Study On The Reaction Of 1,3 - Dipolar Cycloaddition Of 4 - Aryl - NH3 - 1,2,3 - Triazole With P - Toluenesulfonic Acid Assisted Nitropene And Sodium Azide

1,2,3-triazole compounds have been widely applied in diverse areas of chemistry such as materials science, medicinal chemistry, synthetic organic chemistry and so on. However, 1,2,3-triazole compounds and their derivatives do not exist in nature and such compounds only can be prepared by organic synthesis methods. And many methods to access 1,2,3-triazole compounds since the Huisgen-1,3-dipolar cycloaddition reaction in 1963 has been developed, such as transition metal catalyzed, small organic molecules catalyzed and thermal cycloaddition. Copper and ruthenium catalyzed reactions are more mature, more obviously regioselective in the transition metal catalyzed cycloaddition reactions. Most of copper catalyzed 1,3-dipolar cycloaddition of alkynes with organic azide generated 1,4-disubstituted 1,2,3-triazoles, the ruthenium catalyzed reactions are more inclined to get 1,5-disubstituted 1,2,3-triazoles. Another metals (palladium, iridium, titanium, zinc) catalyzed 1,3-dipolar cycloaddition reactions also have a great advantage. With the need of environment and the development of green chemistry, the non-metal catalyzed organic synthesis chemistry has attracted ever-increasing attention and gained a lot of fruitful results in recent years.4-aryl-NH-1,2,3-triazole compounds have great application values which have a very good biological activity and can continue to synthesize other triazole derivatives. Three methods for these compounds have been developed over the past decades:firstly, pyrolysis of a-azidoacetophenone phenylsulfonylhydrazones; secondly, non-metal catalyzed 1,3-dipolar cycloaddition of terminal alkyne with azides which have protecting groups after deprotection protecting groups; thirdly, transition metal catalyzed 1,3-dipolar cycloaddition of terminal alkyne and their derivatives with inorganic azide. However, these methods have many shortcomings and problems, such as harsh reaction conditions, the narrow scope of the substrates and so on. So developing a method to synthesize 4-aryl-NH-1,2,3-triazoles with a mild reaction conditions, a wide range of substrates has a strong scientific significance and practical value. In this paper, we reviewed the applications of the 1,2,3-triazole compounds and the synthetic methods of these compounds in recent years. Then, a novel and efficient access to 4-aryl-NH-1,2,3-triazoles through p-toluenesulfonic acid mediated 1,3-dipolar cycloaddition of nitroolefins with NaN3 has been achieved by reagent control under relatively mild conditions.