Palladium-Catalyzed Hydroxyl-Directed C-H Activation /Dearomatization Reaction

Transition-metal-catalyzed C-H activation by directing groups is an convenient ? efficient means for building target compounds.Phenolic compounds are a kind of common aromatic compound.In recent years,the organic chemists are interested in disrupting the stable aromatic system to obtain more important organic synthesis fragments.This dissertation is aim to explore a more efficient and practical chemical conversion method to break down the aromatic system of aromatic compounds based on the C-H activation with the help of directing groups.The first chapter focuses on the following two aspects:(1)the palladium-catalyzed hydroxyl-directed C-H activation which including phenolic hydroxyl group and alcoholic hydroxyl group.(2)the reseach progress of palladium-catalyzed intermolecular and intramolecular dearomatization of phenols.The second chapter introduces Pd(?)-catalyzed C-H activation and dearomatization of ?-naphthol.The reaction successfully synthesized a series of important spirocyclic framework through the activation of C-H by the directed hydroxyl group,the insertion of alkynes and the dearomatization of naphthols.The yield of reaction could be up to 95%.In the third chapter,the commonly used spirofluorene backbone fragments in organic electroluminescent materials were successfully synthesized by palladium-catalyzed hydroxyl-directed C-H activation and dearomatization strategy.This reaction is achieved through oxidation of carbon halogen bonds,/ C-H activation / dearomatization reaction.The yield of reaction could be up to 88%,and the KIE experiment suggests that the C-H bond cleavage is most likely involved in the rate-limiting step.