Table of Contents
Preface xiii
1 Introduction to Early Main Group Organometallic Chemistry and Catalysis 1
Sjoerd Harder
1.1 Introduction 1
1.2 s-Block Organometallics 1
1.2.1 Short History 1
1.2.2 Synthesis of Group 1 Organometallics 2
1.2.3 Synthesis of Group 2 Organometallics 4
1.2.4 Bonding and Structures of s-Block Organometallics 8
1.2.5 Dynamics of s-Block Organometallics in Solution 13
1.2.6 Low-Valent s-Block Chemistry 16
1.3 s-Block Organometallics in Catalysis 17
1.3.1 Working Principles in Lewis Acid Catalysis 17
1.3.2 Working Principles in s-Block Organometallic Catalysis 19
1.3.3 Substrate Activation by s-Block Metals 21
1.3.4 Future of Early Main Group Metal Catalysis 23
List of Abbreviations 24
References 24
2 Polymerization of Alkenes and Polar Monomers by Early Main Group Metal Complexes 31
Sjoerd Harder
2.1 Introduction 31
2.2 Alkene Polymerization 32
2.2.1 Styrene Polymerization 33
2.2.2 Polymerization of Modified Styrene 40
2.2.3 Polymerization of Butadiene or Isoprene 43
2.3 Polymerization of Polar Monomers 45
2.3.1 Polymerization of Lactides 45
2.3.2 Copolymerization of Epoxides and CO2 50
2.4 Conclusions 53
List of Abbreviations 54
References 54
3 Intramolecular Hydroamination of Alkenes 59
Sebastian Bestgen and Peter W. Roesky
3.1 Introduction 59
3.2 Hydroamination 60
3.2.1 Scope 62
3.3 s-Block Metal Catalysis 64
3.3.1 General Remarks 64
3.3.2 Mechanistic Aspects 65
3.3.3 Group 1-Based Catalysis 68
3.3.3.1 Concerted Reaction 68
3.3.3.2 Radical-Mediated Intramolecular Hydroamination 71
3.3.3.3 Reactions of N-Arylhydrazones and Ketoximes 72
3.3.4 Group 2 Metal-Mediated Catalysis 74
3.3.5 Group 2-Mediated Asymmetric Cyclohydroamination 83
3.3.6 Lewis Acidic Metal Cation Catalysis 84
3.3.7 Miscellaneous 85
3.4 Outlook 86
Acknowledgments 87
List of Abbreviations 87
References 88
4 Molecular s-Block Catalysts for Alkene Hydrophosphination and Related Reactions 93
Yann Sarazin and Jean-François Carpentier
4.1 Introduction 93
4.2 General Considerations 95
4.3 Hydrophosphination of Alkenes 96
4.3.1 Precatalysts with Nitrogen-Based Ligands 97
4.3.2 Precatalysts with Oxygen-Based Ligands 110
4.4 Hydrophosphination of Carbodiimides 112
4.5 Miscellaneous Reactions 114
4.5.1 Hydrophosphinylation of Alkenes and Enones 114
4.5.2 Hydrophosphonylation of Aldehydes and Ketones 116
4.6 Summary and Conclusions 117
List of Abbreviations 118
References 118
5 H - Nand H - P Bond Addition to Alkynes and Heterocumulenes 123
Sven Krieck and Matthias Westerhausen
5.1 Introduction 123
5.2 Hydroamination 124
5.2.1 Hydroamination with Secondary Amines 125
5.2.2 Hydroamination with Primary Amines 128
5.2.3 Proposed Mechanisms for the Hydroamination of Butadiynes 130
5.3 Hydrophosphanylation (Hydrophosphination) 134
5.4 Hydrophosphorylation and Hydrophosphonylation 138
5.5 Summary and Conclusions 143
5.6 Acknowledgments 146
5.7 Abbreviations 146
References 146
6 Early Main Group Metal-Catalyzed Hydrosilylation of Unsaturated Bonds 151
Sjoerd Harder
6.1 Introduction 151
6.2 Historical Development 151
6.3 Nonprecious Metal Hydrosilylation Catalysts 153
6.4 C=C Bond Hydrosilylation with s-Block Metal Catalysts 155
6.5 C=O Bond Hydrosilylation with s-Block Metal Catalysts 161
6.6 C=N Bond Hydrosilylation with s-Block Metal Catalysts 167
6.7 Conclusions 170
References 171
7 Early Main Group Metal Catalyzed Hydrogenation 175
Heiko Bauer and Sjoerd Harder
7.1 Introduction 175
7.2 Hydrogenation of C=C Double Bonds 178
7.3 Hydrogenation of C=N Double Bonds 187
7.4 Hydrogenation of C=O Double Bonds 191
7.5 Summary and Perspectives 194
References 197
8 Alkali and Alkaline Earth Element-Catalyzed Hydroboration Reactions 201
Aaron D. Sadow
8.1 Introduction and Overview 201
8.2 Thermodynamic Considerations 203
8.2.1 Hydroboration, Hydrosilylation, and Hydrogenation 203
8.2.2 Thermochemistry of Metal-Oxygen Bonds and Element-Hydrogen Bonds 205
8.3 Group 1-Catalyzed Hydroboration Reactions 207
8.3.1 Overview 207
8.3.2 Base-Catalyzed Hydroborations 207
8.3.3 Alkali Metal Hydridoborate and Aluminate-Catalyzed Hydroboration 210
8.4 Group 2-Catalyzed Hydroboration Reactions 214
8.4.1 Overview 214
8.4.2 β-Diketiminate Magnesium-Catalyzed Hydroborations 215
8.4.3 Tris(4,4-dimethyl-2-oxazolinyl)phenylborato Magnesium-Catalyzed Hydroboration of Ester and Amides 217
8.4.4 Magnesium Triphenylborate-Catalyzed Hydroboration 221
8.4.5 Supported Catalysts for Hydroboration 221
8.5 Summary and Conclusions 222
References 222
9 Dehydrocoupling and Other Cross-couplings 225
Merle Arrowsmith
9.1 Introduction 225
9.2 Early Main Group-Catalyzed Cross-DHC of Amines and Boranes 228
9.2.1 Early Stoichiometric Studies with s-Block Elements 228
9.2.2 s-Block-Catalyzed Cross-dehydrogenative Synthesis of Diaminoboranes 229
9.2.3 s-Block-Catalyzed DHC of DMAB 231
9.2.4 Calcium-Catalyzed Dehydrocoupling of tert-Butylamine Borane 235
9.2.5 s-Block-Catalyzed DHC of Amines and Monohydroboranes 235
9.3 s-Block-Catalyzed Cross-DHC of Amines and Silanes 238
9.3.1 Influence of Precatalysts and Substrates on Reactivity and Selectivity 238
9.3.2 Mechanistic and Computational Analysis 240
9.3.3 Application to the Synthesis of Oligo- and Polysilazanes 242
9.4 Other s-Block-Catalyzed Cross-DHC Reactions 243
9.4.1 Alkali Metal-Catalyzed DHC of Si - H and O - H Bonds 243
9.4.2 s-Block-Catalyzed DHC of Si - H and C - H Bonds 243
9.5 Early Main Group-Mediated Nondehydrogenative Cross-couplings 244
9.6 Conclusion and Outlook 245
References 246
10 Enantioselective Catalysis with s-Block Organometallics 251
Philipp Stegner and Sjoerd Harder
10.1 Introduction 251
10.2 Lithium-Based Catalysts 252
10.2.1 Lithium Catalysts Based on Neutral Chiral Ligands 252
10.2.2 Lithium Catalysts Based on Monoanionic Chiral Ligands 255
10.2.3 Lithium Catalysts Based on Dianionic Chiral Ligands 257
10.3 Potassium-Based Catalysts 259
10.3.1 Potassium Catalysts Based on Monoanionic Chiral Ligands 260
10.4 Magnesium-Based Catalysts 262
10.4.1 Magnesium Catalysts Based on Monoanionic Chiral Ligands 263
10.4.2 Magnesium Catalysts Based on Dianionic Chiral Ligands 266
10.5 Calcium-Based Catalysts 269
10.5.1 Calcium Catalysts Based on Monoanionic Chiral Ligands 269
10.5.2 Calcium Catalysts Based on Dianionic Chiral Ligands 273
10.6 Conclusion and Outlook 275
List of Abbreviations 275
References 276
11 Early Main Group Metal Lewis Acid Catalysis 279
Marian Rauser, Sebastian Schröder, and Meike Niggemann
11.1 Introduction 279
11.1.1 Lewis Acidity of s-Block Metal Cations 280
11.1.2 Interactions with More than One Lewis Base 281
11.1.3 Counter Anions 282
11.1.4 Solvation 283
11.1.5 Solubility and Aggregation 283
11.1.6 Water Tolerance 284
11.1.7 Relative Lewis Acid Activity of Alkaline and Alkaline Earth Metals 285
11.1.8 Hidden Brønsted Acid 287
11.2 Polarized Carbon-Heteroatom Double Bonds 287
11.2.1 Carboxylates: Anhydrides and Carbonates 288
11.2.2 Aldehydes, Ketones, and Formates 289
11.2.3 α,β-Unsaturated Carbonyl Compounds 291
11.2.4 Imines and Enamines 292
11.2.5 Mannich Reactions 294
11.2.6 Oxidation and Reduction 294
11.2.7 Donor-Acceptor Cyclopropanes 294
11.2.8 Diels-Alder Reaction and Cycloaddition 295
11.3 Activation of Polarized Single Bonds 296
11.3.1 Opening of Three-Membered Heterocycles 296
11.3.2 Leaving Groups 297
11.3.3 Ca2+-Catalyzed Dehydroxylation as a Special Case 299
11.4 Activation of Unpolarized Double Bonds 305
11.5 Summary and Conclusions 307
References 307
12 Enantioselective Group 2Metal Lewis Acid Catalysis 311
Yasuhiro Yamashita, Tetsu Tsubogo, and Shū Kobayashi
12.1 Introduction 311
12.2 Catalytic Enantioselective Reactions Using Chiral Magnesium Complexes 313
12.2.1 Chiral Magnesium-Catalyzed Diels-Alder and 1,3-Dipolar Cycloaddition Reactions 313
12.2.2 Chiral Magnesium-Catalyzed 1,4-Addition Reactions 315
12.2.3 Chiral Magnesium-Catalyzed Addition Reactions to Carbonyl Compounds 318
12.2.4 Chiral Magnesium-Catalyzed Addition Reactions with Imines 319
12.2.5 Chiral Magnesium-Catalyzed Ring-Opening Reactions of Epoxide and Aziridine 321
12.2.6 Chiral Magnesium-Catalyzed α-Functionalization Reactions of Carbonyl Compounds 323
12.2.7 Various Chiral Magnesium-Catalyzed Reactions 324
12.3 Catalytic Enantioselective Reactions Using Chiral Calcium Complexes 324
12.3.1 Chiral Calcium-Catalyzed Addition Reactions to Carbonyl Compounds 324
12.3.2 Chiral Calcium-Catalyzed 1,4-Addition Reactions 326
12.3.3 Chiral Calcium-Catalyzed Addition Reactions with Imines 331
12.3.4 Chiral Calcium-Catalyzed α-Functionalization Reactions with Carbonyl Compounds 333
12.3.5 Chiral Calcium-Catalyzed Cycloaddition Reactions 334
12.3.6 Chiral Calcium-Catalyzed Hydroamination Reactions 334
12.3.7 Chiral Calcium-Catalyzed Epoxidation Reactions 336
12.3.8 Chiral Calcium-Catalyzed Aziridine Ring-Opening Reaction 337
12.4 Catalytic Enantioselective Reactions Using Chiral Strontium Complexes 337
12.4.1 Chiral Strontium-Catalyzed 1,4-Addition Reactions 337
12.4.2 Chiral Strontium-Catalyzed Addition Reactions with Imines 338
12.4.3 Chiral Strontium-Catalyzed Oxime Formation 339
12.5 Catalytic Enantioselective Reactions Using Chiral Barium Complexes 339
12.5.1 Chiral Barium-Catalyzed Addition Reactions to Carbonyl Compounds and Imines 339
12.5.2 Chiral Barium-Catalyzed 1,4-Addition Reactions 340
12.5.3 Chiral Barium-Catalyzed Diels-Alder Reactions 341
12.6 Summary and Outlook 341
References 342
13 Miscellaneous Reactions 347
Michael S. Hill
13.1 Introduction 347
13.2 Privileged Substrates and s-Block Reactivity 347
13.3 Reactivity with Multiply Bonded Substrates 351
13.3.1 Tishchenko Dimerization of Aldehydes 351
13.3.2 Trimerization of Organic Isocyanates 352
13.3.3 Hydroalkoxylation of Alkynyl Alcohols 353
13.3.4 Catalytic Isomerization and C-C Coupling with Terminal Alkynes 354
13.3.5 Activation and Deoxygenation of C - O Multiple Bonds 358
13.4 Single-Electron Transfer Steps in s-Block-Centered Catalysis 361
13.5 “Beyond” Hydrofunctionalization and Dehydrocoupling 363
13.6 Conclusions and Conjecture 365
References 367
Index 373
