Studies On The Synthesis Of Benzo[b]furans

Many benzo[b]furans are biologically active components isolated from plants or compounds synthesized. So the chemistry of benzo[b]furan derivatives has received much attention.The first part of this paper focuses on the studies of the development in synthesizing 2-arylbenzo[b]furan compounds and their synthetic methods. Major synthetic strategies utilized include the traditional methods, palladium-based catalyzed, copper-based catalyzed and other noble metals catalyzed. The traditional methods have played very important role in preparing benzo[b]furans, these traditional methods are often multi-step reactions, limited to a particular substrate, and do not tolerate a variety of functional groups. In comparison to the traditional methods, these palladium and other noble metals catalyzed protocols offer increased functional group tolerance and improved yields of the desired benzo[b]furan. But these noble metals are too expensive to enlarge and industrial product. In recent years, people have been interested in developing the cheap copper-catalyzed cross-coupling reactions and get good results. But it also limited to the substrate and the expensive reagents.In the second part, we discovered that in the presence of Et₃N, using K₂CO₃ as the base and catalyzed by [Cu(phen) (PPh₃)₂]NO₃ ,we synthesized a series of benzo[b] furans successfully. This method not only the substrates prepared easily and using cheap reagents but also remain the reactions of choice in large and industrial scale reactions.