| Indole and aniline are two important types of organic nitrogen-containing compounds and their derivatives generally have broad medicinal activities and industrial value.In recent years,the derivatization of indoles and anilines has become one of the research hotspots of chemists.However,most of the methods reported in the literature have problems such as complicated operations and many metal wastes.Employing environmentally friendly oxidants is the key to overcome these deficiencies.Oxygen is reproducible,universal,non-toxic and harmless reagent,which is an ideal oxidant and oxygen supplement.According to the preliminary studies of out research group,the visible light photocatalytic and copper-catalyzed oxidative reactions with oxygen are feasible ways to achieve the oxidation and derivatization of indole and aniline compounds.This article focuses on the study of the oxidation of indole and aniline compounds with oxygen as the oxidant.In the first part,Ru(bpy)32+-catalyzed oxidative cleavage of indoles in the presence of oxygen was developed to generate o-aminobenzaldehyde derivatives.This strategy uses acetonitrile as solvent,oxygen as sole oxidant,and features several advantages such as wide scope of substrates,mild reaction conditions,etc.In the second part,oxygen-involved Ru(bpy)32+-catalyzed oxidative cyclization reaction of indoles was developed to synthesize 4-quinolinone derivatives.The reaction undergoes the C-C bond cleavage and subsequent Camps cyclization processes and has the advantages of mild reaction conditions and high atom economy.In the third part,the copper-catalyzed aerobic oxygenative cross dehydrogenative coupling of methyl ketones with para-C-H of primary anilines was developed to generate aniline-1,2-diketones.The advantages of this reaction include easy availability of raw materials,use of oxygen as oxidant,high tolerance of functional groups. |
