Advances in Microwave Chemistry

Book Preface

Modern technology that facilitates the development of new science in a number of ways is the topic of current interest. Highly expeditious preparation and testing of new molecules have been demonstrated in recent years. For example, microwave-assisted reactions have been used extensively for the synthesis of privileged mol-ecules with known and unknown structures. In many experiments, the superiority of microwave-assisted chemistry over the conventional heating method has been observed and proved. A few authors have attempted to explain the cause of the accel-eration rates, stereoselectivity of the products, cleaner synthesis, increased yields, and the environmentally benign nature of these reactions that are associated with domestic and automated microwave-induced reactions. It has been argued that the reactants absorb energy, thereby permitting them to activate at the molecular level and helping to form a non-equilibrium situation, allowing molecules to transfer heat into other components. The cause of acceleration of numerous reactions by the microwave-induced method has expanded this field. However, both thermal and non-thermal microwave effects are proposed for rapid reactions that are observed under microwave-induced methods compared to conventional heating. The synthesis of molecules under microwave irradiation is one of the most attractive areas of current research in chemistry, both academic and industrial. In many instances, the mol-ecules synthesized by microwave-induced reactions have demonstrated reasonable pharmacological activities.
Microwave-induced methods are not restricted to chemistry. Their relevance has expanded to other areas of science: medicine, biotechnology, biology, and engineer-ing. Significant progress has been made in these areas using microwave technology. Some of the methods described herein are new and, therefore, the scope in these areas is unlimited.
The diversity of microwave-assisted chemistry as presented in this book is excep-tionally high. The chapters are not organized based upon a specific subject matter. Rather, they are numbered in the order of acceptance date. Authors from Argentina, Brazil, China, India, and the United States have contributed chapters in this book.
Each of the twelve chapters presented in this book aimed to provide the contem-porary aspects of advances in microwave-mediated science.
In Chapter 1, Jimenez, Zanin, Ferreira, Araú jo, and Porto described recent appli-cations of microwave radiation in biocatalysis. The synergism of the microwave radiation microbial cells, and enzymes is claimed to produce molecules that are of interest to chemistry, biology, and natural products, as well as the biodegradation of recalcitrant xenobiotic compounds. In Chapter 2, Alvarez, Lorenzetti, Acebal, Lista, and Domini demonstrated microwave-assisted sample preparation. In Chapter 3, Gomez, Aguinaga, LLmas, Garrido, Acebal, and Domini reported green microwave-mediated processes for degradation and microextraction. In Chapter 4, Wang and Zhong advanced the preparation and application of functional rare earth (RE)-based micro/nanomaterials using the microwave. In Chapter 5, Batra, Panwar, Pratap, and Nath described microwave-accelerated synthesis and functionalization of numerous oxygen-containing six-membered heterocyclic compounds: benzopyrans, 1, 3-diox-anes, 4H- pyrans, spiropyrans, chromones, xanthenes, and coumarins as well as some fused six-membered oxygen heterocycles. In Chapter 6, Xu investigated the origin of selectivities in the microwave-mediated organic reactions. Diverse selec-tivities, including chemoselectivity, regioselectivity, diastereoselectivity, and enanti-oselectivity in organic reactions were discussed under the microwave-assisted and conventional heating conditions. In Chapter 7, Brahmachari reported and updated microwave-induced Hirao and Kabachnik-Fields phosphorus-carbon bond forming reactions. Various examples of unusual carbon-phosphorous compounds were shown for the first time. In Chapter 8, Seelaboyina, Kumar, and Singh studied the microwave-induced synthesis of absorber layer materials for thin film photovoltaic application. Recent progress in the microwave-assisted synthesis of size and composition defined CIS, CIGS, and CZTS nanopowder for the absorber layer in TFPV application is reported. In Chapter 9, Shukla, Purohit, and Chakraborti studied microwave-assisted transition metal-catalyzed synthesis of pharmaceutically important heterocycles. Examples were provided where different heterocyclic scaffolds are obtained in the presence of a transition metal-based catalyst under microwave heating compared to that obtained by conventional heating. In Chapter 10, Bandyopadhyay and Banik dis-cussed the microwave-induced synthesis of versatile important lactams. In Chapter 11, Sahoo, Banik, and Panda demonstrated the use of microwave technology in synthe-sizing various organic compounds following an eco-friendly route. In Chapter 12, Sahoo, Banik, and Panda investigated a green chemistry approach for the synthesis of drugs and drug candidates.
After reading this book, one may become convinced that the microwave has no boundary in science: it can be applied to almost all types of discoveries. In conclu-sion, this book provides an exploratory, as well as a concise and critical understand-ing of the significances in microwave research. Therefore, this book will be useful for scientists particularly for chemists, biologists, biotechnologists, and engineers who are working in diverse and specific new research areas.
We take the opportunity to thank the authors for their highly significant and excep-tional contributions. Thanks are also due to Ms. Hilary Lafoe and Taylor & Francis who have realized that such a book on microwave chemistry will be extremely useful for researchers around the world.

Bimal Krishna Banik Debasish Bandyopadhyay