Chirality in Supramolecular Assemblies in Supramolecular Assemblies

Causes and Consequences

Edited by

F. RICHARD KEENE Department of Chemistry, School of Physical Sciences, University ofAdelaide, Australia

WILEY Tbis edition first published 2017 © 2017 John Wiley & Sons, Ltd

Registered Office John Wiley & Sons, Ltd, TbeAtrium, Southern Gate, Chichester, West Sussex, P019 8SQ, United Kingdom

For details of our global editorial offices, for customer services and for information about how to apply for permission to reuse the copyright material in this book please see our website atwww.wiley.com.

The right of the author to be identified as the author of this work has been asserted in accordance with the Copyright, Designs and Patents Act 1988.

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by the UK Copyright, Designs and Patents Act 1988, without the prior permission of the publisher.

Wiley also publishes its books in a variety of electronic formats. Some content that appears in p1int may not be available in electronic books.

Designations used by companies to distinguish their products are often claimed as trademarks. All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners. The publisher is not associated with any product or vendor mentioned in this book.

Limit of Liability/Disclaimer of Warranty: While the publisher and author have used their best efforts in preparing this book, they make no representations or warranties with respect to the accuracy or completeness of the contents of this book and specifically disclaim any implied warranties of merchantability or fitness for a particular purpose. It is sold on the understanding that the publisher is not engaged in rendering professional services and neither the publisher nor the author shall be liable for damages arising herefrom. If professional advice or other expert assistance is required, the services of a competent professional should be sought

The advice and strategies contained herein may not be suitable for every situation. In view of ongoing research, equipment modifications, changes in governmental regulations, and the constant flow of information relating to the use of experimental reagents, equipment, and devices, the reader is urged to review and evaluate the information provided in the package insert or instructions for each chemical, piece of equipment, reagent, or device for, among other things, any changes in the instructions or indication of usage and for added warnings and precautions. The fact that an organization or Website is referred to in this work as a citation and/or a potential source of further information does not mean that the author or the publisher endorses the information the organization or Website may provide or recommendations it may make. Further, readers should be aware that Internet Websites listed in this work may have changed or disappeared between when this work was written and when it is read. No warranty may be created or extended by any promotional statements for this work. Neither the publisher nor the author shall be liable for any damages arising herefrom.

Library of Co11gress Catalogi,.g-ill-Publicatio11 data applied for

A catalogue record for this book is available from the British Library.

ISBN: 9781118867341

Set in I0/12pt Times by SPi Global, Pondicherry, India Printed and bound in Malaysia by Vivar Printing Sdn Bhd

JO 9 8 7 6 5 4 3 2 Contents

List of Contributors xi Preface xiii

1 Principles of Molecular Chirality 1 Jean-Claude Chambron and F Richard Keene 1.1 General Introduction 1 1.2 Geometrical Chirality 2 1.2.1 Origins and Description of Chirality within the Rigid Model Approximation 3 1.2.2 Dynamic and Supramolecular Chirality 18 1.3 Topological Chirality 25 1.3.1 The Molecular Graph 25 1.3.2 Topological Chirality 26 1.3.3 Topologically Relevant Molecules that are not Topologically Chiral 27 1.3.4 Topologically Chiral Milestone Molecules (Based on Covalent Bonds) 30 1.4 Conclusion 39 References 39

2 Homochirogenesis and the Emergence of Lifelike Structures 44 Pedro Cintas 2.1 Introduction and Scope 44 2.2 The Racemic State: Mirror Symmetry Breaking 45 2.2.1 Is There a Chiral Ancestor? 4 7 2.3 Asymmetric Oligomerization 49 2.3.l Homochirality and Critical Chain Length 50 2.3.2 Polymerization Models: Homochiral Peptides 53 2.3.3 Lessons from Artificial Systems 55 vi Contents

2.4 Biochirality in Active Sites 58 2.5 Conclusions 61 Acknowledgements 61 References 61

3 Aspects of and Chirality 65 Roger Bishop 3.1 Introduction 65 3.2 Crystal Space Groups 65 3.2.1 Space Group Listing 65 3.2.2 Data and Statistics 66 3.2.3 Space Group Prediction 69 3.3 Fundamentals of Crystallization for a 69 3.3.1 Racemic Compound 69 3.3.2 Solid Solution 70 3.3.3 Enantiopure Domains 70 3.3.4 Conglomerates 71 3.4 More Complex Crystallization Behavior 71 3.4.1 Crystallographically Independent Molecules 72 3.4.2 Kryptoracemates 72 3.4.3 Quasiracemates 73 3.5 Multiple Crystal Forms 74 3.5.1 Poly morphs 75 3.5.2 Solvates 79 3.5.3 Hydrates 81 3.5.4 Cocrystals 82 3.6 Conglomerates Revisited 85 3.6.1 Frequency of Conglomerate Formation 85 3.6.2 Resolution 86 3.6.3 Increasing the 87 3.6.4 Chemical Modification 89 References 90

4 Complexity of Supramolecular Assemblies 94 Jonathan A. Kitchen and Philip A. Gale 4.1 Introduction 94 4.1.1 Supramolecular Chirality 94 4.1.2 Self-Assembly 95 4.1.3 Supramolecular Chirogenesis 95 4.2 Generating Supramolecular Chirality through Assembly of Achiral Components 96 4.2.1 Supramolecular Chirality - Metallo-Helicates 96 Contents vii

4.3 Enantioselective Supramolecular Assemblies 121 4.3.l Mononuclear Bundles 123 4.3.2 Helicates 127 4.3.3 Higher Order Enantioselective Assemblies 130 4.4 Conclusions and Future Outlook 134 References 134

5 Chirality in the Host-Guest Behaviour of Supramolecular Systems 142 Nicholas H. Evans and Paul D. Beer 5.1 An Introduction to Chiral Recognition and its Importance 142 5.2 Chiral Hosts for Chiral Guests 143 5 .2.1 Theory of Chiral Recognition 143 5.2.2 Chiral Crown Ethers for Chiral Ammonium Cations 143 5.2.3 Hosts for Chiral Anions 145 5.2.4 Hosts for Chiral Zwitterions and Neutral Molecules 153 5.3 Conclusions: Summary and Future Directions 155 References 156

6 Chiral Influences in Functional Molecular Materials 159 David B. Amabilino 6.1 Introduction 159 6.2 Functional Molecular Materials in Different States 161 6.2.1 Crystals 161 6.2.2 Liquid Crystals 162 6.2.3 Gels 164 6.3 Switching 168 6.4 Conducting Materials 171 6.5 Magnetic Materials 173 6.6 Sensors 177 6.7 Conclusions and Outlook 180 Acknowledgements 181 References 181

7 Chirality in Network Solids 190 David R. Turner 7 .1 Introduction 190 7.2 Chirality in Inorganic Network Solids 191 7 .3 Synthesis of Chiral Coordination Polymers 192 7.3.l Chiral Induction, Templating and Symmetry Breaking 192 7.3.2 Incorporation of Small Chiral Co-Ligands 195 7.3.3 Design and Application of Chiral Ligands 199 7 .3 .4 Post-Synthetic Modification 206 viii Contents

7.4 Applications of Chiral Coordination Polymers 207 7.4.1 Enantioselective Catalysis 207 7.4.2 Enantioselective Separations 208 7.5 Summary and Outlook 209 References 210

8 Chiral Metallosupramolecular Polyhedra 218 Jack K. Clegg and John C. McMurtrie 8.1 Introduction 218 8.2 Basic Design Principles 219 8.3 Chiral Polyhedra from Achiral Components 221 8.3.1 Tetrahedra 222 8.3.2 Higher Order Polyhedra 229 8.4 Stereochemical Communication 231 8.4.1 Stereocontrol through Ligand Modification 232 8.4.2 Mechanisms of Interconversion between 234 8.5 Resolution of Racemic Metallo-Supramolecular Polyhedra 236 8.6 Chiral Polyhedra from Chiral Molecular Components 239 8.7 Conclusions and Outlook 250 References 251

9 Chirality at the Solution/Solid-State Interface 257 Iris Destoop and Steven De Feyter 9.1 Self-Assembly at the Solution I Solid-State Interface 257 9.2 Chirality Expression at the Solution/ Solid-State Interface 258 9.2.1 Enantiopure Molecules at the Solution/ Solid-State Interface 258 9.2.2 Racemates at the Solution I Solid-State Interface 259 9.2.3 Achiral Molecules at the Solution/ Solid-State Interface 261 9.2.4 Other Factors Influencing 2D Chirality 263 9.3 Chiral Induction I Amplification at the Solution I Solid-State Interface 266 9.3.1 Sergeants and Soldiers 266 9.3.2 Chiral Auxiliaries 269 9.3.3 Chiral Solvents 272 9.3.4 Majority Rules 277 9.3.5 Magnetic Fields 277 9.4 Towards Applications 278 9.4.1 at the Solution I Solid-State Interface 278 9.4.2 Enantioselective Adsorption at the Solution I Solid-State Interface 280 9.5 Conclusions 282 References 282 Contents ix

10 Nanoscale Aspects of Chiral Nucleation and Propagation 285 Edward G. Latter and Rasmita Raval 10.1 Introduction 285 10.1.l Chirality at Surfaces 286 10.1.2 Tracking Chiral Nucleation at Surfaces 286 10.2 Systems of Discussion 288 10.2.1 System 1: Co-TPP on Cu( 110)- Chirogenesis via Intermolecular Interactions 288 10.2.2 System 2: Enantiopure and Racemic Mixtures of a Chiral Bis-lactate - Chiral Segregation Nipped in the Bud 293 10.2.3 System 3: Tartaric Acid on Cu(l 10): Highly Nonlinear Chiral Crystallization 298 10.3 Conclusions 303 References 304

11 Chirality in Organic Hosts 307 Daniel Fankhauser and Christopher J. Easton 11.1 Introduction 307 11.2 Chiral Hosts in Analytical Applications 307 11.3 Chiral Hosts in Asymmetric Reactions 313 11.3. l Native Chiral Hosts 315 11.3.2 Hosts Modified with Achiral Substituents 322 11.3.3 Hosts Modified with Chiral Substituents 329 11.3.4 Hosts Modified with Metal-Coordinating Ligands 332 11.4 Conclusion 337 Acknowledgements 338 References 338

12 Chirality Related to and Enzymes in Organic Synthesis 343 Declan P Gavin and Anita R. Maguire 12.1 Introduction 343 12.2 Biocatalysis 344 12.2.1 Historical Context 344 12.2.2 Importance of Biocatalysis 344 12.2.3 Biocatalytic Methodologies 345 12.2.4 Enzyme Classes 345 12.2.5 Advantages and Disadvantages of Biocatalysis 346 12.2.6 Whole Cells/Isolated Enzymes 348 12.3 Biocatalytic Methodologies: Kinetic/Dynamic and Asymmetric Transformations I Chemoselective Desymmetrizations 348 12.3. l Kinetic Resolution 349 12.3.2 Dynamic Kinetic Resolution 349 x Contents

12.3.3 Asymmetric Transformations 350 12.3.4 Chemoselective Desymmetrizations 350 12.4 Optimization of Biocatalyst Performance 351 12.4.1 Organic Solvents 351 12.4.2 Immobilization 352 12.4.3 Ionic Liquids 352 12.5 Protein Engineering 352 12.5.1 Directed Evolution and Semi-Rational Design 354 12.5.2 Rational Design 355 12.6 Hydrolysis/Reverse Hydrolysis 356 12.6.1 Hydrolases in Biocatalysis - An Overview 356 12.6.2 Esterification/Hydrolysis of Esters 358 12.6.3 Epoxide Hydrolases 363 12.6.4 Hydrolases in the Resolution of Chiral Amines 363 12.7 Redox Reactions 366 12.7.1 Cofactors 366 12.7.2 Reduction of Ketones 367 12.7.3 Aldehyde Reductions 370 12.7.4 Reductive Aminations 370 12.7.5 Reduction ofC=C Bonds 373 12.7.6 Enantioselective Oxidation/Reduction Cascade Reactions 374 12.7.7 Oxidases 374 12.7.8 Other Oxidations 376 12.8 C-C and Other C-X Bond Formation 380 12.8.1 C-C Bond Formation 380 12.8.2 Halohydrin Dehalogenases 382 12.8.3 Nitrile Hydratases 383

12.8.4 Addition ofHp!NH3 to C=C Bonds 384 12.9 Future and Outlook 385 References 385

Index 407 List of Contributors

David B. Amabilino, School of Chemistry, University of Nottingham, Nottingham, United Kingdom

Paul D. Beer, Inorganic Chemistry Laboratory, University of Oxford, Oxford, United Kingdom

Roger Bishop, School of Chemi~, The University of New South Wales, Sydney, Australia

Jean-Claude Chambron, Institut de Chimie Moleculaire de l'Universite de Bourgogne, Dijon, France

Pedro Cintas, Departamento de Qufmica Organica e Inorg:inica, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain

Jack K. Clegg, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia

Steven De Feyter, Division of Molecular Imaging and Photonics, Department of Chemistry, KU Leuven-University of Leuven, Leuven, Belgium

Iris Destoop, Division of Molecular Imaging and Photonics, Department of Chemistry, KU Leuven-University ofLeuven, Leuven, Belgium

Christopher J. Easton, Research School of Chemistry, Australian National University, Canberra, Australia xii List of Contributors

Nicholas H. Evans, Department of Chemistry, Lancaster University, Lancaster, United Kingdom

Daniel Fankhauser, Research School of Chemistry, Australian National University, Canberra, Australia

Philip A. Gale, Chemistry, University of Southampton, Southampton, United Kingdom

Declan P. Gavin, Department of Chemistry, Synthesis and Solid State Pharmaceutical Centre, University College Cork, Cork, Ireland

F. Richard Keene, Department of Chemistry, School of Physical Sciences, University of Adelaide, Adelaide, Australia

Jonathan A. Kitchen, Chemistry, University of Southampton, Southampton, United Kingdom

Edward G. Latter, Surface Science Research Centre and the Department of Chemistry, University of Liverpool, Liverpool, United Kingdom

Anita R. Maguire, School of Pharmacy and Department of Chemistry, Analytical and Biological Chemistry Research Facility, Synthesis and Solid State Pharmaceutical Centre, University College Cork, Cork, Ireland

John C. McMurtrie, School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, Australia

Rasmita Raval, Smface Science Research Centre and the Department of Chemistry, University of Liverpool, Liverpool, United Kingdom

David R. Turner, School of Chemistry, Monash University, Clayton, Australia Preface

The origins of what is now called supramolecular chemistry have been somewhat disparate, arising in part from studies of the chemistry of macrocycles (a development of naturally occurring analogues), spherands and carcerands, and cryptates ... but the award of the 1987 Nobel Prize to Donald Cram, Charles Pedersen and Jean-Marie Lehn in many ways gave it a consolidated focus and led to its emergence as a field that retains vigorous and distinctly multidisciplinary activities. Supramolecular chemistry - defined by Lehn as "the chemistry of molecular assemblies and of the intermolecular bond" - deals with the organization of molecules into defined assemblies using noncovalent interactions, includ­ ing weaker and reversible associations such as hydrogen bonds, II-II interactions, dispersion interactions, hydrophobic and solvophobic effects, and metal-ligand interactions. The aspect of within such chemical architectures, and in particular chirality, is of very special interest as it impacts on considerations of molecular recognition, the development of functional materials, the vexed question of homochirality, nanoscale effects of interac­ tions at interfaces, biocatalysis and enzymatic catalysis, and applications in organic synthesis. This book is intended to address the nature of the phenomenon of chirality in its broadest sense, noting the change in its nuances and subtlety in the progression from simple indi­ vidual molecules to molecular assemblies, and to show the manifestations of chirality in the synthesis, properties, and applications of supramolecular systems, emphasizing their multidisciplinary importance. The book is essentially divided in to four broad parts. The first constitutes an introduction to chirality: Chapter l develops the concept of chirality from rigid isolated molecules through to assemblies of molecules (in supramolecular entities), to topological chirality. Chapter 2 discusses chirogenesis and the phenomenon of homochirality (loss of parity) in the development of naturally occurring polymers (including nucleic acids and polypeptides) - and its consequences for the formation of artificial supramolecular xiv Preface

aggregates. Chapter 3 provides an overview of chiral aspects arising in the crystallization of small organic molecules - principles that are applicable to all classes of molecules, includ­ ing supramolecular assemblies. The second part is predominantly (but not exclusively) centered on metallosupramolecular chemistry. By the use of examples, Chapter 4 addresses the diversity \if supramolecular assemblies - and in particular metallosupramolecular assemblies - and describes the com­ plexity of chiral structures and their construction through self-assembly procedures. Chapter 5 describes the role of chirality in molecular recognition and host-guest systems. Chapter 6 develops the notion that unique characteristics can be built into supramolecular assemblies because of features of chirality - characteristics that can lead to functional properties of such materials. Chapter 7 addresses bulk homochiral solids formed using chiral reagents - either by direct incorporation, or by templating or induction, during synthesis. Chapter 8 considers the basic design principles that underpin the construction of metallosupramolecular polyhedra. The third part is devoted to chirality at interfaces. Chapter 9 focuses on chirality expression and amplification at solution I solid-state inte1faces, and applications such as heterogeneous catalysis and chiral separations. Chapter 10 addresses the initiation of chiral suprastructures on surfaces, and their modeling by high-resolution experimental methods and theoretical calculations. The fourth part addresses chirality in organic hosts, and in biological I enzymatic sys­ tems: organic hosts are used in analytical chemistry to separate racemic guest mixtures or simply to distinguish , and chiral hosts can function as catalysts in asymmetric reactions - Chapter 11 reviews particular features and applications of chiral organic host systems based primarily on cyclodextrins, calixarenes, and crown ethers in this regard. Chapter 12 stresses the enormous potential of microorganisms and enzymes as catalysts in asymmetric synthesis for controlling the stereochemical outcome of reactions, and dis­ cusses the use of whole cells and isolated enzymes as an attractive option for the chemical industry. It is always understood that supramolecular chemistry is so diverse that one book cannot be totally equitable in its coverage of all aspects of the field. This book attempts to address some of the major aspects authoritatively and highlight important cmTent thrusts. It will be useful to researchers working with chiral supramolecular assemblies, and will hopefully draw others with an existing interest in supramolecular systems to a further appreciation of the importance of chirality in the field, as seen through contributions of experts in their respective parts of that firmament.

F. Richard Keene Adelaide, Australia