CN-122010798-A - Alkali-free recyclable decarboxylation reaction method based on photocatalysis of water-soluble uranyl salt

Abstract

The invention provides an alkali-free recyclable decarboxylation reaction method based on water-soluble uranyl salt photocatalysis, and belongs to the technical field of organic synthesis. The decarboxylation reaction method comprises the steps of mixing a carboxylic acid compound, an electron-deficient olefin compound and a water-soluble uranyl salt under the alkali-free condition, adding a reaction medium containing water to obtain a mixture, and then irradiating the mixture with visible light to carry out decarboxylation addition reaction on the carboxylic acid compound. The decarboxylation reaction method has the advantages of mild condition, wide substrate application range and good functional group tolerance. The invention utilizes the water solubility of uranyl salt, and can realize the recovery and repeated recycling of the catalyst through simple phase separation after the reaction, thereby obviously reducing the cost and the environmental impact. Moreover, the invention provides a new green, economical and sustainable strategy for decarboxylation functionalization of carboxylic acids.

Inventors

• LEI TAO
• ZHANG GUANGZHI
• YANG WEITING

Assignees

• 海南大学

Dates

Publication Date

20260512

Application Date

20260130

Claims (9)

1. 1. An alkali-free recyclable decarboxylation reaction method based on water-soluble uranyl salt photocatalysis is characterized by comprising the following steps: Under the alkali-free condition, a carboxylic acid compound, an electron-deficient olefin compound and a water-soluble uranyl salt are mixed, a reaction medium containing water is added to obtain a mixture, and then the mixture is irradiated with visible light to carry out decarboxylation addition reaction on the carboxylic acid compound.
2. 2. The method for the photocatalytic alkali-free recyclable decarboxylation reaction based on water-soluble uranyl salts according to claim 1, wherein the carboxylic acid compound is any one of aliphatic carboxylic acid, aryloxyacetic acid, amino acid derivative and phenylacetic acid compound.
3. 3. The method for the photocatalytic alkali-free recyclable decarboxylation reaction based on water-soluble uranyl salts according to claim 1, wherein the electron-deficient olefin compound is any one of maleinitriles, acrylic esters, benzenesulfonylethylenes and vinyl ketones.
4. 4. The method for the photocatalytic alkali-free recyclable decarboxylation reaction based on water-soluble uranyl salt according to claim 1, wherein the water-soluble uranyl salt is uranyl nitrate hexahydrate; the addition amount of the water-soluble uranyl salt is 1-10 mol% of the molar amount of the carboxylic acid compound.
5. 5. The method for the photocatalytic alkali-free recyclable decarboxylation reaction based on water-soluble uranyl salts according to claim 1, wherein the reaction medium containing water is water or a mixed solvent of water and an organic solvent.
6. 6. The method for the photocatalytic alkali-free recyclable decarboxylation reaction based on water-soluble uranyl salt according to claim 1, wherein the ratio of the added amounts of carboxylic acid compound and electron deficient olefin compound is 1.5:1.
7. 7. The method for the photocatalytic alkali-free recyclable decarboxylation reaction based on water-soluble uranyl salts according to claim 1, wherein the visible light is blue light with a wavelength ranging from 440 to 445 nm.
8. 8. The method for the photocatalytic alkali-free recyclable decarboxylation reaction based on water-soluble uranyl salt according to claim 1, wherein the addition reaction is carried out under the protection of nitrogen, and the time of the addition reaction is 24h.
9. 9. The method for the alkali-free recyclable decarboxylation reaction based on the photocatalysis of water-soluble uranyl salt according to claim 1, wherein the organic phase is extracted and separated after the completion of the addition reaction, and the obtained aqueous phase containing the catalyst is directly used for the next round of reaction, so that the recycling of the catalyst is realized.

Description

Alkali-free recyclable decarboxylation reaction method based on photocatalysis of water-soluble uranyl salt Technical Field The invention belongs to the technical field of organic synthesis, and particularly relates to an alkali-free recyclable decarboxylation reaction method based on photocatalysis of water-soluble uranyl salt. Background Decarboxylation is one of the core strategies for constructing carbon-carbon bonds in organic synthesis, and is widely applied to the synthesis and preparation of drug molecules, functional materials and natural products. With the deep green chemistry concept, the photocatalytic decarboxylation reaction has the advantages of mild reaction conditions, high atom economy, environmental friendliness and the like, and becomes a research hot spot in recent years. The traditional photocatalytic decarboxylation system mostly depends on noble metal complex photocatalysts, such as iridium-based and ruthenium-based complexes, and the catalyst has the defects of high price and scarce resources although the catalytic activity is excellent, so that the catalyst is not beneficial to large-scale industrial application. Meanwhile, part of the system adopts an organic photocatalyst with a complex structure, and the catalyst is often prepared by multi-step synthesis, so that the operation cost and the time cost of the reaction are obviously improved. In addition, the traditional photocatalytic decarboxylation reaction is usually carried out under alkaline conditions, and the carboxylic acid raw material is converted into a carboxylate form to realize activation by adding alkali into a reaction system, so that the operation not only increases the reaction steps, but also is easy to generate side reaction with sensitive functional groups in the reaction system, the compatibility of the functional groups of a substrate is severely limited, and the application range of the method is further narrowed. To solve the above problems, researchers have tried to develop inexpensive metal salts instead of noble metal catalysts, for example, transition metal salts such as iron salts, copper salts, etc., which have been reported to be applicable to photocatalytic decarboxylation reactions. However, the cheap metal salt-based catalytic system has the common problem of low catalytic efficiency, is difficult to meet the requirement of high-efficiency synthesis, and metal ions such as iron, copper and the like are easy to react with alkali in an aqueous phase reaction system to generate hydroxide precipitates, so that the catalyst is difficult to recycle, the catalyst cannot be recycled, the waste of the catalyst is caused, the difficulty of post-reaction treatment is increased, and the development requirement of green chemistry is not met. Uranium is an actinide with rich reserves, and common uranyl ions (UO 22+) have unique photochemical properties, can generate a ligand-to-metal charge transfer (LMCT) process under the excitation of visible light, generate excited state species with strong oxidizing capability and hydrogen extraction capability, and can be theoretically applied to organic synthesis reactions as a photocatalyst with excellent performance. However, the application of uranyl ions in the field of photocatalytic synthesis is still in a preliminary exploration stage at present, the catalytic potential of uranyl ions in the decarboxylation reaction is not fully exploited, and particularly, the technical scheme for constructing carbon-carbon bonds by high-efficiency and recyclable photocatalytic decarboxylation under the alkali-free condition is not reported so far. Therefore, a method for the photocatalytic decarboxylation reaction based on uranyl ions is developed, so that the efficient decarboxylation under the alkali-free condition is realized, the recycling problem of the catalyst is solved, and the method has important significance for promoting the industrial application of the photocatalytic decarboxylation reaction. Disclosure of Invention In order to solve the problems in the prior art, the invention provides an alkali-free recyclable decarboxylation reaction method based on water-soluble uranyl salt photocatalysis. In the method, in alkali-free, water-phase or water-organic mixed solvent, soluble uranyl salt is used as a photocatalyst to realize decarboxylation addition reaction of carboxylic acid and electron-deficient olefin, and the catalyst can be conveniently recovered and recycled. In order to achieve the above purpose, the present invention provides the following technical solutions: the invention provides an alkali-free recyclable decarboxylation reaction method based on water-soluble uranyl salt photocatalysis, which comprises the following steps of: Under the alkali-free condition, a carboxylic acid compound, an electron-deficient olefin compound and a water-soluble uranyl salt are mixed, a reaction medium containing water is added to obtain a mixture, and then the mixture is