The present book is intended to provide an important overview of various processes and procedures devoted to the eco-sustainable syntheses of fine chemicals. The contributions of catalysis as well as of ultrasonic and microwave irradiation are thoroughly examined. Nevertheless, the key role of solvents has also been considered. In addition, chapters have been dedicated to the application of a simple reaction to the synthesis of complex molecules. Thus, I believe that this book represents an important contribution to eco-sustainable chemistry and should be of interest for both young and senior researchers involved in this field.