The Syudy Of Aerobic Oxidation Of Nitro-substituted Alkylarenees To Aromatic Alcohols/Aromatic Aldehydes/Aromatic Acids

This thesis mainly focused on the study of the aerobic oxidation of the nitro-substituted alkylarenes to aromatic alcohols,aromatic aldehydes or aromatic acids using O₂ as green oxidant.In the first part,the study focused on the aerobic oxidation of o-nitrotoluene to o-nitrobenzaldehyde?ONBD?using iron-metalloporphyrins as biomimetic catalysts.Various reaction conditions were optimized,such as the types of catalysts,reaction time,reaction temperature,sodium hydroxide concentration,substrate concentration,and oxygen pressure.When the concentration of the o-nitrotoluene is 0.1 mol/L,the isolated yield of 47%could be achieved for the desired o-nitrobbenzaldehyde using T?o-Cl?PPFeCl as a catalyst in methanol at 40 ^oC.In the second part,the study focused on the metal-free aerobic oxidation of nitro-substituted alkylarenes to aromatic acids or benzyl alcohols promoted by NaOH.This sustainable system uses O₂ as clean oxidant in a cheap and green NaOH/EtOH mixture with high chemoselectivities.The position and type of substituent critically affect the products.The methyl groups on the ortho or para positions of the nitro group can be oxidized selectively to yield the corresponding carboxylic acids with isolated yield of up to 95%,and the substrate conversion of>99%.If the nitro-substituted alkylarenes with a linear alkyl group on the ortho position of the nitro group,or a branched alkylgroup on the para position of the nitro group,sole product benzyl alcohols were obtained,and the conversion and isolated yield could be up to 97%and 87%respectively.In addition,this sustainable protocol enabled gram-scale preparation of carboxylic acid and benzyl alcohol derivatives.Finally,the reactions can be conducted in a pressure reactor,which can conserve oxygen and prevent solvent loss,and also be conducive to environmental protection.