Over the last 60 years the increasing knowledge of transition metal chemistry has resulted in an enormous advance of homogeneous catalysis as an essential tool in both academic and industrial fields. Remarkably, phosphorus(III) donor ligands have played an important role in several of the acknowledged catalytic reactions. The positive effects of phosphine ligands in transition metal homogeneous catalysis have contributed largely to the evolution of the field into an indispensable tool in organic synthesis and the industrial production of chemicals. This book aims to address the design and…mehr
Over the last 60 years the increasing knowledge of transition metal chemistry has resulted in an enormous advance of homogeneous catalysis as an essential tool in both academic and industrial fields. Remarkably, phosphorus(III) donor ligands have played an important role in several of the acknowledged catalytic reactions. The positive effects of phosphine ligands in transition metal homogeneous catalysis have contributed largely to the evolution of the field into an indispensable tool in organic synthesis and the industrial production of chemicals.
This book aims to address the design and synthesis of a comprehensive compilation of P(III) ligands for homogeneous catalysis. It not only focuses on the well-known traditional ligands that have been explored by catalysis researchers, but also includes promising ligand types that have traditionally been ignored mainly because of their challenging synthesis.
Topics covered include ligand effects in homogeneous catalysis and rational catalyst design, P-stereogenic ligands, calixarenes, supramolecular approaches, solid phase synthesis, biological approaches, and solubility and separation.
Ligand families covered in this book include phosphine, diphosphine, phosphite, diphosphite, phosphoramidite, phosphonite, phosphinite, phosphole, phosphinine, phosphinidenene, phosphaalkenes, phosphaalkynes, P-chiral ligands, and cage ligands.
Each ligand class is accompanied by detailed and reliable synthetic procedures. Often the rate limiting step in the application of ligands in catalysis is the synthesis of the ligands themselves, which can often be very challenging and time consuming. This book will provide helpful advice as to the accessibility of ligands as well as their synthesis, thereby allowing researchers to make a more informed choice.
Phosphorus(III) Ligands in Homogeneous Catalysis: Design and Synthesis is an essential overview of this important class of catalysts for academic and industrial researchers working in catalyst development, organometallic and synthetic chemistry.Hinweis: Dieser Artikel kann nur an eine deutsche Lieferadresse ausgeliefert werden.
Paul C.J. Kamer, EaStCHEM, School of Chemistry, University of St. Andrews, Scotland. Piet W.N.M. van Leeuwen, Institute of Chemical Research of Catalonia (ICIQ), Tarragona, Spain.
Inhaltsangabe
List of Contributors xv Preface xix 1 Phosphorus Ligand Effects in Homogeneous Catalysis and Rational Catalyst Design 1 Jason A. Gillespie, Erik Zuidema, Piet W. N. M. van Leeuwen, and Paul C. J. Kamer 1.1 Introduction 1 1.2 Properties of phosphorus ligands 7 1.2.1 Electronic ligand parameters 7 1.2.2 Steric ligand parameters 9 1.2.3 Bite angle effects 10 1.2.3.1 Electronic bite angle effect 11 1.2.3.2 Steric bite angle effect 12 1.2.3.3 Steric versus electronic bite angle effects 12 1.2.4 Molecular electrostatic potential (MESP) approach 13 1.3 Asymmetric ligands 15 1.4 Rational ligand design in nickel-catalysed hydrocyanation 19 1.4.1 Introduction 19 1.4.2 Mechanistic insights 20 1.4.3 Rational design 20 1.5 Conclusions 22 References 23 2 Chiral Phosphines and Diphosphines 27 Wei Li and Xumu Zhang 2.1 Introduction 27 2.1.1 Early developments 27 2.2 Chiral chelating diphosphines with a linking scaffold 30 2.2.1 Building chiral backbones from naturally available materials 30 2.2.1.1 Early development 30 2.2.1.2 Syntheses of DIOP variants 31 2.2.1.3 Synthesis from other natural chiral backbones 33 2.2.2 Design and synthesis of chiral backbones 35 2.2.2.1 Chiral backbones synthesized through asymmetric catalysis 35 2.2.2.2 Design and synthesis of ligands containing spiro backbones 37 2.2.2.3 Design and synthesis of chiral ferrocene backbones 40 2.2.2.4 Design and synthesis of other chiral backbones 41 2.2.3 Synthesis from optical resolution of phosphine precursors or intermediates 43 2.3 Chiral atropisomeric biaryl diphosphines 46 2.3.1 Synthesis of BINAP and its derivatives 46 2.3.2 Synthesis of atropisomeric biaryl ligands 49 2.3.3 General strategies of synthesizing of atropisomeric biaryl ligands 52 2.4 Chiral phosphacyclic diphosphines 52 2.4.1 Fundamental discovery and syntheses of BPE and DuPhos 52 2.4.2 Design and synthesis of bisphosphetanes 56 2.4.3 Design and synthesis of bisphospholanes 58 2.4.3.1 BPE and DuPhos analogue ligands 58 2.4.3.2 P-stereogenic bisphospholane ligands 60 2.4.4 Design and synthesis of bisphospholes 63 2.4.5 Design and synthesis of bisphosphinanes 65 2.4.6 Design and synthesis of bisphosphepines 66 2.4.7 Summary of synthetic strategies of phosphacycles 68 2.5 P-stereogenic diphosphine ligands 68 2.6 Experimental procedures for the syntheses of selected diphosphine ligands 69 2.6.1 Synthesis procedure for DIOP* ligand 69 2.6.2 Synthesis procedure of SDP ligands 70 2.6.3 Synthesis procedure of ( R , R )-BICP 71 2.6.4 Synthesis procedure of SEGPHOS 71 2.6.5 Synthesis procedure of Ph-BPE 72 2.6.6 Synthesis procedure of TangPhos 73 2.6.7 Synthesis procedure of Binaphane 74 2.7 Concluding remarks 75 References 75 3 Design and Synthesis of Phosphite Ligands for Homogeneous Catalysis 81 Aitor Gual, Cyril Goddard, Verónica de la Fuente, and Sergio Castillón 3.1 Introduction 81 3.2 Synthesis of phosphites 82 3.2.1 Monophosphites 82 3.2.1.1 Symmetrically substituted monophosphites 82 3.2.1.2 Nonsymmetrically substituted monophosphites 83 3.2.1.3 Caged monophosphites 84 3.2.1.4 Monophosphites bearing dioxaphospho-cyclic units 84 3.2.2 Diphosphite ligands 94 3.2.2.1 Diphosphites not containing a dioxaphospho-cyclic unit 94 3.2.2.2 Diphosphites bearing dioxaphospho-cyclic units 95 3.2.3 Triphosphites 105 3.3 Highlights of catalytic applications of phosphite ligands 106 3.3.1 Hydrogenation reactions 106 3.3.2 Functionalization of alkenes: hydroformylation and hydrocyanation 108 3.3.2.1 Hydroformylation 108 3.3.2.2 Hydrocyanation 110 3.3.3 Addition of nucleophiles to carbonyl compounds and derivatives 110 3.3.3.1 1,2-addition 111 3.3.3.2 1,4-addition 111 3.3.4 Allylic substitution reactions 113 3.3.5 Miscellaneous reactions 117 3.4 General synthetic procedures 122 3.4.1 Symmetrically substituted phosphites 122 3.4.2 Nonsymmetrically substituted phosphites 123 3.4.3 Phosphites bearing dioxaphospho-cyclic units 123 References 124 4 Phosphoramidite Ligands 133 Laurent Lefort and Johannes G. de Vries 4.1 Introduction 133 4.1.1 History 134 4.2 Synthesis of phosphoramidites 134 4.3 Reactivity of the phosphoramidites 135 4.4 Types of phosphoramidite ligands 136 4.4.1 Acyclic monodentate phosphoramidites 136 4.4.2 Cyclic monodentate phosphoramidites based on diols 136 4.4.2.1 Synthesis of binaphthol- and biphenol-based phosphoramidites 137 4.4.2.2 Synthesis of TADDOL-based phosphoramidites 140 4.4.2.3 Synthesis of spiro-based phosphoramidites 141 4.4.2.4 Synthesis of 1,2-diol-based phosphoramidites 141 4.4.2.5 Phosphoramidites based on unusual diols 141 4.4.3 Cyclic phosphoramidites based on amino alcohols 142 4.4.4 Bis-phosphoramidites 143 4.4.4.1 Bis-phosphoramidites based on diamines 143 4.4.4.2 Bis-phosphoramidites based on diols 144 4.4.4.3 Other bidentate phosphoramidites 145 4.4.5 Mixed bidentate ligands 145 4.4.5.1 Phosphoramidite-phosphines 145 4.4.5.2 Phosphoramidite-phosphite 147 4.4.5.3 Phosphoramidite-amines 148 4.4.5.4 Other bidentate phosphoramidite ligands 149 4.4.6 Polydendate phosphoramidites 149 4.5 Conclusion 153 4.6 Synthetic procedures 153 References 153 5 Phosphinite and Phosphonite Ligands 159 T. V. (Babu) RajanBabu 5.1 Introduction 159 5.2 General methods for synthesis of complexes 160 5.3 Syntheses and applications of phosphinite ligands 162 5.3.1 Early studies 162 5.3.2 Phosphinite ligands from carbohydrates 163 5.3.2.1 Rh-catalyzed asymmetric hydrogenation of dehydroaminoacids 164 5.3.2.2 Ni(0)-catalyzed asymmetric hydrocyanation 166 5.3.2.3 Ni(0)- and Pd(0)-catalyzed allylic substitution by carbon nucleophiles 170 5.3.2.4 Rh(I)-catalyzed hydroformylation of vinylarenes 171 5.3.2.5 Ni(II)-catalyzed asymmetric hydrovinylation of alkenes 171 5.3.2.6 Ligands for homogeneous catalysis in water 172 5.3.3 Phosphinite ligands from other alcohols 172 5.3.4 Phosphine-phosphinite and amine-phosphinite ligands 173 5.3.5 Phosphinites from amines, amino alcohols, and amino acids 174 5.3.5.1 Aminophosphines 174 5.3.5.2 Aminophosphine-phosphinite (AMPP) ligands 176 5.3.6 Bisphosphinite ligands with other scaffoldings 179 5.3.7 1,1'-Diaryl-2,2'-phosphinites and dynamic conformational control in asymmetric catalysis 180 5.3.8 Monophosphinite ligands 182 5.3.9 Hybrid ligands containing phosphinites 182 5.3.9.1 Thioether-phosphinite ligands 182 5.3.9.2 Oxazoline-phosphinite and pyridine-phosphinite ligands 184 5.3.9.3 An alkene-phosphinite ligand 186 5.3.9.4 Chiral transition metal Lewis acids bearing electron-withdrawing phosphinites 187 5.4 Synthesis and applications of phosphonite ligands 188 5.4.1 Early studies 188 5.4.2 Phosphonites from TADDOL and related compounds 189 5.4.3 Phosphonites derived from 2,2'-hydroxybiaryls and related compounds 193 5.4.4 Phosphine-phosphonite ligands 196 5.4.5 Phosphonites with paracyclophane backbone 196 5.4.6 Phosphonites with a spirobisindane backbone 197 5.4.7 Miscellaneous phosphonite ligands 198 5.4.8 Development of phosphonite ligands for industrially relevant processes 199 5.4.8.1 Phosphonite ligands in hydroformylation 199 5.4.8.2 Phosphonite ligands in Ni(0)-catalyzed hydrocyanation 201 5.4.8.3 Oxazoline-phosphonite ligands and olefin dimerization 203 5.4.9 Use of the phosphonite functionality to synthesize other ligands 206 5.5 Experimental procedures for the syntheses of prototypical phosphinite and phosphonite ligands 208 5.5.1 Phosphinite ligands 208 5.5.1.1 Me 2 P(OMe) 208 5.5.1.2 Et 2 POEt and EtP(OEt) 2 209 5.5.1.3 Synthesis of methyl 3,4-bis- O -[bis(3,5-dimethylphenyl)phosphino]- 2,6-di- O -benzoyl- a - D -glucopyranoside (Ligand 8) 209 5.5.1.4 Preparation of phenyl 2,3-bis- O -[bis[3,5-bis(trifluoromethyl) phenyl]-phosphino)-4,6- O -benzylidene-glucopyranoside 211 5.5.1.5 Preparation of bis-(pentafluorophenyl)chlorophosphine 212 5.5.1.6 An alternate general procedure for phosphinite incorporation. [(2S,3R)-3-phenylthio-4-methylpent-2-oxy]diphenylphosphine 212 5.5.1.7 Metal-template synthesis of an amino1,2-diarylphosphinediarylphophinite complex 213 5 5.5.1.8 Procedure for the preparation of a bis-aminodiaryphosphine (R)-37 213 5.5.1.9 (-)-(S)-4- tert -butyl-2-{1-di(2'-methylphenyl)phosphinite- 1-methyl-ethyl}-4,5-dihydro-oxazole 214 5.5.1.10 (R)-7-(2-phenyl-6,7-dihydro-5H-[1]pyrindin)-di-(2'-methylphenyl)- phosphinite 215 5.5.2 Phosphonite ligands 217 5.5.2.1 (IR,7R)-9,9-dimethyl-2,2,4,6.6-penta(2-naphthyl)-3,5,8,l0-tetraoxa- 4-phosphabicyclo[5.3.0]-decane 217 5.5.2.2 (IR,7R)-9,9-dimethyl-2,2,4,6.6-penta(2-naphthyl)-3,5,8,l0-tetraoxa- 4-phosphabicyclo/5.3.0]-decane 218 5.5.2.3 Synthesis of (S)-2-[2-(diphenylphosphino)phenyl]-1,3,2-dinaphtho [d1,2,f1,2]dioxaphosphe-pine 219 5.5.2.4 4,5-Bis{di[(2-tert-butyl)phenyl]phosphonito}-9,9-dimethylxanthene 219 5.6 Acknowledgments 221 Abbreviations 221 References 222 6 Mixed Donor Ligands 233 René Tannert and Andreas Pfaltz 6.1 Introduction: general design principles 233 6.2 Synthesis of bidentate P,X-ligands 235 6.2.1 P,N-ligands 235 6.2.1.1 Oxazoline-based P,N-ligands 235 6.2.1.2 Imidazoline-based P,N-ligands 243 6.2.1.3 Oxazole-, thiazole-, and imidazole-based P,N-ligands 243 6.2.1.4 Pyridine-based P,N-ligands 245 6.2.1.5 Amine- and imine-based P,N-ligands 247 6.2.1.6 Other P,N-ligands 250 6.2.2 P,O-ligands 250 6.2.3 P,S-ligands 252 6.2.4 P,C-ligands 255 6.3 Conclusion 257 6.4 Experimental procedures 257 6.4.1 Synthesis of PHOX ligand 257 6.4.2 Synthesis of NeoPHOX ligand 259 References 260 7 Phospholes 267 Duncan Carmichael 7.1 Introduction 267 7.2 Creation of phospholes for use as ligands 269 7.2.1 Reactions of phosphorus dihalides with metallated dienes 269 7.2.2 Reactions of phosphorus dihalides with dienes 270 7.2.3 Michael addition of primary phosphines to dienes 271 7.3 Postsynthetic functionalisation 271 7.3.1 Functionalisation at phosphorus 271 7.3.2 Use of electrophiles 272 7.3.3 Use of nucleophiles and aromatics 272 7.3.4 Elaboration about the phosphole nucleus 272 7.4 Phosphole coordination chemistry 273 7.5 Phospholes in catalysis 276 7.6 Experimental procedures 279 References 280 8 Phosphinine Ligands 287 Christian Müller 8.1 Introduction 287 8.2 Ligand properties 288 8.2.1 Electronic properties 288 8.2.2 Structural characteristics and steric properties 289 8.2.3 Reactivity of phosphinines 290 8.3 Synthesis of Phosphinines 292 8.3.1 O + /P exchange reaction 292 8.3.2 Tin route 294 8.3.3 [4 + 2] cycloaddition reactions 294 8.3.4 Ring expansion methods 295 8.3.5 Metal-mediated functionalizations 296 8.4 Coordination chemistry 297 8.5 Reactivity of transition metal complexes 300 8.6 Application of phosphinines in homogeneous catalysis 300 8.7 Experimental procedure for the synthesis of selected phosphinines 303 References 305 9 Highly Strained Organophosphorus Compounds 309 J. Chris Slootweg 9.1 Introduction 309 9.2 Three-membered rings 310 9.3 Rearrangements 312 9.4 Homogeneous catalysis 313 9.5 Conclusions 314 9.6 Experimental procedures 315 9.6.1 Synthesis of BABAR-Phos 49a (R = i-Pr) 315 9.6.2 Synthesis of BABAR-Phos 49b (R = 3,5-(CF3)2C6H3) 316 References 317 10 Phosphaalkenes 321 Julien Dugal-Tessier, Eamonn D. Conrad, Gregory R. Dake, and Derek P. Gates 10.1 Introduction 321 10.1.1 Frontier molecular orbitals of phosphaalkenes 322 10.2 Synthesis of phosphaalkenes 324 10.2.1 Diphosphinidenecyclobutene (DPCB) synthesis (P,P chelates) 324 10.2.2 Bidentate-chelating P,P phosphaalkene ligands 325 10.2.3 Phosphaalkenes capable of P,N-chelation to metals 326 10.2.4 P,X achiral phosphaalkene ligands (X=P, O, S) 326 10.2.5 Synthesis of enantiomerically pure P,X ligands (X=P, N) 328 10.3 Catalysis with phosphaalkene ligands 329 10.3.1 Ethylene polymerization 329 10.3.2 Cross-coupling reactions 330 10.3.3 Hydro- and dehydrosilylation 332 10.3.4 Hydroamination and hydroamidation 333 10.3.5 Isomerization reactions 334 10.3.6 Allylic substitution 335 10.3.7 Asymmetric catalysis 336 10.4 Concluding remarks 337 10.5 Experimental procedures for representative ligands 338 10.5.1 Synthesis of DPCB 338 10.5.2 Synthesis of PhAk-Ox 338 10.6 Acknowledgments 339 References 339 11 Phosphaalkynes 343 Christopher A. Russell and Nell S. Townsend 11.1 Introduction 343 11.2 General experimental 344 11.3 Preparation of PC t Bu 344 11.3.1 Tris(trimethylsilyl)phosphine, P(SiMe 3 ) 3 345 11.3.2 tert -butylphosphaalkene, Me 3 SiP = C(OSiMe 3 ) t Bu (systematic name [2,2-dimethyl-1-(trimethylsiloxy)propylidene]-(trimethylsilyl) phosphine) 346 11.3.3 (2,2-dimethylpropylidyne)phosphine; t BuC=P 347 11.4 Adamanylphosphaalkyne, AdC=P 348 11.4.1 Adamant-1-yl(trimethylsiloxy)methylidene (trimethylsilyl) phosphane 348 11.4.2 (Adamant-1-ylmethylidyne)phosphane 348 11.5 Mesitylphosphaalkyne, MesC=P 349 11.5.1 Preparation of potassium bis(trimethylsilyl)phosphide {KP(SiMe 3 ) 2 } 349 11.5.2 Mesityl(trimethylsiloxy)methylene trimethylsilylphosphane 349 11.5.3 Mesitylphosphaalkyne 350 11.6 Phospholide anions 350 11.6.1 Preparation of Cp 2 Zr(PC t Bu) 2 351 11.6.2 Preparation of ClP(PC t Bu) 2 351 11.6.3 Preparation of the triphospholide anion and derivation to give the triphenylstannylphosphole 352 11.6.4 Preparation of Cl 3 P 3 (C t Bu) 2 352 11.6.5 Preparation of the triphospholide anion 352 11.7 1,3,5-Triphosphabenzene 352 11.7.1 Preparation of Cl 3 VN t Bu 353 11.7.2 Preparation of 1,3,5-triphospabenzene; P 3 (C t Bu) 3 353 References 353 12 P-chiral Ligands 355 Jérôme Bayardon and Sylvain Jugé 12.1 Introduction 355 12.2 Designing P-chiral ligands using alcohols as chiral auxiliaries 357 12.3 Designing P-chiral ligands using amino alcohols as chiral auxiliaries 363 12.3.1 Synthesis starting from tricoordinated 1,3,2-oxazaphospholidines 363 12.3.2 Synthesis starting from tetracoordinated 1,3,2-oxazaphospholidines 364 12.3.3 Synthesis starting from 1,3,2-oxazaphospholidine borane complexes 366 12.3.3.1 Interest of the borane-phosphorus complex chemistry 366 12.3.3.2 Ephedrine method 366 12.3.3.3 Methyl phosphinite boranes as P-chiral electrophilic building blocks 367 12.3.3.4 Chlorophosphine boranes as P-chiral electrophilic building blocks 368 12.3.3.5 Designing P-chiral aminophosphine phosphinites (AMPP*) 371 12.3.3.6 P-chiral o -hydroxyaryl phosphines 371 12.3.3.7 P-chiral secondary phosphine boranes 373 12.3.3.8 P-chiral 1,2-diphosphinobenzenes 373 12.3.3.9 Strategies for the enantiodivergent synthesis of P-chiral ligands 375 12.4 Designing of P-chiral ligands using amines as chiral auxiliaries 377 12.4.1 Sparteine as chiral auxiliary 377 12.4.2 a -Arylethylamines as chiral auxiliaries 381 12.5 Conclusion 381 12.6 Experimental procedures 383 References 385 13 Phosphatrioxa-Adamantane Ligands 391 Paul G. Pringle and Martin B. Smith 13.1 Introduction 391 13.2 Synthesis of phosphatrioxa-adamantanes 393 13.3 Catalysis supported by phosphatrioxa-adamantane ligands 395 13.3.1 Alkoxycarbonylation 395 13.3.2 Hydroformylation and hydrocyanation 397 13.3.3 Pd-catalysed coupling reactions 399 13.3.4 Asymmetric hydrogenation 400 13.4 Experimental procedures for phosphatrioxa-adamantanes ligands 401 13.4.1 Preparation of CgPH 401 13.4.2 Preparation of CgPH(BH 3 ) 402 13.4.3 Preparation of CgPBr 402 13.4.4 Preparation of CgPCH 2 CH 2 CH 2 PCg (L1) 402 13.4.5 Preparation of CgPPh (L7) 402 References 402 14 Calixarene-based Phosphorus Ligands 405 Angelica Marson, Piet W. N. M. van Leeuwen, and Paul C. J. Kamer 14.1 Introduction 405 14.2 Conformational properties 407 14.3 Calixarene-based phosphorus ligands 409 14.3.1 Phosphines and phosphinites 409 14.3.2 Phosphites and phosphonites 414 14.4 Applications in homogeneous catalysis 422 14.5 Experimental procedures 424 References 425 15 Supramolecular Bidentate Phosphorus Ligands 427 Jarl Ivar van der Vlugt and Joost N. H. Reek 15.1 Introduction: general design principles 427 15.2 Construction of bidentate phosphorus ligands via self-assembly 429 15.2.1 H bonding 429 15.2.2 Metal template assembly 440 15.2.3 Ion templation 445 15.3 Conclusions 446 15.4 Experimental procedures 447 15.4.1 General remarks 447 15.4.2 Synthesis of UREAPhos 447 15.4.3 Synthesis of METAMORPhos 448 15.4.4 Synthesis of supraphos 450 References 459 16 Solid-phase Synthesis of Ligands 463 Michiel C. Samuels, Bert H. G. Swennenhuis, and Paul C. J. Kamer 16.1 Introduction 463 16.2 Insoluble supports in ligand synthesis 466 16.3 Soluble polymeric supports 470 16.4 Supported ligands in catalysis 472 16.5 Solid-phase synthesis of nonsupported ligands 473 16.6 Conclusions and outlook 475 16.7 Experimental procedures 476 References 478 17 Biological Approaches 481 René den Heeten, Paul C. J. Kamer, and Wouter Laan 17.1 Introduction 481 17.2 Peptide-based phosphine ligands 481 17.2.1 Solid-phase synthesis using phosphine-containing amino acids 481 17.2.1.1 Synthesis of phosphine-containing amino acids 482 17.2.1.2 Synthesis and application of phosphine-containing peptides 484 17.2.2 Functionalisation of peptides with phosphines 485 17.2.2.1 Phosphinomethylation of amines 485 17.2.2.2 Phosphine modification of peptides via imine or amide formation 485 17.3 Oligonucleotide-based phosphine ligands 487 17.3.1 Covalent anchoring of phosphines to DNA 487 17.4 Phosphine-based artificial metalloenzymes 488 17.4.1 Supramolecular anchoring of phosphines to proteins 489 17.4.1.1 Avidin-biotin 489 17.4.1.2 Antibodies 490 17.4.2 Covalent anchoring of phosphines 491 17.5 Conclusions and outlook 492 17.6 Representative synthetic procedures 493 17.6.1 Artificial hydrogenases based on the biotin-streptavidin technology 493 17.6.2 Site-selective covalent modification of proteins with phosphines via hydrazone linkage 494 17.7 Acknowledgments 495 References 495 18 The Design of Ligand Systems for Immobilisation in Novel Reaction Media 497 Paul B. Webb and David J. Cole Hamilton 18.1 Introduction 497 18.2 Aqueous biphasic catalysis 499 18.3 Fluorous biphasic catalysis 503 18.4 Ionic liquids as reaction media 507 18.5 Supercritical fluids as solvents in single- and multiphasic reaction systems 512 18.5.1 Biphasic systems based on CO2 516 18.6 Experimental section 518 18.6.1 Trisodium salt of 3,3 ,3 -phosphinetriylbenzenesulfonic acid (TPPTS) 518 18.6.2 2,7-bis(SO3Na)-Xantphos 519 18.6.3 Sulfonated BINAP 519 18.6.4 Synthesis of Tris(1H,1H,2H,2H-perfluorooctyl)phosphine 520 18.6.5 Synthesis of Tris (4-tridecafluorohexylphenyl)phosphine 520 18.6.6 (Meta-sulfonatophenyl)diphenylphosphine, sodium salt (monosulfonated triphenylphosphine, TPPMS) 522 18.6.7 1-Propyl-3-methylimidazolium diphenyl(3-sulfonatophenyl)-phosphine ([PrMIM][TPPMS]) 523 18.6.8 4,4 -Phosphorylated 2,2 -Bis(diphenylphosphanyl)-1,1 -binaphthyl 523 18.6.9 Synthesis of (R)-6,6 -bis(perfluorohexyl)-2,2 bis (diphenylphosphino)-1,1 -binaphthyl ((R)-Rf-BINAP) 524 References 526 Index