Preface ................................................... XIII
List of Contributors ...................................... XVII
1 Catalysis Involving the H* Transfer Reactions of First-
Row Transition Metals ........................................ 1
John Hartung and Jack R. Norton
1.1 H' Transfer Between M-H Bonds and Organic Radicals ...... 2
1.2 H' Transfer Between Ligands and Organic Radicals ........ 4
1.3 H' Transfer Between M-H and C-C Bonds ................... 7
1.4 Chain Transfer Catalysis ............................... 11
1.5 Catalysis of Radical Cyclizations ...................... 15
1.6 Competing Methods for the Cyclization of Dienes ........ 19
1.7 Summary and Conclusions ................................ 20
References .................................................. 21
2 Catalytic Reduction of Dinitrogen to Ammonia by Molybdenum .. 25
Richard R. Schrock
2.1 Introduction ........................................... 25
2.2 Some Characteristics of Triamidoamine Complexes ........ 26
2.3 Possible [HIPTN3N]Mo Intermediates in a Catalytic
Reduction of Molecular Nitrogen ........................ 30
2.3.1 MoN2 and MoN2- .................................. 30
2.3.2 Mo-N=NH ......................................... 33
2.3.3 Conversion of Mo(N2) into Mo-N=NH ............... 33
2.3.4 [Mo=N-NH2]+ ..................................... 35
2.3.5 Mo=N and [Mo=NH]+ ............................... 36
2.3.6 Mo(NH3) and [Mo(NH3)]+ .......................... 37
2.4 Interconversion of Mo(NH3) and Mo(N2) .................. 38
2.5 Catalytic Reduction of Dinitrogen ...................... 39
2.6 MoH and Mo(H2) ......................................... 41
2.7 Ligand and Metal Variations ............................ 44
2.8 Comments ............................................... 47
Acknowledgements ............................................ 48
References .................................................. 48
3 Molybdenum and Tungsten Catalysts for Hydrogenation,
Hydrosilylation and Hydrolysis .............................. 51
R. Morris Bullock
3.1 Introduction ........................................... 51
3.2 Proton Transfer Reactions of Metal Hydrides ............ 52
3.3 Hydride Transfer Reactions of Metal Hydrides ........... 54
3.4 Stoichiometric Hydride Transfer Reactivity of Anionic
Metal Hydride Complexes ................................ 56
3.5 Catalytic Hydrogenation of Ketones with Anionic Metal
Hydrides ............................................... 58
3.6 Ionic Hydrogenation of Ketones Using Metal Hydrides
and Added Acid ......................................... 59
3.7 Ionic Hydrogenations from Dihydrides: Delivery of the
Proton and Hydride from One Metal ...................... 64
3.8 Catalytic Ionic Hydrogenations With Mo and W
Catalysts .............................................. 65
3.9 Mo Phosphine Catalysts With Improved Lifetimes ......... 69
3.10 Tungsten Hydrogenation Catalysts with N-Heterocyclic
Carbene Ligands ........................................ 70
3.11 Catalysts for Hydrosilylation of Ketones ............... 71
3.12 Cp2Mo Catalysts for Hydrolysis, Hydrogenations and
Hydrations ............................................. 73
3.13 Conclusion ............................................. 78
Acknowledgements ............................................ 78
References .................................................. 79
4 Modern Alchemy: Replacing Precious Metals with Iron in
Catalytic Alkene and Carbonyl Hydrogenation Reactions ....... 83
Paul J. Chirik
4.1 Introduction ........................................... 83
4.2 Alkene Hydrogenation ................................... 86
4.2.1 Iron Carbonyl Complexes ......................... 86
4.2.2 Iron Phosphine Compounds ........................ 89
4.2.3 Bis(imino)pyridine Iron Complexes ............... 93
4.2.4 α-Diimine Iron Complexes ........................ 99
4.3 Carbonyl Hydrogenation ................................ 101
4.3.1 Hydrosilylation ................................ 101
4.3.2 Bifunctional Complexes ......................... 103
4.4 Outlook ............................................... 105
References ................................................. 106
5 Olefin Oligomerizations and Polymerizations Catalyzed by
Iron and Cobalt Complexes Bearing Bis(imino)pyridine
Ligands .................................................... 111
Vernon C. Gibson and Gregory A. Solan
5.1 Introduction .......................................... 111
5.2 Precatalyst Synthesis ................................. 112
5.2.1 Ligand Preparation ............................. 112
5.2.2 Complexation with MX2 (M = Fe, Co) ............. 113
5.3 Precatalyst Activation and Catalysis .................. 115
5.3.1 Olefin Polymerization .......................... 115
5.3.1.1 Catalytic Evaluation .................. 116
5.3.1.2 Steric Versus Electronic Effects ...... 116
5.3.1.3 Effect of MAO Concentration ........... 119
5.3.1.4 Effects of Pressure and Temperature ... 120
5.3.1.5 α-Olefm Monomers ...................... 121
5.3.2 Olefin Oligomerization ......................... 122
5.3.2.1 Catalytic Evaluation .................. 122
5.3.2.2 Substituent Effects ................... 122
5.3.2.3 Schulz-Flory Distributions ............ 124
5.3.2.4 Poisson Distributions ................. 124
5.3.2.5 α-Olefin Monomers ..................... 125
5.4 The Active Catalyst and Mechanism ..................... 125
5.4.1 Active Species ................................. 125
5.4.1.1 Iron Catalyst ......................... 126
5.4.1.2 Cobalt Catalyst ....................... 127
5.4.2 Propagation and Chain Transfer Pathways/
Theoretical Studies ............................ 127
5.4.3 Weil-Defined Iron and Cobalt Alkyls ............ 129
5.5 Other Applications .................................... 133
5.5.1 Immobilization ................................. 133
5.5.2 Reactor Blending and Tandem Catalysis .......... 134
5.6 Conclusions and Outlook ............................... 134
6 Cobalt and Nickel Catalyzed Reactions Involving C-H and
C-N Activation Reactions ................................... 143
Renee Becker and William D. Jones
6.1 Introduction .......................................... 143
6.2 Catalysis with Cobalt ................................. 143
6.3 Catalysis with Nickel ................................. 154
References ................................................. 163
7 A Modular Approach to the Development of Molecular
Electrocatalysts for H2 Oxidation and Production Based
on Inexpensive Metals ...................................... 165
M. Rakowski DuBois and Daniel L. DuBois
7.1 Introduction .......................................... 165
7.2 Concepts in Catalyst Design Based on Structural
Studies of Hydrogenase Enzymes ........................ 166
7.3 A Layered or Modular Approach to Catalyst Design ...... 170
7.4 Using the First Coordination Sphere to Control the
Energies of Catalytic Intermediates ................... 171
7.5 Using the Second Coordination Sphere to Control the
Movement of Protons between the Metal and the
Exterior of the Molecular Catalyst .................... 173
7.6 Integration of the First and Second Coordination
Spheres ............................................... 174
7.7 Summary ............................................... 178
Acknowledgements ........................................... 179
References ................................................. 179
8 Nickel-Catalyzed Reductive Couplings and Cyclizations ...... 181
Hasnain A. Malik, Ryan D. Baxter, and John Montgomery
8.1 Introduction .......................................... 181
8.2 Couplings of Alkynes with a,P-Unsaturated Carbonyls ... 182
8.2.1 Three-Component Couplings via Alkyl Group
Transfer-Methods Development ................... 182
8.2.2 Reductive Couplings via Hydrogen Atom
Transfer-Methods Development ................... 184
8.2.3 Mechanistic Insights ........................... 186
8.2.3.1 Metallacycle-Based Mechanistic
Pathway ............................... 186
8.2.4 Use in Natural Product Synthesis ............... 189
8.3 Couplings of Alkynes with Aldehydes ................... 191
8.3.1 Three-Component Couplings via Alkyl Group
Transfer-Method Development .................... 192
8.3.2 Reductive Couplings via Hydrogen Atom
Transfer-Method Development .................... 193
8.3.2.1 Simple Aldehyde and Alkyne
Reductive Couplings ................... 194
8.3.2.2 Directed Processes .................... 196
8.3.2.3 Diastereoselective Variants:
Transfer of Chirality ................. 197
8.3.2.4 Asymmetric Variants ................... 199
8.3.3 Mechanistic Insights ........................... 200
8.3.4 Cyclocondensations via Hydrogen Gas Extrusion .. 204
8.3.5 Use in Natural Product Synthesis ............... 205
8.4 Conclusions and Outlook ............................... 210
Acknowledgements ........................................... 210
References ................................................. 210
9 Copper-Catalyzed Ligand Promoted Ullmann-type Coupling
Reactions .................................................. 213
Yongwen Jiang and Dawei Ma
9.1 Introduction .......................................... 213
9.2 C-N Bond Formation .................................... 213
9.2.1 Arylation of Amines ............................ 213
9.2.1.1 Arylation of Aliphatic Primary and
Secondary Amines ...................... 223
9.2.1.2 Arylation of Aryl Amines .............. 215
9.2.1.3 Arylation of Ammonia .................. 215
9.2.2 Arylation and Vinylation of N-Heterocycles ..... 217
9.2.2.1 Coupling of Aryl Halides and
N-Heterocycles ........................ 217
9.2.2.2 Coupling of Vinyl Bromides and
N-Heterocycles ........................ 218
9.2.3 Aromatic Amidation ............................. 218
9.2.3.1 Cross-Coupling of aryl Halides with
Amides and Carbamates ................. 219
9.2.3.2 Cross-Coupling of Vinyl Halides with
Amides or Carbamates .................. 220
9.2.3.3 Cross-Coupling of Alkynl Halides
with Amides or Carbamates ............. 220
9.2.4 Azidation ...................................... 221
9.3 C-0 Bond Formation .................................... 222
9.3.1 Synthesis of Diaryl Ethers ..................... 222
9.3.2 Aryloxylation of Vinyl Halides ................. 223
9.3.3 Cross-Coupling of Aryl Halides with Aliphatic
Alcohols ....................................... 223
9.4 C-C Bond Formation .................................... 224
9.4.1 Cross-Coupling with Terminal Acetylene ......... 224
9.4.2 The Arylation of Activated Methylene
Compounds ...................................... 225
9.4.3 Cyanation ...................................... 227
9.5 C-S Bond Formation .................................... 228
9.5.1 The Formation of Bisaryl- and Arylalkyl-
Thioethers ..................................... 228
9.5.2 The Synthesis of Alkenylsulfides ............... 229
9.5.3 Assembly of aryl Sulfones ...................... 229
9.6 C-P Bond Formation .................................... 230
9.7 Conclusion ............................................ 230
References ................................................. 231
10 Copper-Catalyzed Azide-Alkyne Cycloaddition (CuAAC) ........ 235
M.G. Finn and Valery V. Fokin
10.1 Introduction .......................................... 235
10.2 Azide-Alkyne Cycloaddition: Basics .................... 237
10.3 Copper-Catalyzed Cycloadditions ....................... 238
10.3.1 Catalysts and Ligands .......................... 238
10.3.2 CuAAC with In Situ Generated Azides ............ 244
10.3.3 Mechanistic Aspects of the CuAAC ............... 244
10.3.4 Reactions of Sulfonyl Azides ................... 250
10.3.5 Copper-Catalyzed Reactions with Other Dipolar
Species ........................................ 251
10.3.6 Examples of Application of the CuAAC Reaction .. 252
10.3.6.1 Synthesis of Compound Libraries for
Biological Screening .................. 252
10.3.6.2 Copper-Binding Adhesives .............. 253
10.3.7 Representative Experimental Procedures ......... 255
Acknowledgements ........................................... 256
References ................................................. 257
11 "Frustrated Lewis Pairs": A Metal-Free Strategy for
Hydrogenation Catalysis .................................... 261
Douglas W. Stephan
11.1 Phosphine-Borane Activation of H2 ..................... 263
11.2 "Frustrated Lewis Pairs" .............................. 264
11.1 Metal-Free Catalytic Hydrogenation .................... 267
11.4 Future Considerations ................................. 273
Acknowledgements ........................................... 273
References ................................................. 273
Index ...................................................... 277
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