Study On Rh(?) Catalyzed Activation Of C-H Bond To Synthesize Oxygen-Containing Heterocycles

Dibenzopyranone is a coumarin analogue,which widely exists in a variety of natural products and has important physiological activities.So far,the synthesis of these compounds has been widely studied.In this paper,a new method for the synthesis of polysubstituted dibenzo[b,d]pyran-6-ones by Rhodium(?)catalyzed C-H bond activated series cyclization is proposed.This method has the advantages of simple operation,high reaction efficiency,high atom and step economy,and has experienced unprecedented experience in the reaction process ?-C elimination mechanism.The thesis is divided into three chapters.The first chapter introduces the strategy of transition-metal-catalyzed C-H bond activation to synthesize oxygen-containing heterocycles.Among them,dibenzopyrones have important biological activities as important oxygen-containing heterocycles.This chapter reviews the synthesis methods of dibenzopyrones in recent years.In the second chapter,we put forward the basis for the topic selection of this paper,mainly introducing the synthesis of nitrogen-containing heterocycles with oxime as the guiding group under the catalysis of Rhodium(?),while this topic is the synthesis of oxygen-containing heterocycles with the same guiding group and catalyst.In the third chapter,the synthesis of dibenzo[b,d]pyran-6-ones from O-acetylacetophenone oxime and p-benzoquinone catalyzed by Rhodium(?)is introduced in detail,including the optimization of reaction conditions,the expansion of reaction range and the exploration of reaction mechanism,etc.