论文总字数：24964字

摘 要

2-位取代的芳基苯并噁唑以其优秀的生物活性和良好的抗菌消炎功效以及荧光特性，逐步进入了有机化学家的视野。近年来，世界各国的有机化学家们已经尽最大努力来开发合成2-取代苯并唑的有前途的策略。其中应用较为广泛的合成方法主要以芳香胺的氧化环化与苯并恶唑类化合物的芳基化两种方法为主。在传统的2-取代苯并唑的合成中，常用重金属如钯和铜作为催化剂，不仅不利于降低成本，同时在污染和安全上也存在较大隐患。因此，虽然2-芳基苯并噁唑的合成方法还有很多，但是探索一种由简单易得的起始原料与低污染催化剂合成2-取代的苯并恶唑的新方案仍然迫切。

硫在有机合成中被广泛用作化学计量试剂（硫化剂、氧化剂或还原剂），但它作为催化剂的作用尚未得到充分的探讨，硫在铁粉或盐的存在下被用作催化剂，用于芳香硝基化合物的氧化还原缩合，Fe/S氧化还原体系被认为是氧化还原催化蛋白活性中心中涉及电子转移的最有趣的催化剂之一。但催化硫在制备2-芳基苯并唑中的应用仍然很少。

基于此，本文推断以邻硝基苯酚为底物，经Fe/S催化氧化还原体系制备2-芳基取代苯并噁唑是一种有较广阔前景的新型合成方式。本实验以模型底物2-硝基苯酚与二苄基二硫进行条件优化，进而进行底物适用性研究，包括取代基的种类对收率等的影响。并且取得了令人兴奋的收获，该反应所得2-芳基苯并噁唑的收率普遍良好。

关键词：2-芳基苯并噁唑 2-硝基苯酚 Fe/S氧化还原体系 氧化还原缩合

Preparation of 2-arylbenzoxazole by iron/sulfur catalytic redox condensation reaction

Abstract

2-Substituted arylbenzoxazole has gradually entered the field of vision of organic chemists with its excellent biological activities, good antibacterial and anti-inflammatory effects and fluorescent properties. In recent years, organic chemists from all over the world have done their best to develop promising strategies for the synthesis of 2-substituted benzoxazoles. Among them, the widely used synthetic methods are mainly oxidized cyclization of aromatic amines and arylation of benzoxazole compounds. In the traditional synthesis of 2-substituted benzoxazoles, heavy metals such as palladium and copper are commonly used as catalysts, which is not only not conducive to cost reduction, but also has great hidden dangers in pollution and safety. Therefore, there are many synthetic methods for 2-arylbenzoxazole, but it is still urgent to explore a new method for synthesizing 2-substituted benzoxazoles from simple and easily available starting materials and low-pollution catalysts.

Despite extensive use of sulfur in organic synthesis as a stoichiometric reagent (sulfurating, oxidizing or reducing agent), its role as catalyst was underexplored. Sulfur was used as a catalyst in the presence of iron powder or salts for redox condensation of aromatic nitro compounds. The Fe/S redox system is considered among the most interesting catalysts involving electron transfer in active centers of redox catalytic proteins. However, catalytic sulfur is still rarely used in the preparation of 2-arylbenzoxazole.

Based on this, this paper concludes that the preparation of 2-aryl-substituted benzoxazole by Fe/S catalytic redox system using 2-nitrophenol as a substrate is a new and promising synthesis method. In this experiment, the model substrates 2-nitrophenol and dibenzyl disulfide were used to optimize the conditions, and then the suitability of the substrate was studied, including the effect of the type of substituent on yield. And an exciting result has been achieved. The yield of

2-arylbenzoxazole obtained by this reaction is generally good.

Key words：2-Arylbenzoxazole; 2-Nitrophenol; Fe/S； Redox condensation

目 录

摘 要 I

Abstract II

第一章 文献综述 1

1.1 引言 1

1.2 2-芳基苯并噁唑化合物简介 2

1.2.1 2-芳基苯并噁唑类化合物性质及应用 2

1.2.2 2-芳基苯并噁唑类化合物合成的研究进展 3

1.3 课题研究内容及意义 5

第二章 实验部分 7

2.1 实验内容 7

2.2 实验仪器及试剂 7

2.2.1 实验仪器 7

2.2.2 实验试剂 7

2.3 实验步骤 8

2.3.1 反应条件优化 8

2.3.2 底物拓展 8

第三章 结果与讨论 9

3.1 反应条件优化结果 9

3.2 底物拓展结果 11

3.3 化合物结构表征 13

第四章 总结与展望 19

参考文献 20

附 录 23

第一章 文献综述

1.1 引言

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