Synthesis Of Acetophenone And Its Derivatives Under Electrochemical Conditions

Since the 21st century,with the rapid development of global economy and science and technology,human beings are increasingly aware of the importance of sustainable development.Many synthetic chemists focus on the direction of green chemistry,which is to be environmentally friendly throughout the process,to avoid the use of toxic and harmful substances,and to adopt safe and efficient synthetic routes and methods.Organic electrochemical synthesis has many notable advantages,such as the use of electrons as cleaning "reagents" that avoid the use of toxic or dangerous oxidants and reductants;In the process of electrosynthesis,electrode potential or current can be effectively controlled,so the speed of electrode reaction can be changed,side reactions can be reduced,and the yield and selectivity of the target product can be improved;The electrolysis process allows many reactions to take place under normal temperature and pressure,improving the safety and operability of synthesis,and so on.Therefore,electrochemical organic synthesis provides new ideas and powerful tools for synthetic chemists.In this paper,a series of substituted acetophenone compounds were successfully prepared by electrochemical method using phenylacetylene and ethylbenzene derivatives as reaction substrates.Most of the reported methods for the synthesis of these compounds require a variety of metal catalysts and oxidation reagents.Although good results have been obtained,their applications in organic synthesis have been limited to a certain extent by harsh reaction conditions,expensive or complex metal catalysts and the use of equivalent oxidants.By means of electrochemistry,we developed a green method to prepare various acetophenone derivatives:(1)A series of?,?-dihalogenated acetophenone compounds were successfully prepared by divided cell equipped with anion exchange membrane.The reaction can be carried out in aqueous solution at room temperature,the yield up to 94%.(2)A series of monoketones and polyketones were successfully prepared by electrochemical oxidation under oxygen conditions.It has a wide substrate scope and the yield can reach 95%.These methods can avoid the use oftoxic or expensive metal catalysts and oxidants,the reaction can be completed under normal temperature and pressure,the operation is safe and simple.At the same time,we have studied the related reaction mechanism by means of controlled experiments and cyclic voltammetry tests.The applications of the reaction products were also explored.In summary,we developed a strategy for the preparation of various acetophenone compounds under electrochemical conditions.In this method,phenylacetylene and ethyl benzene derivatives were used as reaction materials.The preparation process can be operated under normal temperature and pressure without adding metal catalyst and oxidant,which conforms to the concept of green chemistry and enriches the field of green organic synthesis.