Synthesis Of Heterocycles Via Gold-catalyzed Intramolecular Cyclization Of (Azido)Ynamides

Ynamine is a class of organic compounds that alkynes are directly connected to amino compounds.It is also an important class of compounds following the enamine and being widely used in organic synthesis.Ynamine has cheap,easy to synthesize,therefore, the research of ynamine chemistry, especially for the properties of ynamides has been one of the focuses in chemical research.We will introduce a novel method for the construction of indole/isoquinoline skeletons achieved from ynamide substrates through a gold-catalyzed tandem intramolecular alkyne amination/X-H insertion in this thesis.The application of indole compounds was widely used in pesticide, food, medicine, feed and kinds of additives and it also has great value in daily life. Since the indole compounds were discovered, the synthesis of indole rings were always the constant pursuit of innovation, there have been many synthetic routes in the classic synthetic method in the industry,such as fischer reaction, L-B reaction?Madelung reaction?Bischer reaction and so on. Although numerous strategies for indole synthesis have been developed and used for industrial applications, access to the [1,4]oxazino[3,2-b]indoles or 1H-pyrazino [2,3-b]indoles remains scarce. Therefore, it is necessary to develop the new strategy for the synthesis of these structures, especially for the complex heterocyclic structures, espscially directly synthesized from cheap and readily available substrates. Due to the diversity of the formation of functional groups, good carbene it has become the most important areas of gold catalysis, we developed a novel method for the construction of these indole skeletons achieved from ynamide substrate 1 through a gold-catalyzed tandem intramolecular alkyne amination/X-H insertion.This new method also has advantages such as excellent yields,mild reaction conditions and so on.Isoquinoline compounds in development of new pharmaceuticals, pesticides and dyes have been showing more active state. Quinolines as important fine chemical raw materials, many of quinoline compounds are important pharmaceutical intermediates and isoquinoline derivatives also as important alkaloids are being widely used. Great progress has been made in the process of synthesis of isoquinoline s, ischler-Napieralski reaction Pictet-Spengler reaction Pomeranz-Fritsc reaction and so on.Despite these significant achievements, large number of cyclizations have to be quenched by an electrophile, that is, the position 4 of the produced isoquinoline is limited to a hydrogen or halogen. Therefore, the exploration of novel and general methods for such a cyclization is highly desirable. Here we introduce such a gold-catalyzed tandem alkyne amination/intramolecular O-H insertion, which provides ready access to valuable [1,4]oxazino[3,2-c]isoquinolines in generally good to excellent yields. This new method also has many advantages such as high functional-group tolerance,mild reaction conditions and so on.