Ball Milling Towards Green Synthesis Applications, Projects, Challenges RSC Green Chemistry Editor-in-Chief: Professor James Clark, Department of Chemistry, University of York, UK Series Editors: Professor George A Kraus, Department of Chemistry, Iowa State University, Ames, Iowa, USA Professor Andrzej Stankiewicz, Delft University of Technology, The Netherlands Professor Peter Siedl, Federal University of Rio de Janeiro, Brazil Professor Yuan Kou, Peking University, China Titles in the Series: 1: The Future of Glycerol: New Uses of a Versatile Raw Material 2: Alternative Solvents for Green Chemistry 3: Eco-Friendly Synthesis of Fine Chemicals 4: Sustainable Solutions for Modern Economies 5: Chemical Reactions and Processes under Flow Conditions 6: Radical Reactions in Aqueous Media 7: Aqueous Microwave Chemistry 8: The Future of Glycerol: 2nd Edition 9: Transportation Biofuels: Novel Pathways for the Production of Ethanol, Biogas and Biodiesel 10: Alternatives to Conventional Food Processing 11: Green Trends in Insect Control 12: A Handbook of Applied Biopolymer Technology: Synthesis, Degradation and Applications 13: Challenges in Green Analytical Chemistry 14: Advanced Oil Crop Biorefineries 15: Enantioselective Homogeneous Supported Catalysis 16: Natural Polymers Volume 1: Composites 17: Natural Polymers Volume 2: Nanocomposites 18: Integrated Forest Biorefineries 19: Sustainable Preparation of Metal Nanoparticles: Methods and Applications 20: Alternative Solvents for Green Chemistry: 2nd Edition 21: Natural Product Extraction: Principles and Applications 22: Element Recovery and Sustainability 23: Green Materials for Sustainable Water Remediation and Treatment 24: The Economic Utilisation of Food Co-Products 25: Biomass for Sustainable Applications: Pollution Remediation and Energy 26: From C-H to C-C Bonds: Cross-Dehydrogenative-Coupling 27: Renewable Resources for Biorefineries 28: Transition Metal Catalysis in Aerobic Alcohol Oxidation 29: Green Materials from Plant Oils 30: Polyhydroxyalkanoates (PHAs) Based Blends, Composites and Nanocomposites 31: Ball Milling Towards Green Synthesis: Applications, Projects, Challenges How to obtain future titles on publication: A standing order plan is available for this series. A standing order will bring delivery of each new volume immediately on publication. For further information please contact: Book Sales Department, Royal Society of Chemistry, Thomas Graham House, Science Park, Milton Road, Cambridge, CB4 0WF, UK Telephone: þ44 (0)1223 420066, Fax: þ44 (0)1223 420247 Email: [email protected] Visit our website at www.rsc.org/books Ball Milling Towards Green Synthesis Applications, Projects, Challenges Edited by Brindaban Ranu University of Jadavpur, Jadavpur, Kolkata, India Email: [email protected] Achim Stolle University of Jena, Jena, Germany Email: [email protected] RSC Green Chemistry No. 31 Print ISBN: 978-1-84973-945-0 PDF eISBN: 978-1-78262-198-0 ISSN: 1757-7039 A catalogue record for this book is available from the British Library r The Royal Society of Chemistry 2015 All rights reserved Apart from fair dealing for the purposes of research for non-commercial purposes or for private study, criticism or review, as permitted under the Copyright, Designs and Patents Act 1988 and the Copyright and Related Rights Regulations 2003, this publication may not be reproduced, stored or transmitted, in any form or by any means, without the prior permission in writing of The Royal Society of Chemistry or the copyright owner, or in the case of reproduction in accordance with the terms of licences issued by the Copyright Licensing Agency in the UK, or in accordance with the terms of the licences issued by the appropriate Reproduction Rights Organization outside the UK. Enquiries concerning reproduction outside the terms stated here should be sent to The Royal Society of Chemistry at the address printed on this page. The RSC is not responsible for individual opinions expressed in this work. The authors have sought to locate owners of all reproduced material not in their own possession and trust that no copyrights have been inadvertently infringed. Published by The Royal Society of Chemistry, Thomas Graham House, Science Park, Milton Road, Cambridge CB4 0WF, UK Registered Charity Number 207890 For further information see our web site at www.rsc.org Foreword Ball milling creates stress on substances. Solids break, and the resulting particles are modified in shape and size. Defects are induced and surface areas enlarged. Consequently, ball milling is highly relevant for various technological fields including mineral processing, materials engineering, and biomass degradation. In most of such applications the milling process is used for a particle size reduction. However, the energy induced by the mechanical treatment has other effects as well. On the molecular level, for example, the arrangements of chemical structures can change leading to products with altered properties. The potential of such mechanochemical approaches and the implications in utilizing them in modern organic syn- thesis are nicely illustrated by the excellent contributions collected in the book edited by Stolle and Ranu. Many of the discussed reactions are solvent- free leading to ecological and economical advantages over existing tech- nologies providing the same products. Further benefits are recognized when comparing the energy efficiency of ball milling with other activation modes. Apparently, ball milling can be applied in a number of bond-forming pro- cesses, and various standard organic transformations (such as oxidations, reductions, and peptide formations) benefit from the use of this mechano- chemical technique. Both low-molecular-weight compounds as well as polymers undergo specific chemical modifications in ball mills. Surprising observations have been made in both metal-catalyzed and organocatalytic C–C-bond formations including asymmetric versions thereof. Liquid-assisted grinding and kneading have proven advantageous for the preparation of co- ordination compounds. Being aware of the technological and process para- meters is essential for achieving optimal results in synthetic transformations performed in ball mills. Although mechanochemical activations have already been utilized for a long time, the advantages of applying ball mills in targeted organic synthesis RSC Green Chemistry No. 31 Ball Milling Towards Green Synthesis: Applications, Projects, Challenges Edited by Brindaban Ranu and Achim Stolle r The Royal Society of Chemistry 2015 Published by the Royal Society of Chemistry, www.rsc.org vii viii Foreword has largely remained unrecognized until recently. The growing awareness of environmental implications of chemical processes and the search for greener solutions have led to a change, and today ball milling results are more present in the community than ever. Gaining a deeper understanding of the underlying mechanistic principles leading to mechanochemical acti- vations and finding new reaction pathways resulting in products inacces- sible by other means will further expand the synthetic ball milling opportunities. This book will initiate new thought processes and promote the imple- mentation of ball milling as a modern synthetic technique in existing lab structures. Experts in academia and industry as well as interested new- comers will benefit from the timely presentations collected by Stolle and Ranu, and I congratulate both editors and authors for their stimulating contributions. Carsten Bolm Aachen, Germany Preface During the last few years ball milling has emerged as a powerful tool in effecting various chemical reactions in a relatively green way by reducing the amount of solvent and operating at close to ambient temperature by appli- cation of mechanical energy. However, compared to other alternative forms of energy such as microwave and ultrasound, ball milling is still not familiar as a synthetic tool to a wide section of chemists and activity is limited to a comparatively small number of groups. Thus, the objective of this book is to create a general awareness of the importance of ball milling in chemical transformations among all section of readers including students, teachers and researchers. This book, entitled Ball Milling Towards Green Synthesis: Applications, Projects, Challenges, covers the current developments in the application of ball milling for various chemical transformations such as carbon–carbon and carbon–heteroatom bond formation, oxidation– reduction, organocatalytic reaction, dehydrogenative coupling, synthesis of peptide, polymeric materials, etc. highlighting its green aspects, scope and future prospects. This book also includes a chapter describing its origin, technological background and challenges. We gratefully acknowledge the co-operation from all those eminent and active scientists who contributed chapters to this book and the support and guidance from the staff at the Royal Society of Chemistry. We hope this book will be able to provide basic information regarding ball milling and its application in chemical synthesis and thus will be useful to a wide section of chemists including students and researchers associated with academy and industry. Brindaban C. Ranu Achim Stolle RSC Green Chemistry No. 31 Ball Milling Towards Green Synthesis: Applications, Projects, Challenges Edited by Brindaban Ranu and Achim Stolle r The Royal Society of Chemistry 2015 Published by the Royal Society of Chemistry, www.rsc.org ix Contents Chapter 1 Carbon–Heteroatom Bond