Green synthesis method of alpha-thioenamine compound

Abstract

A green synthesis method of an alpha-thioenamine compound includes dissolving a sulfur phenol compound, an electrolyte and an enamine compound in a solvent and powering on for reaction in the nitrogenatmosphere to obtain the alpha-thioenamine compound. A reaction equation in the synthesis method is defined in the description, wherein R1 is methyl, allyl or phenyl; R2 is phenyl of various functional groups substituted at 2-, 3-, or 4-, or a naphthalene ring, or substituted furan or substituted thiophene; Ar is phenyl of various functional groups substituted at 2-, 3-, or 4-, or the naphthalenering, or substituted thiazole, substituted oxazole, substituted thiadiazole, substituted imidazole or substituted tetrazole. The method is simple and efficient in synthesis process, high in atomic economy and environmentally friendly. The reaction operation is simple, the reaction condition is mild, and high temperature is not required.

Description

technical field [0001] The invention belongs to the technical field of chemistry, and in particular relates to a synthesis method of thioenamine compounds. Background technique [0002] As an important structural unit, α-thioenamine widely exists in the molecules of drugs and natural products. In recent years, the development of effective methods for the synthesis of thioenamines has been the focus of research by researchers. Among them, the most straightforward strategy for the synthesis of thioalkenes is the direct cross-dehydrogenative coupling of alkenes with thiols / thiophenols. However, stoichiometric amounts of oxidants and metal catalysts are often required in these transformations. [0003] Traditionally, the C–H bond thiolation of enamines is achieved by the addition of benzenesulfenyl chloride (PhSCl) to alkenes followed by the elimination of HCl. This method was jointly discovered by Tokumitsu and Hayashi in 1977. However, benzenesulfenyl chloride is highly to...

AI Technical Summary

Problems solved by technology

[0005] This traditional method has the following defects: 1, benzenesulfenyl chloride is highly toxic, and it is easy to cause danger if handled carelessly, and there is a great potential safety hazard

2. The use of benzenesulfenyl chloride still causes the reaction to face problems such as poor functional group tolerance and limited functional group tolerance

3. The use of benzenesulfenyl chloride in the reaction brings inconvenience to industrial large-scale production

4. The addition of benzenesulfenyl chloride produces HCl gas, which may put forward higher requirements for industrial equipment and increase the cost of industrial production

5. The atom economy of the reaction is not high

[0008] This method has the following defects: 1, disulfide needs to be prepared by thiophenol, and the atom economy of the reaction is poor

2. The use of equivalent (1.2 times) silver acetate not only causes a large amount of chemical waste, but also brings a large amount of metal residues

3. Silver acetate is expensive and expensive, so it is not suitable for large-scale industrial production

4. The reaction requires a higher reaction temperature, which will cause the reaction to face problems such as poor tolerance of functional groups and limited tolerance of functional groups

5. The use of additional metal catalysts does not meet the requirements of green chemistry and sustainable chemical development

[0011] This method has the following defects: 1, the use of equivalent potassium iodate will not only produce a large amount of chemical waste, but also does not meet the requirements of green chemistry and sustainable chemical development

2. The use of potassium iodate will increase the cost of production and is not suitable for large-scale industrial production

3. Air as an oxidant seems to be green and environmentally friendly, but heating the air to 80 degrees will bring a lot of heat loss, which actually increases the production cost in disguise

[0014] This method has the following defects: 1, the use of metal palladium can bring the problem of metal residue; 2, the use of equivalent oxidant copper acetate will not only produce a large amount of chemical waste, but also the problem of metal residue; 3, additional The use of metal catalysts and oxidants does not meet the requirements of green chemistry and sustainable chemical development; 4, metal palladium catalysts and copper acetate are expensive, and the cost is high, so they are not suitable for large-scale industrial production; increase the cost of industrial production

[0017] This technology has the following defects: 1, the use of iodine will not only produce a large amount of chemical waste, but also does not meet the requirements of green chemistry and sustainable chemical development; 2, the use of iodine will cause the increase of production costs, and the subsequent removal of iodine It will also increase the production cost; 3. The oxidizing agent and higher reaction temperature will also cause the reaction to face problems such as poor tolerance of functional groups and limited tolerance of functional groups

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