SOLID SUPPORTS AND CATALYSTS IN ORGANIC SYNTHESIS

Transcription

1 SOLID SUPPORTS AND CATALYSTS IN ORGANIC SYNTHESIS Editor Professor K. SMITH, M.SC,PhD. Head of Department of Chemistry University College of Swansea Wales ELLIS HORWOOD PTR PRENTICE HALL NEW YORK LONDON TORONTO SYDNEY TOKYO SINGAPORE

2 Contents List of contributors ix Preface xiii Part I Structures and nature of solids used as supports/catalysts 1 Inorganic Supports and catalysts an overview P. Diddams 1.1 General considerations Silica Alumina Carbon Clay minerals Zeolites Conclusion 36 Bibliography 37 References 39 2 Organic Supports an overview J. M. Maud 2.1 Introduction The preparation of organic polymeric supports The 'nature' of the polymeric support Conclusions 58 References 59 Part II Traditional organic reactions aided by solid supports or catalysts 3 Reactions assisted by amorphous inorganic solids a survey M. Butters 3.1 Introduction Selective methods for the preparation of esters Base catalysis for the activation of 'OH acids' Silica gel as a medium for the formation and selective cleavage of acetals and ketals Reagents and catalysts for electrophilic Substitution of aromatic and heterocyclic Compounds 76

3 vi Contents 3.6 Electrocyclic reactions Nucleophilic substitutions by oxygen and nitrogen nucleophiles' Elimination reactions over solid supports Selective reductions over solids Oxidation over solids Allylic chlorination over silica 96 References 97 4 Reactions assisted by clays and other lamellar solids a survey J. A. Ballantine 4.1 Introduction Acidity of clays and types of clay catalysts Preparation of clay catalysts Clay-catalysed organic reactions where the catalyst is acting essentially as a solid acid Clay-supported inorganic reagents Graphite intercalation Compounds Conclusion 122 References Zeolite-assisted organic synthesis a survey M. Butters 5.1 Introduction Chemical dehydration; formation of alkenes, enamines, acetals and Condensed heterocycles Preparation of esters, ethers, and amides assisted by removal of small reactants from reaction equilibria using zeolite molecular sieves Separation of isomers and closely related Compounds from a mixture Selective photorearrangements within zeolite cavities Electrocyclic reactions Shape selective electrophilic aromatic Substitution Control of alkene addition reactions Isomerization and oligomerization of alkenes Nucleophilic substitutions of epoxides and alkyl halides Reduction reactions Oxidation reactions Photochlorination of alkanes 165 References Reactions involving polymeric resins a survey J. M. Maud 6.1 Introduction Polymer-supported organic Substrates Polymer-supported reagents and catalysts Conclusions 188 References 188

4 Contents vii Part III Solids in biological chemistry and molecular biology 7 Solid phase peptide synthesis J. S. Davies 7.1 Introduction Synthetic strategy for peptide synthesis The automated solid phase protocol Alternative approaches to solid phase synthesis simultaneous (or parallel) multiple peptide synthesis (SMPS) Selected examples of Oligopeptide synthesis 216 References Solid phase oligonucleotide synthesis H. A. White 8.1 Introduction Applications of oligonucleotides General strategy for oligonucleotide synthesis Phosphotriester synthesis Phosphoramidite synthesis Hydrogen phosphonate and 'phosphorothioite' syntheses The solid phase Oligonucleotide purification Synthesis of oligoribonucleotides Problems in oligonucleotide synthesis Preparation of oligonucleotide mixtures Preparation of modified oligonucleotides and variant oligonucleotides Future developments 249 References Immobilized biocatalysts J. M. Woodley 9.1 Introduction Biological catalysis Biocatalyst immobilization Techniques for immobilization Implication of introducing a solid Support Uses of immobilized biocatalysts Concluding remarks 268 References 269 Part IV Individual applications 10 Hydrogenation and hydrogenation catalysts M. E. Fakley and F. King 10.1 Background Practical considerations New heterogeneous hydrogenation catalysts Functional group reductions Future trends 284

5 viii Contents 10.6 Appendices 284 References Designing micro-reactors a personal account P. Laszlo 11.1 Introduction From prebiotic chemistry to present-day frontiers of chemistry The relevance of rocketry and drunkenness to the design of a new oxidizing reagant Concentration effects by clays Catalysis by clays The catalytic sites Conclusions. The significance of clays in a wider context 298 Acknowledgements 298 References Microwave activation of reactions on organic solid supports G. Bram, A. Loupy and D. V illemin 12.1 Microwaves Application of commercial microwave ovens to organic synthesis in Solution Solid materials under microwaves Microwave-activated organic synthesis on solid supports 312 References 324 Index 327