阅读说明：本技术 一种芳香乙烯基溴衍生物的制备方法 (Preparation method of aromatic vinyl bromide derivative ) 是由 夏吾炯 赵馨鑫 李冰 苟宝权 于 2020-05-26 设计创作，主要内容包括：一种芳香乙烯基溴衍生物的制备方法,本发明涉及一种芳香乙烯基溴衍生物的制备方法。本发明的目的是为了解决现有方法合成芳香乙烯基溴衍生物反应条件苛刻、底物兼容性差且污染环境的问题,本发明室温下,在氮气气氛下,将炔烃衍生物、溴代芳香环类化合物和催化剂溶解在有机溶剂中,进行光照反应,待反应结束后,旋蒸溶剂,提纯,即完成；本发明解决了现有芳香乙烯基溴衍生物合成需要有毒有害物质激发和过渡金属催化体系导致的产率低、方法环保性差、底物兼容性差的问题,本发明应用于有机合成领域。(The invention discloses a preparation method of an aromatic vinyl bromide derivative, and relates to a preparation method of an aromatic vinyl bromide derivative. The invention aims to solve the problems of harsh reaction conditions, poor substrate compatibility and environmental pollution in the synthesis of the aromatic vinyl bromide derivatives by the existing method, and the method comprises the steps of dissolving alkyne derivatives, brominated aromatic ring compounds and a catalyst in an organic solvent at room temperature in a nitrogen atmosphere, carrying out illumination reaction, rotationally evaporating the solvent after the reaction is finished, and purifying to finish the process; the invention solves the problems of low yield, poor method environmental protection and poor substrate compatibility caused by the need of a toxic and harmful substance excitation and transition metal catalytic system in the existing synthesis of aromatic vinyl bromide derivatives, and is applied to the field of organic synthesis.)

1. A method for preparing aromatic vinyl bromide derivatives is characterized by comprising the following steps:

dissolving alkyne derivatives, brominated aromatic ring compounds and a catalyst in an organic solvent at room temperature in a nitrogen atmosphere, uniformly mixing, placing under the light of blue LEDs for illumination reaction, evaporating the solvent in a rotary manner after the reaction is finished, and separating and purifying through silica gel column chromatography to obtain aromatic vinyl bromide derivatives; wherein the charging molar ratio of the alkyne derivative, the brominated aromatic ring compound and the catalyst is 2: 1: 0.2; wherein the chemical structural formula of the alkyne derivative is as follows:

2. The method according to claim 1, wherein the alkyne derivative is a phenylacetylene compound, an alkyl acetylene compound or an alkynylpropionic acid compound.

3. The method for preparing an aromatic vinyl bromide derivative according to claim 1, wherein the aromatic bromocyclic compound is 4-bromopyridine, 4-cyanoborobenzene or 4-esteroxyborobenzene.

4. The method for preparing an aromatic vinyl bromide derivative according to claim 1, wherein the organic solvent is acetone, acetonitrile, tetrahydrofuran, dichloroethane or dimethylsulfoxide.

5. The method for preparing aromatic vinyl bromide derivatives according to claim 1 or 4, wherein the molar volume ratio of the brominated aromatic ring compound to the organic solvent is 1mmol:10 mL.

6. The method for preparing an aromatic vinyl bromide derivative according to claim 1, wherein the progress of the photoreaction is monitored by TLC.

7. The method of claim 1, wherein the reaction time is 24 to 36 hours under a lamp of blue LEDs.

8. The process for preparing aromatic vinyl bromide derivatives as claimed in claim 1, wherein the solvent used for the separation and purification by silica gel column chromatography is a mixed solvent of petroleum ether and ethyl acetate.

9. The method for preparing an aromatic vinyl bromide derivative according to claim 8, wherein the volume ratio of petroleum ether to ethyl acetate is (10-20): 1.

Technical Field

The invention relates to a preparation method of aromatic vinyl bromide derivatives.

Background

Alkynes are a common class of functional structures, present in a wide variety of valuable structural molecules. Because of its particular structural framework, a great deal of research has been directed to modifying its framework structure. The bifunctional of alkynes is one of the important studies. The highly functionalized olefin obtained by alkyne bifunctional is an important precursor structure for synthesizing complex molecules. Aiming at introducing bromine atoms (Br) into alkyne bifunctional in the research project, the bromine atoms (Br) have wide application in building materials and are common and valuable chemical transformation intermediates.

Currently, many studies on the bifunctional of alkyne derivatives have been reported. Among them, the Atom Transfer Radical Addition (ATRA) strategy is widely applied to the study of implementing the bifunctional of alkyne molecules due to its atom economy. In conventional ATRA processes, the generation of free radicals typically requires a stoichiometric amount of a toxic and harmful initiator such as a peroxide, an organotin reagent, trialkylborane, or high intensity ultraviolet light. In addition, the traditional ATRA method has harsh reaction conditions and poor substrate compatibility. This results in a reduction in the synthetic economics to some extent, with significant environmental pollution and damage. Therefore, in today with more and more serious environmental problems, it is important to efficiently utilize green, pollution-free and renewable light energy. Therefore, the key problem to be solved urgently is to find a method which is green, efficient, mild in condition, simple in method and convenient to operate and is used for synthesizing the aromatic vinyl bromide derivative.

Disclosure of Invention

The invention aims to solve the problems of harsh reaction conditions, poor substrate compatibility and environmental pollution in the synthesis of aromatic vinyl bromide derivatives by the conventional method, and provides a preparation method of the aromatic vinyl bromide derivatives.

The invention relates to an aromatic vinylThe preparation method of the bromine derivative comprises the following steps: dissolving alkyne derivatives, brominated aromatic ring compounds and a catalyst in an organic solvent at room temperature in a nitrogen atmosphere, uniformly mixing, placing under the light of blue LEDs for illumination reaction, after the reaction is finished, evaporating the solvent in a rotary manner, and separating and purifying through silica gel column chromatography to obtain aromatic vinyl bromide derivatives; wherein the charging molar ratio of the alkyne derivative, the brominated aromatic ring compound and the catalyst is 2: 1: 0.2; wherein the chemical structural formula of the alkyne derivative is as follows:wherein R is₁Is a substituted aromatic radical or alkyl radical, R₂Is a hydrogen atom or a carboxyl substituent; the chemical structural formula of the brominated aromatic ring compound is as follows: Ar-Br.

The invention has the beneficial effects that:

the invention provides a simple one-step method for synthesizing aromatic vinyl bromide derivatives. The method selects environment-friendly, green and natural abundant visible light blue light as a free radical initiation condition, and successfully avoids using toxic and harmful initiators. Meanwhile, the method is suitable for phenylacetylene compounds, aliphatic acetylene compounds, terminal acetylene hydrocarbons, non-terminal acetylene hydrocarbons and propargylic acid compounds, greatly increases the compatibility of the substrate, and enriches the variety of the substrate. The method solves the problems of low yield, poor environmental protection and poor substrate compatibility caused by the need of excitation of toxic and harmful substances and a transition metal catalytic system in the existing synthesis of the aromatic vinyl bromide derivative, seeks a route for synthesizing the aromatic vinyl bromide derivative which is green, efficient, mild in condition, simple in method and convenient to operate, and lays a certain foundation for the development of modern industrialization.

Drawings

FIG. 1 shows the preparation of the Z-disubstituted 4- (2-bromo-2-phenylvinyl) pyridine derivative obtained in example 1¹H NMR spectrum;

FIG. 2 shows the preparation of the Z-disubstituted 4- (2-bromo-2-phenylvinyl) pyridine derivative obtained in example 1¹³C NMR spectrum;

FIG. 3 shows the preparation of the type E disubstituted 4- (2-bromo-2-phenylvinyl) pyridine derivative obtained in example 1¹H NMR spectrum;

FIG. 4 shows the preparation of the disubstituted 4- (2-bromo-2-phenylvinyl) pyridine derivative of form E obtained in example 1¹³C NMR spectrum.

Detailed Description