Contents

#### **Preface XI**


#### **X** Contents


Preface

efficiently and safely.

Currently, the expression "Green Chemistry" is an omnipresent subject matter in both aca‐ demic and innovative chemical companies. All over the world, efforts are dedicated to initia‐ tives to make chemical processes of manufacturing more sustainable, more energy efficient, more biocompatible, more environmentally benign, less waste-generating, healthier, and more resource-efficient; all these issues nowadays are jointly discussed as "Green Chemistry." Today, the modern chemist is aware of the fact that research and development always have to meet the ancient Latin principle "Quidquid agis, prudenter agas, et respice fines!" ("whatever you do, do it virtuously, and consider the consequences"). This principle implies that every new process in the development has to take into account the possible impacts on the current and future status of humankind, the environment, and, most of all, the fate of future generations. Translated into our present world, chemists and engineers should act in accordance with the 12 well-known principles of Anastas and Warner, which honestly can be regarded as the basic law of current and future chemical manufacturing practice. In a nutshell, these 12 principles show us the way chemistry in general can get rid of its bad pub‐ lic reputation, which brands it as "toxic," "polluting," "corrosive," "lethal," "stinking," and so on. In this context, Anastas and Warner postulated that chemistry can definitely become "green," when fundamental paradigm shifts are implemented in its manufacturing process‐ es. This includes switching from exploiting limited resources of fossil origin to profiting from the abundance of renewable feedstocks and the development of atom-economic proc‐ esses, generating "zero waste," producing materials in an intrinsically safe way, designing energy-efficient processes, or using harmless catalysts. Especially the last aspect, namely the use of benign and efficient catalysts, provides the direct link between "green chemistry" and the nature's approaches of chemical manufacturing; here, "biocatalysts," hence enzymes, are used to efficiently, selectively, and sustainably transform diverse raw materials into desired marketable end-products. After completing their task, enzymes undergo biodegradation within the nature's closed material cycles. Regarding strategies for producing materials in an intrinsically safe way, one can refer to the emerging field of "flow chemistry" using ad‐ vanced microreactor systems, which allow carrying out typically highly hazardous reactions

The book at hand, "Green Chemistry," was compiled to mirror all the upcoming discussed aspects, which will make chemistry more sustainable. Carefully selected authorships from different countries contributed well-chosen, specific chapters to this publication endeavor. The introduction section written by Hosam Saleh and Martin Koller provides the embed‐ ding of different chemical techniques into the principles defined by Anastas and Warner in order to provide a fundamental overview on what "Green Chemistry" should aim at. Qur‐ aishi Mumtaz presents the new aspects of using ionic liquids as "green" corrosion inhibitors to protect industrial metals and alloys. Perveen Shagufta makes us familiar with the ques‐ tion how "green chemistry" can be implemented in the production of desired anticancer

Chapter 9 **Green Approach in Click Chemistry 171** Sachin P. Shirame and Raghunath B. Bhosale
