTP-Ligand Family

8.3.2 Ni-Catalyzed Isomerization and Hydrocyanation with TTP-Type Phosphonite Ligands

8.3.3 Ni-Catalyzed Hydrocyanation Involving TTP-Type Phosphine Ligands

8.3.4 Applications and Mechanistic Studies of TTP-Type Phosphine Ligands in Ni-Catalyzed 2M3BN Isomerization

Acknowledgments

References

Chapter 9 Strongly Electron Donating Tridentate N-Heterocyclic Biscarbene Ligands for Rhodium and Iridium Catalysts

9.1 Introduction

9.2 Ligand Systems

9.3 Synthesis and Reactivity of the Complexes

9.3.1 Synthesis of M(I) Complexes

9.3.2 Synthesis of M(III) Complexes

9.4 Catalytic Activities of the Rh Complexes

9.5 Catalytic Activities of the Ir Complexes

9.6 Discussion

9.7 Summary, Conclusion, and Outlook

References

Chapter 10 NHCP Ligands for Catalysis

10.1 Introduction

10.2 Recent Advances in Catalysis with NHCP Ligands

10.2.1 Cross-Coupling Catalysis and Related Reactions

10.2.2 Miscellaneous Reactions

10.3 Recent Advances in Asymmetric Catalysis with Chiral NHCP Ligands

10.4 Recent Advances in NHCP Chemistry Featuring Bulky, Electron-Rich, Small-Bite-Angle Ligands

10.4.1 Ligand Synthesis of N-Phosphino- and N-Phosphinomethyl NHCs

10.4.2 N-Phosphino-NHC Transition-Metal Complexes

10.4.3 N-Phosphinomethyl-NHC Ruthenium Alkylidene Complexes

References

Part III Catalysts in Synthesis

Chapter 11 Ir-Catalyzed Asymmetric Allylic Substitution Reactions - Fundamentals and Applications in Natural Products Synthesis

11.1 Introduction

11.2 Background on Reaction Mechanism

11.3 Dibenzocyclooctatetraene (dbcot) as Ancillary Ligand

11.4 Applications in Organic Synthesis

11.4.1 Allylic Substitution in Combination with Ring Closing Metathesis

11.4.2 Domino-Hydroformylation-Cyclization (Hydroaminomethylation)

11.4.3 The Allylic Substitution in Combination with the Suzuki-Miyaura Reaction

11.4.4 Reactions of Enines Derived from Allylic Substitution Products

11.5 Conclusions

Acknowledgments

References

Chapter 12 Sequential Catalysis Involving Metal-Catalyzed Cycloisomerizations and Cyclizations

12.1 Introduction

12.2 Sequences Initiated by Cycloisomerizations

12.2.1 Sequentially Pd-Catalyzed Sequences Initiated by Cycloisomerizations

12.2.2 Sequentially Rh-Catalyzed Sequences Initiated by Cycloisomerizations

12.3 Sequences Initiated by Ring-Closing Olefin Metathesis

12.3.1 Ring-Closing Metathesis-Isomerization Sequences

12.3.2 Ring-Closing Metathesis-Oxidation Sequences

12.4 Sequences Initiated by Alkynylation and Carbopalladative Insertions

12.5 Sequences Intercepted by Cyclizations

12.6 Conclusion

Acknowledgment

Abbreviations

References

Chapter 13 C-N-Coupling Reactions in Catalytic One-Pot Syntheses Using Molecular Group 4 Catalysts

13.1 Introduction

13.2 Group 4 Metal Catalysts for the Hydroamination and Hydrohydrazination of C-C Multiple Bonds as well as Complex Reaction Sequences Based Thereon

13.3 Case Histories

13.3.1 Highly Active Titanium Catalysts for the Hydrohydrazination of Terminal Alkynes and Aminoguanylation of Carbodiimides

13.3.2 A Zirconium-Catalyzed Non-Fischer-Type Pathway to Indoles

References

Chapter 14 Sequential Catalysis for the Stereoselective Synthesis of Complex Polyketides

14.1 Complex Polyketides

14.2 Domino Nucleophilic Addition-Tsuji-Trost Reaction

14.2.1 Concise Synthesis of Tetrahydropyrans by a Tandem oxa-Michael-Tsuji-Trost Reaction

14.2.2 Concise Synthesis of Acetal-Protected 1,3-syn-Diols by a Tandem Hemiacetal/Tsuji-Trost Reaction

14.2.3 General Concept and Further Applications for Diamine and Aminoalcohol Synthesis

14.3 Sequential Diyne Cyclization and Regioselective Opening of Zirconacyclopentadienes

14.4 Conclusion and Perspectives

References

Chapter 15 Modular Assembly of Chiral Catalysts with Polydentate Stereodirecting Ligands

15.1 Introduction

15.2 A Modular Synthesis of C3- and C1-Chiral 1,1,1-Tris(oxazolyl)ethanes ("Trisox")

15.2.1 C3-Chirality in Polymerization Catalysis with Rare-Earth Complexes

15.2.2 Trisox as a Bidentate Ligand: Chiral Trisoxazolines in Copper(II) Lewis Acid Catalysis and Palladium-Catalyzed Asymmetric Allylic Substitutions

15.3 The Boxmi Pincer System: a Highly Efficient Modular Stereodirecting Ligand for a Broad Range of Catalytic Reactions

15.4 Bidentate N-Heterocyclic Carbene Ligands Incorporating Oxazoline Units

15.5 New Modular Di- and Tridentate Phospholane Ligands

15.5.1 Cyclohydroaminations of γ-Allenyl Sulfonamides with Mono-, Bis-, and Trisphospholane Gold(I) Catalysts

References

Part IV Structures and Mechanisms in Biological Systems

Chapter 16 Beating and Employing X-Ray-Induced Radiation Damage in Structural Studies of Hemoproteins

16.1 Introduction

16.2 Cytochrome P450 Enzymes

16.2.1 The Reaction Cycle of P450cam at High Structural Resolution

16.2.2 Chloroperoxidase Compound

16.3 Photoelectrons - Friend and Foe

16.4 X-ray Free-Electron Lasers

References

Chapter 17 The Catalytic Strategy of P-O Bond-Cleaving Enzymes: Comparing EcoRV and Myosin

17.1 Introduction

17.1.1 How Do Enzymes Achieve Catalysis?

17.1.2 Computational Investigation of Enzymatic Mechanisms

17.1.3 Enzymes that Catalyze Reactions Involving Phosphate

17.1.4 Endonuclease Enzymes

17.1.5 NTPase Enzymes

17.1.6 Hydrolysis Mechanism

17.2 Results

17.3 Conclusions

17.4 Methods

References

Chapter 18 Selective Hybrid Catalysts Based on Nucleic Acids

18.1 Introduction

18.2 Hybrid Catalysis

18.3 DNA-Based Hybrid Catalysis

18.4 Organometallic Chemistry with Nucleic Acids

18.5 Combinatorial Selections of Catalysts from Nucleic Acid Libraries

18.6 Site-Specific Internal Functionalization of Nucleic Acids with Transition-Metal Ligands and Other Moieties

18.7 Metallation of DNA-Ligand Conjugates

18.8 Site-Specific Terminal Functionalization of Nucleic Acids with Substrates

18.9 Allylic Aminations by DNA-Based Hybrid Catalysts

18.10 Summary and Outlook

References

Part V Studies of Immobilized Catalysts - Introduction

V.1 Introduction

V.2 Covalent Immobilization of Catalysts

V.3 Support Materials

V.4 Examples of Immobilized Catalyst Systems

Chapter 19 Dendrimers as Platforms for Stereoselective Catalysis

19.1 Introduction

19.2 Fixation of Chiral Catalysts on Dendrimers and Hyperbranched Polymers

19.3 Case Histories

19.3.1 "Dendritic Effects" Observed for Immobilized Pyrphos-Based Hydrogenation Catalysts

19.3.2 BINAP-Copper(I) Hydrosilylation with Functionalized PPI and PAMAM Dendrimers as well as Hyperbranched Polymers

19.3.3 "Catalysis in a Tea Bag" with Dendrimer-Immobilized Bis- and Trisoxazoline Copper Catalysts

19.4 Conclusion and Outlook

References

Chapter 20 Solid Phases as Protective Environments for Biomimetic Catalysts

20.1 Introduction

20.2 Site Isolation Experienced by Matrix-Bound Transition-Metal Complexes

20.3 Immobilized Structural and Spectroscopic Active Site Models

20.4 Elementary Reaction Steps Performed by Solid-Phase Supported Complexes

20.5 Immobilized Functional Active Site Models

20.6 Final Remarks

Abbreviations

References

Chapter 21 High-Throughput Screening of Catalysts and Reactions

21.1 Introduction

21.2 Technical Requirements for On-Column Reaction Chromatography

21.2.1 Experimental Setups of On-Column Reaction Chromatography

21.2.2 Preparation of Capillary Reactors

21.2.3 High-Throughput Approach

21.3 Determination of Kinetic Data

21.3.1 Classical Reaction Kinetics for On-Column Reaction Chromatographic Experiments with Reaction and Consecutive Separation

21.3.2 Evaluation of Conversion Profiles Obtained by On-Column Reaction Chromatography

21.4 Determination of Activation Parameters

21.5 On-Column Reaction Chromatography for the Investigation of Catalytic Reactions

21.5.1 Hydrogenations over Noble Metal Nanoparticles

21.5.2 Ring-Closing Metathesis

21.5.3 Gosteli-Claisen Rearrangement

21.5.4 Combinatorial High-Throughput Screening: Catalyst by the Meter

21.6 Outlook

References

Index

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