Selective Oxidation Of Heterobenzyl Alcohol Catalyzed By F₂₀TPPFeCl/TEMPO

As a basic organic compound,（hetero）aromatic aldehydes/ketones are widely used in natural active substances and in drug synthesis.At present,many methods and systems have been developed to synthesize（hetero）aromatic aldehydes/ketones,and the method of selectively oxidizing（hetero）benzyl alcohol to obtain（hetero）aromatic aldehydes/ketones has attracted wide attention in this field because of its simple and efficient characteristics,So far,many oxidation systems for（hetero）benzyl alcohol have been developed.These systems are mainly divided into two types:transition metal catalytic systems and non-transition metal catalytic systems.In addition,photocatalysis,electrocatalysis and other systems are also a research hotspot in recent years.The research team hopes to develop a reaction system that can rapidly and efficiently selectively oxidize（heterobenzyl）alcohol under mild conditions.First,iron,as a key component of hemoglobin,is abundant in the human body and is a transition metal element with high biological affinity.Biomimetic catalysts such as metalloporphyrins,which mimic cytochrome P450,also have high biological affinity and exhibit coloration in catalytic oxidation reactions.Therefore,we hope to use 5,10,15,20-tetra（pentafluoroaryl）iron chloride porphyrin(F₂₀TPPFe Cl)as a catalyst,Combined with the work that has been carried out in the laboratory,the selective oxidation of（hetero）benzyl alcohol was studied.In this thesis,two main works have been done:Firstly,a selective catalytic oxidation system for（hetero）benzyl alcohol has been developed.The selective oxidation of heterocyclic benzyl alcohol was studied using this system.Thirdly,the selective oxidation of aryl alkynyl alcohol was studied using this system,and the possible reaction mechanism was proposed.In the first chapter,a selective oxidation system of heterocyclic benzyl alcohol using 5,10,15,20-tetra（pentafluoroaryl）ferric chloride porphyrin(F₂₀TPPFe Cl)as catalyst was first explored.Then,using 3-pyridine methanol as the model substrate,the selective oxidation of 3-pyridine methanol was successfully achieved by optimizing the conditions,and 3-pyridine formaldehyde was obtained with a separation yield of87%.The optimum reaction conditions are as follows:the amount of F₂₀TPPFe Cl is 0.3 mol%,the amount of the cocatalyst TEMPO is 8 mol%,tert-butyl hydrogen peroxide is selected as the oxidant,and the amount of the oxidant is 2 equiv,acetonitrile is selected as the solvent,and the reaction is conducted at 35℃.Under the optimal reaction conditions,22 heterocyclic benzyl alcohols were expanded to obtain 12 pyridine formaldehyde products（yield 64-88%）,6 quinoline formaldehyde products（yield 63-70%）,2 indole formaldehyde products（yield 32-37%）,1 imidazole（40%）,and 1 thiazole（50%）heterocyclic formaldehyde substrate.Moreover,a good yield（75%）of the model substrate 3-pyridine methanol was obtained through a gram scale up experiment,indicating that the system has a good prospect in practical applications.In Chapter 2,the selective oxidation of aryl alkynyl alcohol was studied.When 1-aryl-2-propargy-1-alcohol was used as a model substrate and the reaction was carried out under the optimal reaction conditions optimized in Chapter 1,an excellent yield of 96%was obtained,indicating that the reaction system had a good substrate application range.Therefore,the reaction conditions for aryl alkynyl alcohols were not further screened,but the best reaction conditions in Chapter 1 were directly utilized.After that,we expanded the development of aryl alkynyl alcohol substrates.We first synthesized a total of 40 aryl alkynyl alcohol substrates,and obtained 17 aryl alkynyl acetone products（yield:85-97%）.We obtained 22 aryl alkynyl butanone products（yield:72-98%）.We used 1-aryl-2-propane-1-ol as a model substrate for a gram scale reaction to obtain a yield of 85%.The possible reaction mechanism was proposed.A total of 100 compounds were synthesized and 61 products were obtained,including 11 new compounds.The results show that the system has good substrate applicability,mild reaction conditions,green and efficient catalyst,and has good application prospects...