Synthesis Of Indolinones/Isoindolinones Based On C–H Activation And Functionalizations

Indolinones/isoindolinones and their derivatives are important nitrogen-containing heterocyclic compounds,which are widely existed in natural compounds and drugs.Inspired by their unique biological activity and consequent potential application,indoleones/isoindolinones have gained increasing attention of organic chemists.In recent years,a variety of methods of synthetic indolones/isoindolinones have been developed.Therefore,the development of methods for the synthesis of indolones and isoindolones has important research value and significance,which is consistent with the concept of green chemistry.In this paper,we focus on the synthesis of oxindoles and isoindolinones.The specific work is as follows:(1)A visible-light-induced and iron-catalyzed methylation of N-arylacrylamides by dimethyl sulphoxide(DMSO)leading to 3-ethyl-3-methyl indolin-2-ones under mild conditions.In this work,we have achieved an economical and convenient protocol for the preparation of various 3-ethyl-3-methyl oxindoles by white LED(3 W)promoted and iron-catalyzed difunctionalization of N-arylacrylamides through a free radicaltriggered cascade process.The reaction was driven by visible-light in the absence of photocatalyst and was provided a novel protocol to regioselectively synthesize substituted oxindoles under mild conditions.(2)The method has achieved an efficient protocol for the preparation of various isoindolinones by novel N,O-bidentate-oriented groups and ethyl acrylate through palladium-catalyzed C–H activation.In this reaction,the N-(2-acetylphenyl)benzamide and ethyl acrylate were used as raw materials,the transformation proceeded smoothly via ortho-C–H bond activation and further cyclized to isoindolinones in good regio-selectivity under mild reaction conditions.The method expressed high levels of functional group tolerance and synthesized a series of substituted isoindolinones.