Metallocenes Volume 2 Synthesis Reactivity Applications Edited by Antonio Togni and Ronald L. Halterman WILEY-VCH Weinheim New York Chichester Brisbane Singapore Toronto /
Preface V Volume 1 Synthesis and Reactivity 1 Main Group Metallocenes P. Jutzi and N. Burford 1.1 Abstract 3 1.2 Introduction 3 1.3 Synthetic Procedures 5 1.3.1 Reactions Involving Cyclopentadienes 6 1.3.2 Salt Metathesis Reactions 6 1.3.3 Disproportionation, Comproportionation and Decomposition 7 1.3.4 Halide Ion Abstraction 7 1.3.5 Substitution onto the Cp Ligand Frame 7 1.3.6 Reduction 7 1.3.7 Addition of Cp Anions 8 1.4 Characterization Features 8 1.5 Structural Types 10 1.5.1 Sandwich Complexes 11 1.5.2 Half Sandwich Complexes 12 1.5.3 /i-rc-cyclopentadienyl Molecular Complexes 13 1.5.4 ju-rc-cyclopentadienyl Super-Sandwich Polymers 14 1.5.5 Dimers 15 1.5.6 Clusters 16 1.6 Cp-Element Orbital Interactions 18 1.6.1 Orbital Interaction Model for Half Sandwich Complexes 18 1.6.2 Orbital Interaction Model for Sandwich Complexes 20 1.7 Metallocenes of the Alkali Metals 23 /
VI Contents 1.7.1 Monomers and Polymers 23 1.7.2 Lithocene and Sodocene Anions 27 1.8 Metallocenes of the Alkaline Earth Metals 28 1.8.1 Beryllocene 29 1.8.2 Alkaline Earth Sandwich Metallocenes 29 1.8.3 Half Sandwich Metallocenes of the Group 2 Elements 32 1.9 Metallocenes of the Group 13 Elements 33 1.9.1 Half Sandwich Monomers, Dimers, Oligomers and Polymers 33 1.9.2 Clusters 34 1.9.3 Metallocenes Involving Group 13 Elements in Oxidation State in... 35 1.9.4 Heteroatom Clusters 36 1.10 Metallocenes of the Group 14 Elements 36 1.10.1 Group 14 Sandwich Complexes 36 1.10.2 Half Sandwich Complexes of Group 14 Elements 39 1.10.3 Tricyclopentadienyl Complexes 40 1.10.4 Reaction Chemistry 40 1.11 Metallocenes of the Pnictogens 41 1.12 Factors Governing the Structure of Multicyclopentadienyl Complexes 44 1.13 Conclusions 46 1.14 Acknowledgments 46 References 47 2 Lanthanocenes F. T. Edelmann 2.1 Introduction. 55 2.2 Lanthanide(II) Metallocenes 55 2.3 Lanthanide(III) Metallocenes 62 2.3.1 Lanthanide(III) Metallocenes Containing Ln-Group 17 Element Bonds 62 2.3.2 Lanthanide(III) Metallocenes Containing Ln-Group 16 Element Bonds 69 2.3.3 Lanthanide(III) Metallocenes Containing Ln-Group 15 Element Bonds 75 2.3.4 Lanthanide(III) Metallocenes Containing Ln-Group 14 Element Bonds 80 2.3.5 Lanthanide(III) Metallocenes Containing Ln-Hydrogen Bonds 94 2.4 Conclusion and Perspective 102 2.5 Acknowledgments 104 References 104
VII 3 Group 3 Metallocenes P. J. Chirik and J. E. Bercaw 3.1 Introduction 111 3.2 Synthesis of Group 3 Metallocenes 112 3.2.1 Scandium 112 3.2.2 Yttrium and Lanthanum 116 3.3 Group 3 Metallocenes for the Activation of Hydrocarbons 124 3.4 Group 3 Metallocenes as Homogeneous Olefin Polymerization Catalysts 126 3.5 Reactions of Group 3 Metallocenes with Acetylenes 133 3.6 Reactions of Group 3 Metallocenes with Group 6 Compounds 135 3.7 Reactions of Group 3 Metallocenes with Other Small Molecules... 136 3.8 Applications of Group 3 Metallocenes in Organic Synthesis 142 3.9 Photophysics of Group 3 Metallocenes 145 3.10 Alternatives of Cyclopentadienyl Ligands 146 3.11 Concluding Remarks 147 References 148 4 Titanocenes R. Beckhaus 4.1 Introduction 153 4.1.1 Bonding Modes of Cyclopentadienyl Ligands in Titanium Complexes. 154 4.1.2 Synthesis of Titanocene Complexes 154 4.1.3 Sources of the Titanocene Fragment as a Versatile Building Block.. 157 4.2 Electronic Properties of Titanocenes 158 4.2.1 Titanocene Complexes in Low Oxidation States 159 4.2.2 Substituents on the Cp Rings 161 4.3 Ligands in the Coordination Sphere of Titanocenes 162 4.3.1 Olefins 162 4.3.2 Acetylenes 162 4.3.3 Carbonyls 165 4.3.4 Phosphines 166 4.3.5 Hydrides 166 4.3.6 Titanium Ligand Multiple Bonds 167 4.3.6.1 Carbene Complexes 167 4.3.6.2 Complexes Containing Ti-X Double Bonds (X: N, P, Chalcogenides) 171 4.3.7 Metallocene Complexes of the Type [Cp 2 TiL 2 ] 2+ 173
4.3.7.1 Aqua-Titanocene Complexe 173 4.3.7.2 Titanocene Complexes with Highly Fluorinated Ligand Systems... 174 4.3.7.3 Further Complexes with [Titanocene] 2 " 1 " (d ) and [Titanocene]" 1 " (d 1 ) Units 174 4.4 Reactions in the Coordination Sphere of Titanocenes 175 4.4.1 The free Titanocenes 175 4.4.2 Reactions of Ti-C a Bonds 178 4.4.2.1 Reductive Elimination 179 4.4.2.2 Oxidative Addition 180 4.4.2.3 a-h Elimination 181 4.4.2.4 ß-U Elimination 184 4.4.3 Reactions of Ti=C Double Bonds 185 4.4.3.1 Reactions with Electrophiles 186 4.4.3.2 C-H Activation Reactions on [L n Ti=C] Fragments 187 4.4.3.3 [2+1] Additions 187 4.4.3.4 Cycloaddition Reactions with Acetylenes 188 4.4.3.5 Synthesis and Reactivity of Metallaoxetanes 191 4.4.3.6 Synthesis of Heterodinuclear Carbene Complexes with a Titanaoxetane Substructure 193 4.4.3.7 Synthesis and Reactivity of Heterotitanacyclobutenes and-butanes. 196 4.4.3.8 Structure and Reactivity Pattern for small Titanacycles 200 4.4.3.9 Dimetallic Compounds Derived from Ti=C Species 205 4.4.4 Reactions Involving the Cp Ligand 209 4.5 Analytical Data 210 4.5.1 Structural Data 210 4.5.2 NMR Data 212 4.5.2.1 l H NMR Data 212 4.5.2.2 13 C NMR Data 213 4.5.2.3 Ti NMR Data 214 4.5.3 UV vis Spectra 215 4.6 Selected Applications of Titanocene Complexes 217 4.6.1 C-C Coupling Reactions 217 4.6.1.1 Dimerization of Ethylene 217 4.6.1.2 Head to Tail Coupling Reactions of Acetylenes 218 4.6.1.3 Cyclization Reactions 219 4.6.2 Stoichiometric and Catalytic Reactions of Carbenoid Metal Complexes of Electron-Deficient Transition Metals 220 4.6.2.1 Carbonyl Olefinations with Tebbe, Grubbs, and Petasis Reagents... 220 4.6.2.2 Ene Reactions 223 4.6.2.3 Catalytic Reactions 224 4.7 Cp-Equivalents 226 4.8 Acknowledgments 230 References 230
IX 5 Zirconocenes E. Negishi andj.-l. Montchamp 5.1 Introduction 241 5.2 Preparation of Cp 2 Zr Compounds 246 5.2.1 Transmetallation 246 5.2.2 Hydrozirconation 249 5.2.3 Oxidative Addition 254 5.2.4 Oxidative Coupling and Complexation 255 5.3 Reactions and Synthetic Applications of Monoorganylzirconocene Derivatives 261 5.3.1 Protonolysis, Halogenolysis, Oxidation, and Related Carbon-Heteroatom Bond Formation Reactions 262 5.3.1.1 Protonolysis and Deuterolysis 262 5.3.1.2 Halogenolysis 262 5.3.1.3 Oxidation 264 5.3.2 Carbon-Carbon Bond Formation via Polar Reactions of RZrCp 2 Cl with Carbon Electrophiles 264 5.3.2.1 Reactions of Allylzirconocenes with Aldehydes 264 5.3.2.2 Reactions of Cationic Alkyl- and Alkenylzirconocenes with Aldehydes, Epoxides, Ketones, and Nitriles 266 5.3.3 Carbon-Carbon Bond Formation via Migratory Insertion Reactions of RZrCp 2 Cl 267 5.3.3.1 Carbonylation 268 5.3.3.2 Isonitrile Insertion 269 5.3.3.3 Other Migratory Insertion Reactions 269 5.3.4 Stoichiometric Carbozirconation of Monoorganylzirconocenes 270 5.3.5 Reactions of Monoorganylzirconocenes via Transmetallation 271 5.3.5.1 Stoichiometric Conversion of Monoorganylzirconocenes into Other Organometals 272 5.3.5.2 Reactions of Monoorganylzirconocenes Catalyzed by Metal Complexes 274 5.3.6 Organometallic Reactions Catalyzed by Zirconocene Derivatives... 276 5.3.6.1 Zirconium-Catalyzed Carboalumination and Carbozincation of Alkynes 276 5.3.6.2 Zirconium-Catalyzed Hydroalumination and Hydroboration of Alkenes and Alkynes 279 5.3.6.3 Zirconium-Catalyzed Enantioselective Carboalumination of Alkenes 280 5.4 Reactions Involving n-complexes of Zirconocenes or Three- Membered Zirconacycles 283 5.4.1 Formation of n-complexes of Zirconocenes 284
X Contents 5.4.2 Stoichiometric Reactions of 71-Complexes of Zirconocenes (or Three-Membered Zirconacycles) 288 5.4.2.1 Protonolysis and Halogenolysis 288 5.4.2.2 Ring Expansion Reactions 289 5.4.2.3 Regioisomerization, Stereoisomerization, cr-bond Metathesis, and Other Stoichiometric Reactions of Three-Membered Zirconacycles 294 5.4.3 Stoichiometric Reactions of Five-Membered Zirconacycles 296 5.4.4 Catalytic Reactions Involving Zirconacycles and Related Derivatives 299 5.4.4.1 Zirconium-Catalyzed Carbomagnesiation Reactions Involving C-H Activation 300 5.4.4.2 Zirconium-Catalyzed Carboalumination of Alkynes via C-H Activation 304 5.4.4.3 Other Zirconium-Catalyzed Reactions Involving Cp 2 Zr(II) Complexes 308 5.5 Conclusion 310 References 312 6 Group 5 and Group 6 Metallocenes P. Royo and E. Ryan 6.1 Introduction 321 6.2 Type A Metallocene Compounds 322 6.2.1 Neutral Metallocenes 323 6.2.1.1 Group 5 Metallocenes [MCp 2 ] 323 6.2.1.2 Group 6 Metallocenes [MCp 2 ] 326 6.2.2 Ionic Mettalocenes 329 6.2.2.1 Group 5 Cationic Metallocenes [MCp 2 ] + 329 6.2.2.2 Group 5 Anionic Metallocenes [MCp 2 ]" 330 6.2.2.3 Group 6 Cationic Metallocenes [MCp 2 ] + 330 6.2.2.4 Group 6 Anionic Metallocenes [MCp 2 ]' 330 6.3 Type B-Bent bis(cyclopentadienyl) Metal Complexes with Mono-Functional Single-Atom Donor Monoanionic and Neutral Ligands 331 6.3.1 Complexes with One Coordinated Ligand 331 6.3.1.1 Neutral Group 6 [MCp 2 L] Metal Complexes 333 6.3.1.2 Anionic Group 5 [MCp 2 L]" and Group 6 [MCp 2 X]" Metal Complexes 334 6.3.1.3 Neutral Group 5 [MCp 2 L] and Group 6 [MCp 2 X] Metal Complexes 336
XI 6.3.1.4 Anionic Group 5 [MCp2X]- and Cationic Group 6 [MCp 2 L] + Metal Complexes 339 6.3.1.5 Neutral d 2 Vanadium Compounds [VCp 2 X] 340 6.3.1.6 Neutral d 2 Niobium and Tantalum Compounds [(Nb,Ta)Cp 2 X] 344 6.3.1.7 Cationic Group 5 d 2 Metal Compounds [MCp 2 L] + 345 6.3.1.8 Cationic Group 6 d 2 Metal Compounds [MCp 2 X] + 346 6.3.2 Complexes with Two Coordinated Ligands 346 6.3.2.1 Neutral Group 5 d 2 Metal Compounds [MCp 2 XL] 348 6.3.2.2 Cationic Group 5 d 2 Metal Compounds [MCp 2 L 2 ] + 356 6.3.2.3 Anionic Group 5 d 2 Metal Compounds [MCp 2 X 2 ]" 357 6.3.2.4 Neutral Group 6 d 2 Metal Compounds [MCp 2 X 2 ] 359 6.3.2.5 Cationic Group 6 d 2 Metal Compounds [MCp 2 XL] + 365 6.3.2.6 Dicationic Group 6 d 2 Metal Compounds [MCp 2 L 2 ] 2+ 367 6.3.2.7 Neutral Group 5 d 1 Metal Compounds [MCp 2 X 2 ] 368 6.3.2.8 Cationic Group 5 d 1 Metal Compounds [MCp 2 XL] +, [MCp 2 L 2 ] 2+... 371 6.3.2.9 Cationic Group 6 d 1 Metal Compounds [MCp 2 X 2 ] + 371 6.3.2.10 Cationic Group 5 d Metal Compounds [MCp 2 X 2 ] +, [MCp 2 XL] 2+... 372 6.3.2.11 Dicationic Group 6 d Metal Compounds [MCp 2 X 2 ] 2+ 373 6.3.3 Complexes with Three Coordinated Ligands 374 6.3.3.1 Neutral Group 5 d Metal Compounds [MCp 2 X 3 ] 375 6.3.3.2 Cationic Group 5 d Metal Compounds [MCp 2 X 2 L] +, [MCp 2 XL 2 ] 2+ and [MCp 2 L 3 ] 3+ 377 6.3.3.3 Cationic Group 6 d Metal Compounds [MCp 2 X 3 ] + 378 6.4 Type C - Complexes with Single-Atom Donor Dianionic Ligands... 378 6.4.1 18-Electron Compounds 378 6.4.1.1 Neutral Group 5 d Metal Compounds [MCp 2 EX] 379 6.4.1.2 Cationic Group 5 d Metal Compounds[MCp 2 EL] + 387 6.4.1.3 Neutral Group 6 d 2 Metal Compounds [MCp 2 E] 387 6.4.1.4 Cationic Group 6 d Metal Compounds [MCp 2 EX] + 389 6.4.2 17-Electron Compounds 389 6.4.2.1 Neutral d 1 Vanadium Compounds [VCp 2 E] 389 6.5 Type D-Complexes with J7 2 -Side-Bonded Ligands 390 6.5.1 18-Electron Compounds 390 6.5.1.1 Neutral Group 5 d 2 Metal Compounds [MCp 2 (r7 2 -X-L)] 390 6.5.1.2 Neutral Group 5 Metal Complexes [MCp 2 X(?7 2 -C-C)] or [MCp 2 X(?7 2 -C-Y)] (Y = N, O, or S) 391 6.5.1.3 Anionic Group 5 d 2 Metal Compounds [MCp 2 (?7 2 -C,Y)] + and [MCp 2 X(77 2 -C,Y)]- 398 6.5.1.4 Neutral Group 6 d 2 Metal Compounds [MCp 2 (r7 2 -X-X)] 398 6.5.1.5 Cationic Group 6 d 2 Metal Compounds [MCp 2 (?7 2 -X-L)] + 399 6.5.1.6 Neutral Group 5 d Metal Compounds [MCp 2 (?7 2 -X-X)Z] 400 6.5.1.7 Cationic Group 5 d Metal Compounds [MCp^L]* and [MCp 2 (?7 2 -X-L)Z] + 401
6.5.2 17-Electron Compounds 403 6.5.2.1 Neutral d 1 Vanadium Compounds [VCp 2 (r? 2 -X-X)] 403 6.5.2.2 Niobium Compounds [NbCp 2 (T7 2 -L-L)] and [NbCp 2 (T7 2 -C,Y)] 404 References 405 7 Half-Sandwich Complexes as Metallocene Analogs J. Okuda and T. Eberle 7.1 Introduction 415 7.2 Complexes with Linked Amido-Cyclopentadienyl Ligands 417 7.2.1 Synthesis 417 7.2.2 Hydrido and Alkyl Complexes 424 7.2.3 Reactivity 429 7.2.4 Structure 431 7.3 Complexes with Polydentate Amido-Cyclopentadienyl Ligands... 435 7.4 Complexes with two Amido-Cyclopentadienyl Ligands 440 7.5 Complexes with Linked Alkoxo-Cyclopentadienyl Ligands 443 7.6 Catalysis 445 7.6.1 Polymerization of Ethylene, a-olefins and Dienes 445 7.6.2 Hydrogenation and Hydroboration 449 7.7 Conclusion 450 References 450 8 Synthesis of Chirai Titanocene and Zirconocene Dichlorides R. L. Halterman 8.1 Introduction 455 8.2 Ligand Chirality and Stereoisomeric Metal Complexes 456 8.3 Unbridged Ligands 469 8.3.1 Cyclopentadienes 469 8.3.2 Indenes 484 8.4 Bridged Ligands with Nonstereogenic Bridging Groups 491 8.4.1 Bis(cyclopentadienes) 491 8.4.2 Bis(indenes) 497 8.4.3 Bis(fluorenes) 502 8.4.4 Mixed Ligands 502 8.5 Bridged Ligands with Stereogenic Bridging Groups 506 8.6 Unbridged Metal Complexes 513 8.6.1 Bis(cyclopentadienyl)metals 513
XIII 8.6.2 Bis(indenes) 518 8.6.3 Bis(fluorenes) 520 8.6.4 Mixed Ligands 521 8.7 Metal Complexes with Nonstereogenic Bridging Groups 522 8.7.1 Bis(cyclopentadienyl)metals 522 8.7.2 Bis(indenes) 527 8.7.3 Bis(fluorenes) 530 8.7.4 Mixed Ligands 530 8.8 Metal Complexes with Stereogenic Bridging Groups 531 References 539