阅读说明：本技术 一种光催化脱羧转化制备氘代化学品的方法 (Method for preparing deuterated chemicals through photocatalytic decarboxylation conversion ) 是由 王心晨 郑梅芳 施佳乐 袁涛 于 2020-07-22 设计创作，主要内容包括：本发明公开了一种光催化脱羧转化制备氘代化学品的方法,包括以下步骤：羧酸类化合物在光源、催化剂共同催化作用下,与氘源进行脱羧加氘反应,得到氘代化学品；其中所述氘源为氘水、氘代醇类化合物中的一种或多种。本发明以环保、廉价的氘水或氘代试剂替代传统的氘气或复杂含氘有机物作为氘源,反应条件温和,以可见光为驱动能,整个过程绿色、简洁、高效；在光催化的作用下实现在温和的条件下对羧酸类化合物的定位氘化反应。本方法较传统的氘化反应具有更高的选择性、更温和的反应条件以及更经济适用性。(The invention discloses a method for preparing a deuterated chemical by photocatalytic decarboxylation conversion, which comprises the following steps: carboxylic acid compounds and a deuterium source are subjected to decarboxylation and deuterium addition reaction under the combined catalytic action of a light source and a catalyst to obtain deuterated chemicals; wherein the deuterium source is one or more of deuterium water and deuterated alcohol compounds. The invention uses environment-friendly and cheap deuterium water or a deuterium-substituted reagent to replace the traditional deuterium gas or complex organic matters containing deuterium as a deuterium source, has mild reaction conditions, uses visible light as driving energy, and has green, simple and high-efficiency whole process; the localized deuteration reaction of carboxylic acid compounds under mild conditions is realized under the action of photocatalysis. Compared with the traditional deuteration reaction, the method has higher selectivity, milder reaction conditions and more economic applicability.)

1. A method for preparing deuterated chemicals through photocatalytic decarboxylation conversion is characterized by comprising the following steps: the method comprises the following steps: and (2) taking a carboxylic acid compound as a substrate and hexagonal-phase boron-nitrogen-carbon as a photocatalyst, adding a deuterium source and alkali, introducing nitrogen for protection, and stirring and reacting for 48 hours at room temperature under the condition of visible light illumination to synthesize the deuterated chemical.

2. The method of claim 1, wherein: the deuterium source is one or more of deuterium water and deuterated alcohol compounds.

3. The method of claim 1, wherein: an aprotic solvent is also added.

4. The method of claim 1, wherein: the alkali is potassium carbonate or sodium carbonate; the addition amount of the alkali is to regulate and control the pH value of the initial reaction liquid to be 8-10.

5. The method of claim 1, wherein: the mass ratio of the addition amount of the hexagonal phase boron nitrogen carbon to the carboxylic acid compounds is 0.2: 1.

6. The method of claim 1, wherein: and the reaction step also comprises the steps of extracting with ethyl acetate after the reaction is finished, combining organic phases, drying, filtering, and concentrating under reduced pressure to obtain the deuterated compound without column chromatography separation and purification.

7. The method of claim 1, wherein: the hexagonal phase boron nitrogen carbon has a chemical formula ofhBCN, graphite-like structure with a specific surface area of 100-200 m²The absorption band edge is 400-600 nm.

8. The method of claim 7, wherein: the preparation method of the hexagonal phase boron nitrogen carbon comprises the following steps:

(1) grinding and uniformly mixing precursor glucose, urea and boric acid according to the mass ratio of 1:2: 1;

(2) and (2) calcining the solid powder obtained in the step (1) at 1000-1200 ℃ in an ammonia atmosphere to obtain hexagonal phase boron nitrogen carbon.

Technical Field

The invention belongs to the technical field of photocatalytic organic synthesis, and particularly relates to a method for preparing a deuterated chemical through photocatalytic decarboxylation.

Background

Deuterium-substituted chemicals are a key diagnostic tool and provide important information on drug metabolism in drug analysis, pharmacological research, medical diagnosis, residue analysis and other studies. Besides, the deuterium-substituted chemical also has important application in the fields of chemical mechanism research, kinetic research and the like. Therefore, the search and development of new green methods for preparing deuterated compounds have been the research focus of researchers. The great challenge facing this approach is the selective control of deuteration and the universality of the functional groups. Traditional methods involve high temperature, high pressure (deuterium is the source of deuterium), strong acids, strong bases, or expensive metal catalysts. However, the application of deuterium addition (or deuteration) requires the use of deuterium gas or other complex deuterated organic reagents, as well as high temperature, high pressure and noble metal catalysts, greatly limiting the applicability of the deuterium addition reaction. The method takes a simple and cheap carboxylic acid compound as a substrate and a non-metal-based semiconductor as a photocatalyst to realize decarboxylation and deuterium addition reactions, has more universal functional group compatibility and higher chemical selectivity, realizes the synthesis of site-directed deuteration products, and can be used as an ideal strategy for preparing deuterium-containing compounds.

Accordingly, the prior art is yet to be improved and developed.

Disclosure of Invention

In order to solve the defects and shortcomings of the prior art, the invention aims to provide a method for preparing a deuterated chemical through photocatalytic decarboxylation and hydrogenation of a nonmetal-based semiconductor.

The purpose of the invention is realized by the following technical scheme, which comprises the following steps:

1. synthesizing a photocatalyst boron, nitrogen and carbon: chemical formula of boron nitrogen carbon ishBCN, graphite-like structure with a specific surface area of 300-400m²The absorption band edge is 400-600nm, and the method comprises the following steps:

(1) grinding and uniformly mixing precursor glucose, urea and boric acid;

(2) and (2) calcining the solid powder obtained in the step (1) at 1000-1200 ℃ in an ammonia atmosphere to obtain the boron-nitrogen-carbon photocatalyst.

2. Preparation of deuterated chemicals: and (2) adding a carboxylic acid compound serving as a substrate and hexagonal phase boron-nitrogen-carbon serving as a photocatalyst into a reactor, adding a deuterium source, a solvent and alkali, introducing nitrogen for protection, and stirring and reacting for 48 hours at room temperature under the condition of visible light illumination to synthesize the deuterated chemical. After the reaction is finished, extracting with ethyl acetate, combining organic phases, drying, filtering and concentrating under reduced pressure to obtain a final product, wherein the reaction equation is as follows:

wherein aryl is a benzene ring or a pyridine ring. Preferably, the photocatalyst is hexagonal boron nitrogen carbon; the mass ratio of the added amount of the photocatalyst to the substrate is 0.2: 1; the deuterium source is deuterated water or deuterated methanol; the molar ratio of the added amount of the alkali to the substrate is 0.2: 1; the solvent is acetonitrile, dichloroethane or no solvent; the alkali is potassium carbonate or sodium carbonate; the addition amount of the alkali is to regulate and control the pH value of the initial reaction liquid to be 8-10.

The principle of the invention is as follows: under the illumination of visible light, carboxylic acid compounds are decarboxylated to obtain carbon free radicals, and then deuterium in a deuterium source is captured to obtain a deuterated product with high positioning selectivity.

The preparation method of the invention has the following advantages and beneficial effects:

(1) the synthesis method avoids the use of precious metals and other organic deuterium sources, reduces the byproducts caused by the precious metals and other organic deuterium sources, and has the advantages of simple and easy method, mild conditions and safe operation;

(2) the synthesis method disclosed by the invention has the advantages that the heating is not needed, the high yield can be obtained under the visible light illumination at room temperature, the yield can reach 87%, and the energy is saved and the environment is protected;

(3) the synthetic method has the advantages of high step economy, no need of separation and purification, mild reaction conditions and good industrial application prospect.

(4) The catalyst is simple and easy to obtain and can be repeatedly used.

Drawings

FIG. 1 is a diagram showing the equation of the photocatalytic decarboxylation reaction of the carboxylic acid compound of the present invention;

fig. 2 is a specific surface area diagram (a) and an ultraviolet-visible absorption spectrum diagram (B) of the hexagonal boron nitrogen carbon photocatalyst prepared by the present invention.

Detailed Description

The present invention will be described in further detail with reference to examples and drawings, but the present invention is not limited thereto.

Synthesizing a photocatalyst boron, nitrogen and carbon: hexagonal phase boron nitrogen carbon of the formulahBCN, graphite-like structure, specific surface area 339 m²(as shown in FIG. 2A), the absorption band edge is 400-600nm (as shown in FIG. 2B), comprising the following steps:

(1) grinding and uniformly mixing precursor glucose, urea and boric acid according to the mass ratio of 1:2: 1;

(2) and (2) calcining the solid powder obtained in the step (1) at 1200 ℃ in an ammonia atmosphere to obtain the boron-nitrogen-carbon photocatalyst.