11.Microwaves in Cycloadditions ............................... 524
Khalid Bougrin, Mohamed Soufiaoui, and George
Bashiardes
11.1.Cycloaddition Reactions .................................. 524
11.2.Reactions with Solvent ................................... 525
11.3.Reactions under Solvent-free Conditions .................. 526
11.3.1.Reaction on Mineral Supports ...................... 527
11.3.2.Reaction with Neat Reactants ...................... 528
11.4.[4+2] Cycloadditions ..................................... 532
11.4.1.Intramolecular Hetero and Diels-Alder Reactions ... 533
11.4.2.Intermolecular Hetero and Diels-Alder Reactions ... 538
11.5.[3+2] Cycloadditions ..................................... 546
11.5.1.Nitrile Oxides, Nitrile Sulfides, and Nitrones .... 547
11.5.2.Azomethine Ylides, and Nitrile I mines ............ 556
11.5.3.Azides ............................................ 562
11.6.[2+2] Cycloadditions ..................................... 567
11.6.1.Cycloadditions of Ketenes with Imines ............. 567
11.6.2.Cycloadditions of β-Formyl Enamides with
Alkynes ........................................... 569
11.7.Other Cycloadditions ..................................... 570
11.8.Conclusions .............................................. 571
Acknowledgments ............................................... 572
References .................................................... 573
12.Microwave-assisted Chemistry of Carbohydrates .............. 579
Antonino Corsaro, Ugo Chiacchio, Venerando Pistara,
and Giovanni Romeo
12.1.Introduction ............................................. 579
12.2.Protection ............................................... 580
12.2.1.Acylation ......................................... 580
12.2.2.Acetalation ....................................... 583
12.2.3.Silylation ........................................ 585
12.2.4.Methylation of Carbohydrate Carboxylic Acids ...... 586
12.2.5.Synthesis of l,6-Anhydro-/?-D-hexopyranoses ....... 586
12.3.Deprotection ............................................. 586
12.3.1.Deacylation ....................................... 587
12.3.2.Deacetalation ..................................... 588
12.3.3.Desilylation ...................................... 588
12.4.Glycosylation ............................................ 589
12.4.1.O-Glycosylation ................................... 589
12.4.2.C-Glycosylation Reactions ......................... 594
12.4.3.N-Glycosylation ................................... 594
12.5.Hydrogenation (Catalytic Transfer Hydrogenation) ......... 594
12.6.Oxidation ................................................ 595
12.7.Halogenation ............................................. 595
12.7.1.Chlorination and Bromination ...................... 595
12.7.2.Fluorination ...................................... 596
12.7.3.Iodination ........................................ 597
12.8.Stereospecific С—Н Bond Activation for Rapid Deuterium
Labeling ................................................. 597
12.9.Reaction of Carbohydrates with Amino-derivatized
Labels ................................................... 598
12.10.Ferrier (II) Rearrangement to Carbasugars ............... 599
12.11.Synthesis of Unsaturated Monosaccharides ................ 599
12.12.Synthesis of Dimers and Polysaccharides, and their
Derivatives ............................................. 601
12.13.Synthesis of Heterocycles and Amino Acids ............... 602
12.13.1.Spiroisoxazoli(di)ne Derivatives ................. 602
12.13.2.Triazole-linked Glycodendrimers .................. 603
12.13.3.5,6-Dihydro-l,2,3,4-tetrazenes ................... 604
12.13.4.C-Nucleosides .................................... 605
12.13.5.Pterins .......................................... 605
12.13.6.Epoxides ......................................... 606
12.13.7.Azetidinones ..................................... 607
12.13.8.Substituted Pyrazoles ............................ 608
12.13.9.3H-Pyrido[3,4-b]indole Derivatives ............... 608
12.14.Enzymatic Reactions ..................................... 608
12.15.Conclusion .............................................. 611
References .................................................... 611
13.Microwave Catalysis in Organic Synthesis ................... 615
Milan Hajek
13.1.Introduction ............................................. 615
13.1.1.Definitions ....................................... 616
13.2.Preparation of Heterogeneous Catalysts ................... 617
13.2.1.Drying and Calcination ............................ 617
13.2.2.Catalyst Activation and Reactivation
(Regeneration) .................................... 620
13.3.Microwave Activation of Catalytic Reactions .............. 621
13.3.1.Reactions in the Liquid Phase ..................... 622
13.3.2.Reactions in the Gas Phase ........................ 628
13.3.3.Microwave Effects ................................. 634
13.3.4.Microwave Catalytic Reactors ...................... 641
13.4.Industrial Applications .................................. 645
References ............................................... 647
14.Polymer Chemistry Under the Action of Microwave
Irradiation ................................................ 653
Dariusz Bogdal and Katarzyna Matras
14.1.Introduction ............................................. 653
14.2.Synthesis of Polymers Under the Action of Microwave
Irradiation .............................................. 653
14.2.1.Chain Polymerizations ............................. 654
14.2.2.Step-growth Polymerization ........................ 663
14.2.3.Miscellaneous Polymers ............................ 675
14.2.4.Polymer Modification .............................. 679
14.3.Conclusion ............................................... 681
References .................................................... 682
15.Microwave-assisted Transition Metal-catalyzed Coupling
Reactions .................................................. 685
Kristofer Olofsson, Peter Nilsson, and Mats Larhed
15.1.Introduction ............................................. 685
15.2.Cross-coupling Reactions ................................. 686
15.2.1.The Suzuki-Miyaura Reaction ....................... 686
15.2.2.The Stille Reaction ............................... 700
15.2.3.The Negishi Reaction .............................. 703
15.2.4.The Kumada Reaction ............................... 704
15.2.5.The Hiyama Reaction ............................... 705
15.3.Arylation of C, N, O, S, P and Halogen Nucleophiles ...... 706
15.3.1.The Sonogashira Coupling Reaction ................. 706
15.3.2.The Nitrile Coupling .............................. 707
15.3.3.Aryl-Nitrogen Coupling ............................ 708
15.3.4.Aryl-Oxygen Bond Formation ........................ 713
15.3.5.Aryl-Phosphorus Coupling .......................... 713
15.3.6.Aryl-Sulfur Bond Formation ........................ 715
15.3.7.Aryl Halide Exchange Reactions .................... 716
15.4.The Heck Reaction ........................................ 717
15.5.Carbonylative Coupling Reactions ......................... 719
15.6.Summary .................................................. 721
Acknowledgment ................................................ 721
References .................................................... 722
16.Microwave-assisted Combinatorial and High-throughput
Synthesis .................................................. 726
Alexander Stadler and С. Oliver Kappe
16.1.Solid-phase Organic Synthesis ............................ 726
16.1.1.Introduction ...................................... 726
16.1.2.Microwave Chemistry and Solid-phase Organic
Synthesis ......................................... 727
16.1.3.Peptide Synthesis and Related Examples ............ 728
16.1.4.Resin Functionalization ........................... 729
16.1.5.Transition-metal Catalysis ........................ 734
16.1.6.Substitution Reactions ............................ 740
16.1.7.Multicomponent Chemistry .......................... 745
16.1.8.Microwave-assisted Condensation Reactions ......... 747
16.1.9.Rearrangements .................................... 748
16.1.10.Cleavage Reactions ............................... 749
16.1.11.Miscellaneous .................................... 752
16.2.Soluble Polymer-supported Synthesis ...................... 756
16.3.Fluorous-phase Organic Synthesis ......................... 762
16.4.Polymer-supported Reagents ............................... 769
16.5.Polymer-supported Catalysts .............................. 778
16.6.Polymer-supported Scavengers ............................. 781
16.7.Conclusion ............................................... 783
References .................................................... 784
17.Multicomponent Reactions Under Microwave Irradiation
Conditions ................................................. 788
Tijmen de Boer, Alessia Amore, and Romano V.A. Orru
17.1.Introduction ............................................. 788
17.1.1.General ........................................... 788
17.1.2.Tandem Reactions and Multicomponent Reactions ..... 789
17.1.3.Microwaves and Multicomponent Reactions ........... 791
17.2.Nitrogen-containing Heterocycles ......................... 793
17.2.1.Dihydropyridines .................................. 793
17.2.2.Pyridones ......................................... 797
17.2.3.Pyridines ......................................... 798
17.2.4.Dihydropyrimidinones .............................. 800
17.2.5.Imidazoles ........................................ 802
17.2.6.Pyrroles .......................................... 805
17.2.7.Other N-containing Heterocycles ................... 807
17.3.Oxygen-containing Heterocycles ........................... 809
17.4.Other Ring Systems ....................................... 812
17.5.Linear Structures ........................................ 814
17.6.Conclusions and Outlook .................................. 816
References .................................................... 816
18.Microwave-enhanced Radiochemistry .......................... 820
John R. Jones and Shui-Yu Lu
18.1.Introduction ............................................. 820
18.1.1.Methods for Incorporating Tritium into Organic
Compounds ......................................... 821
18.1.2.Problems and Possible Solutions ................... 822
18.1.3.Use of Microwaves ................................. 824
18.1.4.Instrumentation ................................... 826
18.2.Microwave-enhanced Tritiation Reactions .................. 827
18.2.1.Hydrogen Isotope Exchange ......................... 827
18.2.2.Hydrogenation ..................................... 832
18.2.3.Aromatic Dehalogenation ........................... 833
18.2.4.Borohydride Reductions ............................ 834
18.2.5.Methylation Reactions ............................. 835
18.2.6.Aromatic Decarboxylation .......................... 836
18.2.7.The Development of Parallel Procedures ............ 838
18.2.8.Combined Methodology .............................. 839
18.3.Microwave-enhanced Detritiation Reactions ................ 841
18.4.Microwave-enhanced PET Radiochemistry .................... 842
18.4.1.1 ^-labeled Compounds ............................. 843
18.4.2.18F-labeled Compounds ............................. 846
18.4.3.Compounds Labeled with Other Positron Emitters .... 852
18.5.Conclusion ............................................... 854
Acknowledgments ............................................... 854
References .................................................... 855
19.Microwaves in Photochemistry ............................... 860
Petr Klein and Vladimir Cirkva
19.1.Introduction ............................................. 860
19.2.Ultraviolet Discharge in Electrodeless Lamps ............. 861
19.2.1.Theoretical Aspects of the Discharge in EDL ....... 862
19.2.2.The Fundamentals of EDL Construction and
Performance ....................................... 863
19.2.3.EDL Manufacture and Performance Testing ........... 865
19.2.4.Spectral Characteristics of EDL ................... 866
19.3.Photochemical Reactor and Microwaves ..................... 869
19.4.Interactions of Ultraviolet and Microwave Radiation
with Matter .............................................. 877
19.5.Photochemical Reactions in the Microwave Field ........... 878
19.5.1.Thermal Effects ................................... 878
19.5.2.Microwaves and Catalyzed Photoreactions ........... 883
19.5.3.Intersystem Crossing in Radical Recombination
Reactions in the Microwave Field - Nonthermal
Microwave Effects ................................. 885
19.6.Applications ............................................. 888
19.6.1.Analytical Applications ........................... 888
19.6.2.Environmental Applications ........................ 888
19.6.3.Other Applications ................................ 891
19.7.Concluding Remarks ....................................... 891
Acknowledgments ............................................... 892
References .................................................... 892
20.Microwave-enhanced Solid-phase Peptide Synthesis ........... 898
Jonathan M. Collins and Michael J. Collins
20.1.Introduction ............................................. 898
20.2.Solid-phase Peptide Synthesis ............................ 899
20.2.1.Boc Chemistry ..................................... 900
20.2.2.Fmoc Chemistry .................................... 901
20.2.3.Microwave Synthesis ............................... 905
20.2.4.Tools for Microwave SPPS .......................... 906
20.2.5.Microwave Enhanced N-Fmoc Deprotection ............ 907
20.2.6.Microwave-enhanced Coupling ....................... 912
20.2.7.Longer Peptides ................................... 922
20.3.Conclusion ............................................... 925
20.4.Future Trends ............................................ 926
Abbreviations ................................................. 927
References .................................................... 928
21.Application of Microwave Irradiation in Fullerene and
Carbon Nanotube Chemistry .................................. 931
Fernando Langa and Pilar de la Cruz
21.1.Fullerenes Under the Action of Microwave Irradiation ..... 931
21.1.1.Introduction ...................................... 931
21.1.2.Functionalization of Fullerenes ................... 932
21.2.Microwave Irradiation in Carbon Nanotube Chemistry ....... 949
21.2.1.Synthesis and Purification ........................ 949
21.2.2.Functionalization of Carbon Nanotubes ............. 950
21.3.Conclusions .............................................. 953
References .................................................... 954
22.Microwave-assisted Extraction of Essential Oils ............ 959
Farid Chemat and Marie-Elisabeth Lucchesi
22.1.Introduction ............................................. 959
22.2.Essential Oils: Composition, Properties, and
Applications ............................................. 960
22.3.Essential Oils: Conventional Recovery Methods ............ 963
22.4.Microwave Extraction Techniques .......................... 965
22.4.1.Microwave-assisted Solvent Extraction (MASE) ...... 965
22.4.2.Compressed Air Microwave Distillation (CAMD) ...... 968
22.4.3.Vacuum Microwave Hydrodistillation (VMHD) ......... 968
22.4.4.Microwave Headspace (MHS) ......................... 969
22.4.5.Microwave Hydrodistillation (MWHD) ................ 969
22.4.6.Solvent-free Microwave Hydrodistillation (SFME) ... 969
22.5.Importance of the Extraction Step ........................ 970
22.6.Solvent-free Microwave Extraction: Concept,
Application, and Future .................................. 970
22.6.1.Concept and Design ................................ 971
22.6.2.Applications ...................................... 974
22.6.3.Cost, Cleanliness, Scale-up, and Safety
Considerations .................................... 976
22.7.Solvent-free Microwave Extraction: Specific Effects
and Proposed Mechanisms .................................. 976
22.7.1.Effect of Operating Conditions .................... 976
22.7.2.Effect of the Nature of the Matrix ................ 977
22.7.3.Effect of Temperature ............................. 979
22.7.4.Effect of Solubility .............................. 980
22.7.5.Effect of Molecular Polarity ...................... 981
22.7.6.Proposed Mechanisms ............................... 982
22.8.Conclusions .............................................. 983
References .................................................... 983
Index ......................................................... 986
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