Conversion Of Methyl Arenes And Benzyl Bromides To Nitriles By Copper-Catalyzed Oxidation

As a kind of important organic compounds,aromatic nitriles exists in natural products,medicine,pesticides and materials.According to the chemical reactivity of cyano group,the synthesis of aromatic nitriles has always been a hot topic in organic chemisty research.A novel method of synthesizing a series of aromatic nitriles from methyl arenes and benzyl bromides was systematically studied.The main work of this paper contains the following three parts:In the first chapter,the research status of aromatic nitrile was discussed.The starting materials for the synthesis of aromatic nitriles were summarized,including benzyl halides,benzylamine,aryl ethylene oxide,benzyl alcohol,benzyl azide,benzoic acid,styrene and toluene.The effects of different nitrogen sources,catalysts,oxidants and solvents on the reactions were discussed.And the mechanism of this reaction systems was described.All of these tendencies had their impact on the choice of materials,oxidants and nitrogen sources to be cheap,mild,easy to obtain,green and environmentally friendly.Based on systematically summarizing the existing reaction systems,our assumption and reaction design were carried out.In the second chapter,the preparation of aromatic nitriles from benzyl bromides was studied.At present,there are some problems with benzyl bromides to prepare aromatic nitriles in reported literature,such as using complicacy oxidant,unstable nitrogen source and difficult to obtain,which limited the further application of these reactions.CuI is widely used in the preparation of aromatic nitriles as a common catalyst.In this study,CuI-catalyzed oxidation of benzyl bromides to nitriles was reported.The optimized reaction conditions（benzyl bromides,5 mol%CuI,1.5 equiv.（NH₄）₂CO₃,3.0 equiv.TBHP）were obtained by optimized nitrogen sources,catalysts,oxidants and solvents.Under the optimized conditions,a broad of substrates could be oxidized to target products in high selectivity,and showed good functional group tolerance.Then the scale-up reaction was studied.The possible reaction mechanism was discussed based on the related reports and experimental results.Chapter 3 developed the oxidative nitrification of methyl aromatics by CuI and TBHP oxidation system.Through the screening of conditions,we found that aq.NH₃as a nitrogen source could highly improve yield.Besides,the two-phase reaction could have a good yield even without solvents.The advantages of this method were mild reaction conditions,simple operation and easy availability of materials.It performed well in laboratory scale-up reaction.Finally,the applications of CuI and TBHP oxidation systems in other toluene derivatives were expanded.