Handbook of Green Chemistry, Volume 4: Supercritical Solvents

Handbook of Green Chemistry, Volume 4: Supercritical Solvents......Page 1
Contents......Page 2
1.1 What is a Supercritical Fluid (SCF)?......Page 3
1.2 Practical Aspects of Reactions in Supercritical Fluids......Page 6
1.3 The Motivation for Use of SCFs in Modern Chemical Synthesis......Page 8
The Discovery of SCFs and Their Use as Solvents......Page 11
Extraction and Chromatography in SCFs......Page 16
The History of Chemical Reactions in SCFs......Page 18
Industrial Use of SCFs as Reaction Media......Page 22
References......Page 26
2.1 Introduction......Page 33
Location......Page 34
Gas Supply, Compression, and Purification......Page 35
Metal Components......Page 36
Sealing Materials......Page 37
Pressure Vessels for Batch Processing......Page 43
Continuous Flow Reactors......Page 46
Tubes and Fittings......Page 47
Pressure Transmitter and Manometer......Page 49
Reactor Heating and Temperature Control......Page 50
Stirrer Types......Page 53
Pressure Safety Valves and Bursting Discs......Page 55
Online Sampling......Page 56
Inline Spectroscopic Measurements......Page 58
Cleaning with Organic Solvents......Page 59
Safety Warnings Pressure Rise Due to Temperature Increase......Page 60
Dosing in Batch Processes Gravimetric Dosage......Page 62
Dosage for Continuous Flow Processes......Page 63
Dosage of Liquids......Page 64
Supply Pressure......Page 66
Reactor Pressure......Page 67
Condensation......Page 68
Brief Description of Work Steps......Page 69
Work-up......Page 70
Fully Automated System for Continuous Flow Operation......Page 71
References......Page 75
3.2 Basic Physical Properties of Supercritical Fluids......Page 79
Types of Binary Phase Diagrams......Page 88
Asymmetric Binary Mixtures......Page 90
The Supercritical Solvent......Page 94
Chemical Functionality of the Solute......Page 96
Temperature and Pressure Effects......Page 98
References......Page 99
4.1 A Practical Classification of Biphasic Systems Consisting of Liquids and Compressed Gases for Multiphase Catalysis......Page 103
Volumetric Expansion......Page 108
Density......Page 111
Viscosity......Page 112
Melting Point......Page 113
Interfacial Tension......Page 114
Diffusivity......Page 116
Polarity......Page 117
Gas Solubility......Page 120
In Situ Generation of Acids and Temporary Protection Strategies......Page 122
Switchable Solvents and Catalyst Systems......Page 126
Motivation and Potential Benefits......Page 131
Tunable Precipitation and Crystallization......Page 132
Tunable Phase Separations......Page 133
Tunable Miscibility......Page 136
Hydrogenation Reactions......Page 137
Carbonylation Reactions......Page 141
Oxidation Reactions......Page 145
Miscellaneous......Page 150
4.5 Why Perform Liquid–SCF Biphasic Reactions?......Page 152
By Necessity (Unintentional Immiscibility)......Page 153
To Facilitate Post-Reaction Separation......Page 154
To Facilitate Product/Catalyst Separation in Continuous Flow Systems......Page 156
To Stabilize a Catalyst......Page 157
To Control the Concentration of Reagent or Product in the Reacting Phase......Page 158
To Permit Emulsion Polymerization......Page 159
To Create Templated Materials......Page 160
Aqueous–SCF Biphasic Systems......Page 161
Ionic Liquid–SCF Biphasic Systems......Page 165
Polymer–SCF Biphasic Systems......Page 169
Liquid Product–SCF Biphasic Systems......Page 173
Water-in-SCF Inverse Emulsions......Page 174
Ionic Liquid-in-SCF Emulsions......Page 175
Applications of Emulsions......Page 176
References......Page 177
5.1 Introduction......Page 191
5.2 Hydrogenation in Supercritical Fluids......Page 192
Asymmetric Hydrogenation and Related Reactions......Page 200
5.3 Hydroformylation and Related Reactions in Supercritical Fluids......Page 204
5.4 Oxidation Reactions in Supercritical Fluids......Page 207
5.5 Palladium-mediated Coupling Reactions in Supercritical Fluids......Page 210
Metal-catalyzed Processes......Page 216
Base-catalyzed Processes......Page 220
Acid-Catalyzed Processes......Page 221
5.7 Cycloaddition Reactions in Supercritical Fluids......Page 223
5.8 Photochemical Reactions in Supercritical Fluids......Page 226
5.9 Radical Reactions in Supercritical Fluids......Page 230
5.10 Biotransformations in Supercritical Fluids......Page 231
Acknowledgments......Page 236
References......Page 237
6.1 Introduction and Scope......Page 245
6.2 General Aspects of Heterogeneous Catalysis in SCFs and GXLs......Page 246
General Considerations......Page 247
Rate Enhancement......Page 249
Selectivity Tuning......Page 250
Lifetime/Stability Enhancement......Page 252
Utilization of GXLs in Heterogeneous Catalysis......Page 253
Conversions in SCFs......Page 254
Hydrogenations......Page 258
Fischer–Tropsch Synthesis......Page 262
Hydroformylations......Page 264
Oxidations......Page 265
Alkylations......Page 268
Isomerizations......Page 271
Miscellaneous......Page 272
Conversions in GXLs......Page 273
6.4 Outlook......Page 275
References......Page 276
7.1 Enzymes in Non-aqueous Environments......Page 283
7.2 Supercritical Fluids for Enzyme Catalysis......Page 285
7.3 Enzymatic Reactions in Supercritical Fluids......Page 287
7.4 Reaction Parameters in Supercritical Biocatalysis......Page 291
7.5 Stabilized Enzymes for Supercritical Biocatalysis......Page 294
7.6 Enzymatic Catalysis in IL–scCO2 Biphasic Systems......Page 296
References......Page 300
Introduction and Scope......Page 305
Supercritical Fluids......Page 306
Solubility of Macromolecules in scCO......Page 308
Stabilizer Design for Dispersion Polymerizations......Page 312
Limitations of Polymer Preparation in scCO......Page 316
Radical Polymerization in scCO2......Page 317
Side-chain Fluoropolymers......Page 319
Fluoroolefin Polymers......Page 321
Poly(Methyl Methacrylate)......Page 328
Polystyrene......Page 334
Other Vinyl Monomers......Page 337
Polyolefins......Page 342
Other Metal-catalyzed Polymerizations......Page 344
Cationic Polymerizations......Page 348
Coordinative Anionic Polymerization......Page 350
8.3 Conclusion......Page 354
References......Page 355
Direct Synthesis of Nanocrystals in SCFs......Page 371
Synthesis in scCO2......Page 372
Synthesis in Supercritical Organic Solvents......Page 373
Synthesis in Supercritical Water (scH2O)......Page 375
Water-in-Supercritical Alkane Microemulsion......Page 376
Water-in-scCO2 Microemulsions......Page 377
Supercritical Hydrothermal Synthesis......Page 379
Direct Sol–Gel Synthesis in scCO2......Page 382
Synthesis Using Water-in-CO2 Microemulsions......Page 384
Carbon Nanotubes (CNTs)......Page 385
9.5 Nanocomposites......Page 387
Synthesis of Polymer-based Composites......Page 388
Decoration of Nanoparticles on Carbon Nanotubes......Page 390
Deposition of Nanoparticles on Porous Supports......Page 393
9.6 Conclusion......Page 395
References......Page 396
"Solvent" Properties of Supercritical Fluids......Page 401
Experimental Considerations......Page 402
Photodimerization......Page 405
Carbonyl Photochemistry......Page 407
Photosensitization and Photo-induced Electron Transfer......Page 411
Free Radical Brominations of Alkyl Aromatics in Supercritical Carbon Dioxide......Page 412
Free Radical Chlorination of Alkanes in Supercritical Fluid Solvents......Page 413
10.4 Conclusion......Page 416
References......Page 417
11.2 Electrochemical Methods......Page 421
11.3 Analytes......Page 422
11.5 Electrochemical Cell and Supercritical Fluid Delivery System......Page 423
Reference Electrode......Page 424
11.7 Solvents......Page 425
Supercritical Carbon Dioxide......Page 426
Electrode Modification......Page 427
Hydrofluorocarbon Supercritical Solvents......Page 428
Electrochemical Detection in Supercritical Solvents......Page 431
References......Page 433
Background......Page 437
Phase Transfer Catalysis Quaternary Ammonium Salt-catalyzed Reactions......Page 438
PTC Separation and Recycling Using CO2......Page 439
Definition......Page 440
Properties......Page 441
Friedel–Crafts Chemistry in NCW......Page 444
Probing Alkylcarbonic Acids – Alkylcarbonic Acids with Diazodiphenylmethane (DDM)......Page 450
Ketal Formation......Page 453
Formation of Diazonium Salts......Page 454
12.5 Conclusion......Page 455
References......Page 456
13.2 Properties......Page 459
13.3 Synthesis Reactions [1, 3–5]......Page 461
Esters......Page 462
Dehydrations......Page 463
Diels–Alder Reactions......Page 464
Rearrangements......Page 465
Reductions......Page 466
Carbohydrates......Page 467
Proteins......Page 469
Oil, Gases, Coke......Page 470
13.5 Supercritical Water Oxidation (SCWO)......Page 472
Corrosion......Page 473
13.7 Conclusion......Page 474
References......Page 475