Rh(?)-catalyzed C-H Activation And Its Application In The Synthesis Of Heterocyclic Compounds

The direct functionalization of carbon hydrogen bonds has greatly enriched the content of traditional organic synthetic methodology,which represents a simple and effective method for inverse synthetic analysis for complex target molecules and a promising strategy for expediting the synthesis of sophisticated chemical architectures.Therefore,transition metal catalyzed direct C-H functionalization has been a central problem of the methodology in recent years.This thesis mainly focuses on the reactions of new directing groups in Rh-catalyzed C-H functionalization and the application of the syntheis protocol to the syntheis of heterocyclic structure.The main contents include:In the first chapter,we simply introduce the tcurrent development situation of Rh-catalyzed C-H bond activation.In the second chapter,we report a research about Rh-catalyzed N-Nitroso-Directed C-H Addition to 2-Oxoacetate reaction.The utility of N-nitroso group has enabled to heighten reactivity,such as mild reaction condition,high yield and diversity of products.Studying on the mechanism of synthesis:Single crystal diffraction experiment of five membered ring structure,kinetic isotope effect experiments,competition experiment,as well as the necessity of directing group etc.The mechanism of the circulation way possible:C-H bond activation reaction is the rate determining step;a kind of reactive five-membered rhodacycle structure is the key intermediates in the catalytic cycleIn the third chapter,we report a research about Rh-catalyzed internal oxidative olefination of C-H bond on arene with directing group N-OH.The reaction has the several advantages such as mild conditions,high yields,broad substrate scope and atom economy,and which unusually uses hydroxyl as both directing group and internal oxidation group.In the fourth chapter,we report a research about application of Rh-catalyzed N-Nitroso-Directed C-H Addition to 2-Oxoacetate reaction for heterocyclic synthesis.In exploring how to remove the directing group,we find the reaction conditions of the synthesis of oxindole.Hydroxyl carboxylic acid ester can be transformed the indazole structure under alkaline conditions,and its application to the synthesis of three membered fused ring structure.the reaction product indole?Indazoles?tricyclic fused ring make full use of directing groups.In a series of reactions,nitroso as functional groups,not only plays a role of directing groups,can also be timely to take off or removed under certain conditions.