Electrochemical Synthesis of Heterocycles via Cascade Reactions

Background: Cascade reactions are well-known as powerful process to design complex molecular structures from simple and cheap starting compounds by using two or more reactions in a single consecutive transformation. These reactions, forming a number of bonds by one operation, are useful for the creation of polycyclic and spirocyclic compounds. Thus, cascade reactions play important role in modern organic chemistry. The importance of cascade reactions are based not only on contemporary demands for more efficient and less labour-consuming methodologies for the synthesis of pharmaceuticals and other fine chemicals, but also from growing necessity to coincide the modern environmental demands. The development of electrosynthesis during last few decades have created a lot of important synthetic methodologies in the field of modern organic synthesis. Electroorganic synthesis is known as an environmentally benign methodology for many redox processes, since utilization of reagents with expressed toxicity are substituted by electric current, and the quantity of waste thus, tends to be considerably diminished. The electrochemical step is often only the first reaction in complex multi-step process, but it plays important role in producing starting reactive intermediates. Thus, organic electrochemistry offers remarkable alternatives to usual organic synthetic methods and creates a modern tool for carrying out organic synthesis. Objective: The review deals with the last trends of the application of electrochemical methods to start the assembling of heterocyclic compounds by cascade reactions.