The design of ancillary ligands used to modify the structural and reactivity properties of metal complexes has evolved into a rapidly expanding sub-discipline in inorganic and organometallic chemistry. Ancillary ligand design has figured directly in the discovery of new bonding motifs and stoichiometric reactivity, as well as in the development of new catalytic protocols that have had widespread positive impact on chemical synthesis on benchtop and industrial scales.

Ligand Design in Metal Chemistry presents a collection of cutting-edge contributions from leaders in the field of ligand design, encompassing a broad spectrum of ancillary ligand classes and reactivity applications. Topics covered include:

• Key concepts in ligand design
• Redox non-innocent ligands
• Ligands for selective alkene metathesis
• Ligands in cross-coupling
• Ligand design in polymerization
• Ligand design in modern lanthanide chemistry
• Cooperative metal-ligand reactivity
• P,N Ligands for enantioselective hydrogenation
• Spiro-cyclic ligands in asymmetric catalysis

This book will be a valuable reference for academic researchers and industry practitioners working in the field of ligand design, as well as those who work in the many areas in which the impact of ancillary ligand design has proven significant, for example synthetic organic chemistry, catalysis, medicinal chemistry,  polymer science and materials chemistry.

Mark Stradiotto, Department of Chemistry, Dalhousie University, Canada
Rylan Lundgren, Department of Chemistry, University of Alberta, Canada
Both professors have a well-established track-record of working in the field of organometallic ligand design and catalysis, and have published extensively on the subjects of metal-catalyzed cross-coupling, novel transition-metal bond activation, and asymmetric catalysis. They are co-inventors of the now commercialized DalPhos ligand family and have broad experience of the  field of ligand design. Professor Stradiotto has worked in the field of organometallic chemistry for the past fourteen years. Professor Lundgren earned his PhD under the supervision of Prof Stradiotto at Dalhousie University in 2010. Following a PDF at MIT and Caltech with Prof. Greg Fu, Rylan accepted a faculty position at the University of Alberta (Canada).

List of Contributors xii

Foreword by Stephen L. Buchwald xiv

Foreword by David Milstein xvi

Preface xvii

1 Key Concepts in Ligand Design: An Introduction 1
Rylan J. Lundgren and Mark Stradiotto

1.1 Introduction 1

1.2 Covalent bond classification and elementary bonding concepts 2

1.3 Reactive versus ancillary ligands 4

1.4 Strong- and weak-field ligands 4

1.5 Trans effect 6

1.6 Tolman electronic parameter 6

1.7 Pearson acid base concept 8

1.8 Multidenticity, ligand bite angle, and hemilability 8

1.9 Quantifying ligand steric properties 10

1.10 Cooperative and redox non-innocent ligands 12

1.11 Conclusion 12

References 13

2 Catalyst Structure and Cis–Trans Selectivity in Ruthenium-based Olefin Metathesis 15
Brendan L. Quigley and Robert H. Grubbs

2.1 Introduction 15

2.2 Metathesis reactions and mechanism 17

2.3 Catalyst structure and E/Z selectivity 24

2.4 Z-selective Ru-based metathesis catalysts 33

2.5 Cyclometallated Z-selective metathesis catalysts 36

2.6 Conclusions and future outlook 42

References 43

3 Ligands for Iridium-catalyzed Asymmetric Hydrogenation of Challenging Substrates 46
Marc-André Müller and Andreas Pfaltz

3.1 Asymmetric hydrogenation 46

3.2 Iridium catalysts based on heterobidentate ligands 49

3.3 Mechanistic studies and derivation of a model for the enantioselective step 57

3.4 Conclusion 63

References 64

4 Spiro Ligands for Asymmetric Catalysis 66
Shou-Fei Zhu and Qi-Lin Zhou

4.1 Development of chiral spiro ligands 66

4.2 Asymmetric hydrogenation 73

4.3 Carbon–carbon bond-forming reactions 85

4.4 Carbon–heteroatom bond-forming reactions 91

4.5 Conclusion 98

References 98

5 Application of Sterically Demanding Phosphine Ligands in Palladium-Catalyzed Cross-Coupling leading to C(sp2)„ŸE Bond Formation (E = NH2 , OH, and F) 104
Mark Stradiotto and Rylan J. Lundgren

5.1 Introduction 104

5.2 Palladium-catalyzed selective monoarylation of ammonia 108

5.3 Palladium-catalyzed selective hydroxylation of (hetero)aryl halides 117

5.4 Palladium-catalyzed nucleophilic fluorination of (hetero)aryl (pseudo)halides 123

5.5 Conclusions and outlook 129

Acknowledgments 130

References 131

6 Pd-N-Heterocyclic Carbene Complexes in Cross-Coupling Applications 134
Jennifer Lyn Farmer, Matthew Pompeo, and Michael G. Organ

6.1 Introduction 134

6.2 N-heterocyclic carbenes as ligands for catalysis 135

6.3 The relationship between N-heterocyclic carbene structure and reactivity 136

6.4 Cross-coupling reactions leading to C„ŸC bonds that proceed through transmetalation 140

6.5 Kumada–Tamao–Corriu 141

6.6 Suzuki–Miyaura 148

6.7 Negishi coupling 163

6.8 Conclusion 170

References 171

7 Redox Non-innocent Ligands: Reactivity and Catalysis 176
Bas de Bruin, Pauline Gualco, and Nanda D. Paul

7.1 Introduction 176

7.2 Strategy I. Redox non-innocent ligands used to modify the Lewis acid–base properties of the metal 179

7.3 Strategy II. Redox non-innocent ligands as electron reservoirs 181

7.4 Strategy III. Cooperative ligand-centered reactivity based on redox active ligands 192

7.5 Strategy IV. Cooperative substrate-centered radical-type reactivity based on redox non-innocent substrates 195

7.6 Conclusion 200

References 201

8 Ligands for Iron-based Homogeneous Catalysts for the Asymmetric Hydrogenation of Ketones and Imines 205
Demyan E. Prokopchuk, Samantha A. M. Smith, and Robert H. Morris

8.1 Introduction: from ligands for ruthenium to ligands for iron 205

8.2 First generation iron catalysts with symmetrical [6.5.6--P-N-N-P ligands 216

8.3 Second generation iron catalysts with symmetrical [5.5.5--P-N-N-P ligands 220

8.4 Third generation iron catalysts with unsymmetrical [5.5.5--P-NH-N-Pʹ ligands 227

8.5 Conclusions 231

Acknowledgments 232

References 232

9 Ambiphilic Ligands: Unusual Coordination and Reactivity Arising from Lewis Acid Moieties 237
Ghenwa Bouhadir and Didier Bourissou

9.1 Introduction 237

9.2 Design and structure of ambiphilic ligands 238

9.3 Coordination of ambiphilic ligands 242

9.4 Reactivity of metallic complexes deriving from ambiphilic ligands 251

9.5 Conclusions and outlook 264

References 266

10 Ligand Design in Enantioselective Ring-opening Polymerization of Lactide 270
Kimberly M. Osten, Dinesh C. Aluthge, and Parisa Mehrkhodavandi

10.1 Introduction 270

10.2 Indium and zinc complexes bearing chiral diaminophenolate ligands 292

10.3 Dinuclear indium complexes bearing chiral salen-type ligands 297

10.4 Conclusions and future directions 301

References 302

11 Modern Applications of Trispyrazolylborate Ligands in Coinage Metal Catalysis 308
Ana Caballero, M. Mar Díaz-Requejo, Manuel R. Fructos, Juan Urbano, and Pedro J. Pérez

11.1 Introduction 308

11.2 Trispyrazolylborate ligands: main features 310

11.3 Catalytic systems based on Tpx ML complexes (M=Cu, Ag) 311

11.4 Conclusions 326

Acknowledgments 326

References 327

12 Ligand Design in Modern Lanthanide Chemistry 330
David P. Mills and Stephen T. Liddle

12.1 Introduction and scope of the review 330

12.2 C-donor ligands 333

12.3 N-donor ligands 344

12.4 P-donor ligands 349

12.5 Multiple bonds 350

12.6 Conclusions 356

Notes 357

References 357

13 Tight Bite Angle N,O-Chelates. Amidates, Ureates and Beyond 364
Scott A. Ryken, Philippa R. Payne, and Laurel L. Schafer

13.1 Introduction 364

13.2 Applications in reactivity and catalysis 377

13.3 Conclusions 400

References 401

Index 406