碘促进的环己烯酮芳构化策略合成酚与芳香伯胺

发布时间：2018-07-29 13:16

【摘要】：分子碘能促进多种官能团转化,是很多有机反应的高效催化剂。本文包括两部分:碘催化氧化环己烯酮芳构化合成间位取代酚和碘促进的Semmler-Wolff反应。酚类化合物是合成生物活性分子、聚合物和其他精细化学品的重要前体。利用芳香取代化学,合成含邻、对位取代基的酚比较容易实现,但是,芳香取代的定位效应使得间位取代酚的合成具有一定的挑战性。由此,我们探索了以环己烯酮作为底物合成间位取代酚的方法。反应以催化量的分子碘作为直接氧化剂引发,二甲基亚砜用作终端氧化剂。方法避免了使用重金属催化剂和昂贵的试剂,原料易得,底物适用范围广,氧化条件温和,产物未见过度氧化。实现了在温和条件下用廉价商业化学品有效构建间位取代的苯酚衍生物。芳胺是另一类重要的有机合成中间体,简单的芳香伯胺一般可以用芳香硝基化合物还原得到,但间位取代的芳基伯胺合成则需要冗长的实验步骤。由此,我们探索了用碘促进的Semmler-Wolff反应,将环己烯酮肟一步转化成间位取代的芳香伯胺。与传统的Semmler-Wolff反应相比,本方法既不需要使用强的布朗斯特酸和苛刻的反应条件,并避免了肟的预先衍生和产物的脱保护步骤,而且,不需要使用贵金属催化剂,反应条件温和,操作简便,有一定的实用价值。
[Abstract]:Molecular iodine can promote the conversion of many functional groups and is a high efficient catalyst for many organic reactions. This paper consists of two parts: iodine catalyzed oxidation of cyclohexenone aromatization to m-substituted phenol and iodine-promoted Semmler-Wolff reaction. Phenolic compounds are important precursors for the synthesis of bioactive molecules, polymers and other fine chemicals. The synthesis of phenols containing ortho and para-substituents is easy to achieve by using aromatic substitution chemistry. However, the localization effect of aromatic substitutions makes the synthesis of m-substituted phenols challenging to some extent. Therefore, the synthesis of m-substituted phenols using cyclohexenone as substrate has been explored. The reaction was initiated by catalytic amount of molecular iodine as direct oxidant, and dimethyl sulfoxide was used as terminal oxidant. The method avoids the use of heavy metal catalysts and expensive reagents, the raw materials are easy to obtain, the substrate is suitable for a wide range, the oxidation conditions are mild, and the products are not overoxidized. The synthesis of substituted phenol derivatives with cheap commercial chemicals under mild conditions has been achieved. Aromatic amines are another important intermediate in organic synthesis. Simple aromatic primary amines can be reduced by aromatic nitro compounds, but the synthesis of m-substituted aryl primary amines requires lengthy experimental steps. Therefore, we have explored the Semmler-Wolff reaction promoted by iodine and transformed cyclohexene ketone oxime into substituted aromatic primary amines in one step. Compared with the traditional Semmler-Wolff reaction, this method does not need to use strong brownstearic acid and harsh reaction conditions, and avoids the pre-derivation of oxime and the de-protection step of the product. Moreover, the reaction conditions are mild without the use of precious metal catalyst. The operation is simple and has certain practical value.
【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O621.3

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