Study On The Domino Cyclization Reaction Of Isocyanide And O-Alkynyl Azide Catalyzed By Rhodium

The structures of indole[2,3-b]quinoline,dibenzonaphthyridine and dibenzonaphthyridone are a kind of promising molecular framework in organic chemistry and pharmaceutical chemistry.The core structures are widely present in various natural products and biological activities compounds.and has a variety of important physiological and medicinal properties.Therefore,the exploration of the structure and properties of them has attracted wide attention from chemists.Among the various synthetic methods that have been reported,the transition metal-catalyzed cyclization strategy has become one of the most effective methods for the synthesis of these three types of compounds.Therefore,the development of a new method for the synthesis of these compounds from non-fused ring precursors is very promising.In organic chemistry,isocyanide compounds are an important class of synthons,which are of great significance in the study of synthetic methods of nitrogen-containing heterocycles,and are widely used in the fields of organic synthesis,drug synthesis,and total synthesis of natural products.In addition,azide,as one of the important nitrogen sources,has shown increasing utility in the synthesis of nitrogen-containing compounds.In the azide family,o-alkynyl azide has been widely used in the synthesis of heterocyclic rings due to the basic structural features of both alkyne and azido functional groups.In the field of research on the reaction of isocyanide and azide,transition metal-catalyzed coupling and cyclization of isocyanide and azide compounds has been one of the most common methods for the synthesis of nitrogen-containing heterocycles.There are few studies on the coupling and cyclization reaction of nitrogen compounds and isocyanide compounds.Therefore,it is worthwhile to develop a new type of coupling and cyclization reaction between o-alkynyl azides and isocyanide compounds to synthesize other important nitrogen-containing heterocycles.In this paper,rhodium was used as a catalyst to successfully realize the novel coupling and cyclization reaction of aryl isonitrile with various o-alkynyl azide derivatives.This reaction used the coupling intermediate carbodiimide formed by aryl isonitrile and o-alkynyl azide as the key intermediate.Through the continuous intermolecular coupling and intramolecular cyclization reaction process,indole[2,3-b]quinoline,dibenzonaphthyridine and dibenzonaphthyridone compounds were constructed in one step.The experimental results not only provide a simple and effective method for constructing indole[2,3-b]quinoline,dibenzonaphthyridine and dibenzonaphthyridone derivatives,but also have laid a solid foundation of aryl isocyanide coupling and cyclization reaction with alkynyl azide in the synthesis of other nitrogen-containing heterocyclic compounds.