从廉价且丰富的原料中构建高合成价值的产品非常重要，芳基碘化物是合成功能分子的重要组成部分，因此从化学原料中合成芳基碘化物的有效方法备受追捧。脱羧卤化反应，或称卤代脱羧反应，是合成普遍存在的有机卤化物的关键方法之一。该方法基于羧酸转化为相应的有机卤化物，通过选择性切割分子骨架和羧基之间的碳-碳键并释放二氧化碳。

本论文提出了一种低成本的脱羧碘化反应。该反应使用容易获得的芳甲酸系列化合物作为原料，并使用价格低廉易得的脱羧碘代试剂氯化碘。我们对该反应底物进行了拓展，发现常见富电子芳环上的甲酸基团更适合于该反应，包括芳胺（含氮杂芳胺）2位、4位、含有两个甲氧基的芳环上富电子位置以及吲哚3位上甲酸。此外，该条件可在水溶液中进行，这使一些在有机溶剂中溶解性差的底物发生该反应成为可能，大大拓展了该反应的应用范围。避免或减少有机溶剂的使用也具有很大的环境价值，是一种绿色合成方法。

机理研究表明，该反应是通过正离子过渡态实现脱羧卤代，不是通过自由基机制进行的，这与经典的Hunsdiecker-type脱羧卤化反应相反。此外，与现有的脱羧氧化偶联方法相比，因为避免了使用化学计量过渡金属，该方法具有明显的优势。这种低成本、高效率、易操作的方法可以用于合成各种重要的芳基碘化物，并且可以在大规模生产中使用。

Constructing high-value products from cheap and abundant raw materials is crucial. Aryl iodides are an important component in the synthesis of functional molecules, and therefore, an effective method for synthesizing aryl iodides from chemical feedstocks is highly sought after. The decarboxylative halogenation reaction, also known as the halogenation-decarboxylation reaction, is one of the key methods for synthesizing organic halides that are widely used. This method involves converting carboxylic acids to organic halides by selectively cleaving the carbon-carbon bond between the carboxyl group and the molecule's backbone, releasing carbon dioxide in the process.

This thesis proposes a low-cost decarboxylative iodination reaction. The reaction uses readily available benzoic acid compounds as starting materials and inexpensive decarboxylative iodine reagents such as iodine chloride. We have expanded the scope of this reaction and found that the formyl group on common electron-rich aromatic rings is more suitable for this reaction, including 2- and 4-aminophenyl (nitrogen-containing heteroaryl) groups, electron-rich positions on aromatic rings with two methoxy groups, and 3-indolecarboxylic acid. In addition, this reaction can be carried out in an aqueous solution, making it possible to use substrates that are poorly soluble in organic solvents and greatly expanding the application range of this reaction. Avoiding or reducing the use of organic solvents also has significant environmental value and is a green synthesis method.

Mechanistic studies suggest that this reaction achieves decarboxylative halogenation through a cationic transition state, rather than a radical mechanism, which is in contrast to the classical Hunsdiecker-type decarboxylative halogenations. In addition, compared with existing decarboxylative oxidative coupling methods, this method has significant advantages because it avoids the use of stoichiometric transition metals. This low-cost, efficient, and easy-to-operate method can be used to synthesize various important aryl iodides and can be used in large-scale production.