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毕业论文网 > 毕业论文 > 化学化工与生命科学类 > 生物工程 > 正文

光催化sp2C-H键官能团化反应的研究毕业论文

 2022-01-30 05:01  

论文总字数:36567字

摘 要

光催化是近十年来迅速发展的新技术,现在已经大范围地被应用到有机合成、天然降解、无机还原以及天然产物全合成等多个化学领域中,成为新时代全新技术的标志之一。现代可见光催化具有以下特点:(1)以可见光为能源,能量利用率高;(2)通过光催发光敏剂逸出电子参与氧化还原反应;(3)在温和的条件下开展自由基过程。

C-H功能化是一种高效直接地实现各种官能团化的方法,C-H键作为自然界储量巨大的有机化学键,直接功能活化应和了当前提倡绿色化学和原子经济的科研背景,具有重大的意义。本文以可见光的方式引发单电子循环,进入自由基过程从而实现C-H功能活化,相比传统的过渡金属催化方式条件简单且反应温和。

含氟化合物在药物化学和新材料合成学等领域有着广泛的应用潜力,其中三氟甲基基团对化合物的化学稳定性、亲油性和生物活性等都有显著的提升作用。三氟甲基化一直以来作为有机化学的研究热点,已经经历了长足的发展,包括自由基三氟甲基化在内的多种有效的合成方法已经被开发出来。可见光催化的出现则降低自由基三氟甲基化的引发条件,让这一高效的氟化方法更加简单普适。

本课题我们通过可见光诱导在微通道反应装置中将三氟甲基等官能团引入到底物1,7-烯炔分子中,一步反应实现了烯炔类化合物的C-H功能化和串联环化。实验中我们确定了400-450nm的蓝光对反应有卓越的效果。我们发现,这一光引发的体系可行高效,并且对多种底物适用性良好。

关键词:可见光催化 C-H功能化 三氟甲基化 1,7-烯炔

Abstract

Photocatalysis, as a newly developed technology in past ten years, has now been applied in several chemical fields including organic synthesis, natural degradation, inorganic reduction and total synthesis of natural products etc. It is certain that photocatalysis has become a brand new symbol of modern technology. Modern photocatalysis through visible light possesses several features: (1) utilize visible light as energy source, high energy utilization; (2) participate in redox cycles with electron initiated by light; (3) conduct a radical process in mild conditions.

C-H functional activation is an efficient and direct methodology to achieve virous functionalization of compounds. The functional activation method is meaningful. As C-H bonds widely existing in the natural world, the direct functionalization of C-H bonds meets the requirement of Green Chemistry and Atom Economy. In this paper, we initiated the single electron to participate in the radical process of C-H functional activation by using visible light.

Fluorine-containing compounds possess enormous potential in both pharmaceutical chemistry and functional material synthesis. Trifluoromethyl, as an important group in fluorinated molecules, which can increase the chemical stability, lipophilicity and biological activity of organic compounds literally. Trifluoromethylation has always been a hot issue in organic chemistry. Scientists have developed many effective ways of trifluoromethylation including the radical method. Recently, photocatalysis is proved able to be an easier way to the trigger condition of radical trifluoromethylation. This discovery makes radical fluorination easier and more universal.

In this project, we introduce trifluoromethyl functional groups into the substrate 1,7-enyne molecules through visible light induction in a microchannel reaction apparatus, and one-step realization of C-H functionalization and series cyclization of enyne compounds. Through experiments we have determined that the 400-450 nm blue light has an excellent effect on the reaction. We have found that this light-induced system is feasible and efficient, and it has good applicability to various substrates.

Keywords:Photocatalysis;C-H activation;Trifluoromethylation;1,7-enynes.

目 录

摘 要 I

Abstract i

第一章 绪论 3

1.1 引言 3

1.2 可见光催化的C-H键功能化 3

1.2.1 可见光催化的原理 3

1.2.2 可见光催化的活性C-H键功能化 7

1.2.3 可见光催化的应用前景 9

1.3 光催化的氟烷基化 10

1.3.1 有机氟化学的研究背景 10

1.3.2 光催化三氟甲基化的研究背景及意义 11

1.3.3 光催化Sp2C-H键的三氟甲基化的研究 11

1.4 本文的研究内容和意义 14

第二章 光催化的1,7-烯炔双官能团化 17

2.1 实验部分 17

2.1.1 光催化1,7-烯炔的三氟甲基化与卤代反应 17

2.1.2 本章小结 27

第三章 结论与展望 29

参考文献 30

附 录 37

致 谢 42

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