Study On The Selective C-H Bond Activation Of Aryl Compounds And Quinone Derivatives

Transition metal-catalyzed C-H activation is an important field of organic synthesis in recent years.It is of great significance to study synthetic methods of quinone compounds and their derivatives which have various potential medicinal values.In this paper,we mainly study the transition metal-catalyzed direct C-H activation of aryl compounds and the C-H activation of quinone derivatives.These researches have contributed to the progress of the selective hydrocarbon activation of aryl compounds to some extent,and also provided new ideas for the synthesis of some intermediates of aryl quinones and sulfur-containing aryl quinone derivatives.The main contents are as follows:1.Study on the rhodium-catalyzed alkenylation reactions via amide-directed C-H activation[Cp*RhCl₂]₂-catalyzed selective C-H activation of diaryl-substituted anilides by the use of the silver carbonate was developed.We obtained an N-aryl ring product under the rhodium catalyst with the help of silver trifluoromethanesulfonate,whereas the C-aryl ring product was obtained in the absence of a non-coordinating anion.The olefination of amides has good chemical and regioselectivities and functional group tolerance.Mechanistic studies and theoretical calculatios proved the non-coordinating anion plays a key role in this reaction.A possible reaction pathway for this transformation was proposed.2.Study on the rhodium-catalyzed amidation reactions via amide-directed C-H activationA novel method for the amide amidation reaction through rhodium-catalyzed selective C-H activation with isocyanates was developed.The reaction conditions are simple with good to excellent yields.It is suitable for all kinds of alkyl isocyanates,and even aryl isocyanates can participate in the reaction.This method provides a practical and efficient method for the synthesis of asymmetric bisamides.3.Study on the rhodium-catalyzed alkenylation reactions via triazole-directed C-H activationA pyridylbenzotriazole compound which was used to study the competitive coupling reaction with acrylates was designed.The reaction was carried out with [Cp*RhCl₂]₂ as catalyst,copper acetate as oxidant and silver hexafluoroantimonate as additive.It was found that the C-H activation occurs only on the pyridine ring which means that triazole was more conductive than pyridine in this kind of compounds.In addition,a variety of phenylbenzotriazole compounds with electron donating or withdrawing groups can gain corresponding products with good to excellent yields.And we also made a series of mechanisms to explore the reaction experiment.4.Study on the copper-catalyzed coupling reaction of benzoquinone with benzenesulfonyl chloride compounds to synthesis thio-aryl-quinone derivativesBenzene sulfonyl chlorides were used as the coupling reagents to synthesis sulfur-containing aryl quinone derivatives for the first time.Only sulfur-containing aryl quinone derivatives were generated without the formation of other sulfonylquinone derivatives under the conditions of cheap copper catalyst and reducing agent-triphenyl phosphine.Both mono-and di-substituted benzenesulfonyl chlorides give the desired products in a medium to good yield.This method provides a new alternative for the synthesis of sulfur-containing aryl quinone derivatives.5 Study on the palladium-catalyzed naphthoquinone cross-coupling with halogenated phenol and haloalkane compounds to form aryl quinone derivativesWe developed a novel synthetic method of aryl quinone derivatives by cross-coupling of iodophenol and haloalkane with naphthoquinone in one pot.Haloalkane is both a reactant and a solvent in this reaction.Compared with the previous method of synthesizing aryl quinone derivatives,this method has the prominent advantages of simple operation,mild condition,green and economy.