Methodology Study Of Nitrogen-containing Heterocyclic Compounds Synthesis From "Azide Compounds" Using Tandem Reaction

Nitrogen-containing heterocyclic compounds are widely used in biology, medicine, materials and other areas for their special structures and properties. A large proportion of clinical drugs contain nitro-heterocyclic structures. With the development of science and technology, separation and extraction of nitro-heterocyclic compounds from nature could not meet the scientists’ need any more. Hence, it is meaningful to design and explore new and facile synthetic methodology of nitro-heterocyclic compounds which possess special function and application. Also, the construction of nitro-heterocyclic libraries with these new methodologies could contribute to the discovery of new leading compounds. This article reviews the application of vinyl azides in the synthesis of nitro-heterocyclic derivatives in detail. And two new approaches to the nitro-heterocyclic derivatives from azide compound using tandem reactions are introduced.Vinyl azide with both electrophilic and nucleophilic properties is a new type of sypthon. It is receiving much more attention by chemists in recent years. And various ways to nitro-heterocyclic compounds have been achieved. However, it is still a challenge to prepare nitro-heterocyclic compounds. In this article, we provide an alternative approach to the pyrazoles from vinyl azide, aryl aldehyde and p-toluenesulfonohydrazide using a "one-pot" three component strategy and a possible mechanism is proposed.21 compounds are synthesized in yield 54% to 92%. This methodology is concise, efficient and the starting materials are also easily available.Another methodology to the pyridine derivatives is achieved through [2+2+2] cycloadition of keto azides and alkynes in contrast to previous work (click reaction to triazole derivatives).19 new compounds are synthesized in yield 32% to 81%. According the experiment result, we postulate that keto azides behave in two manners. One acts as a nucleophile and another is attacked after the cleavage of nitrogen. This methodology contains following advantages:mild reaction condition, no need for metals and capability of various function groups.