CN-117902966-B - Synthesis method of aromatic aldehyde

CN117902966BCN 117902966 BCN117902966 BCN 117902966BCN-117902966-B

Abstract

The invention discloses a synthesis method of aromatic aldehyde, which comprises the following steps of reacting a compound shown in a formula I and a compound shown in a formula II in an organic solvent containing a photocatalyst, a nickel catalyst, a ligand, alkali and water under blue light irradiation to obtain the aromatic aldehyde shown in a formula III, wherein the formula I, the formula II and the formula III have the following structures, and a ring A is selected from benzene, pyridine, thiophene, furan, pyridazine, indazole, indole, isoquinoline, quinoline, naphthalene, benzothiophene, dibenzofuran or dibenzothiophene; The invention generates formyl radicals under the catalysis of nickel synergistic photooxidation reduction, realizes the formylation of bromobenzene and derivatives thereof in a simple and efficient one-pot manner, constructs aromatic aldehyde, and has the characteristics of cheap and easily obtained raw materials, mild reaction conditions, controllable synthesis process, high separation yield/yield, environment friendliness, wide substrate applicability and the like.

Inventors

YANG HUA
XIANG HAOYUE
GAO JIE
CHEN KAI
HE XIANCHEN

Assignees

中南大学

Dates

Publication Date: 20260512
Application Date: 20240115

Claims (4)

1. A method for synthesizing aromatic aldehyde, which is characterized by comprising the following steps: In an inert atmosphere, reacting a raw material compound with a compound shown in a formula II in an organic solvent containing a photocatalyst, a nickel catalyst, a ligand, alkali and water under the irradiation of blue light, and converting Br groups in the raw material compound into aldehyde groups to obtain aromatic aldehyde; the raw material compound is selected from the following structures: ; Formula II is as follows: ; the photocatalyst comprises [ Ir (dF (one or any combination of CF 3 )ppy) 2 (dtbbpy)][PF 6 ]、Ir(ppy) 2 dtbbpyPF 6 and 4 CzIPN; the dosage of the photocatalyst is 0.8-1.2% of the molar quantity of the compound shown in the formula II); the nickel catalyst comprises one or a combination of nickel bromide and nickel diacetylacetone, wherein the dosage of the nickel catalyst is 10-15% of the molar weight of a compound shown in a formula II; the ligand comprises one or any combination of bipyridine, 4-di-tert-butylbipyridine and 4, 4-di-methoxy bipyridine, wherein the dosage of the ligand is 10-15% of the molar amount of the compound shown in the formula II; The alkali adopts strong alkali weak acid salt, and the dosage of the alkali weak acid salt is 150-200% of the molar weight of the compound shown in the formula II; The mol ratio of the water to the compound shown in the formula II is (20-30): 1; the reaction temperature is 20-35 ℃.
2. The method for synthesizing an aromatic aldehyde according to claim 1, wherein the molar ratio of the raw material compound to the compound represented by formula II is (1.8 to 2.2): 1.
3. The method for synthesizing an aromatic aldehyde according to claim 1, wherein the organic solvent is dichloroethane.
4. The method for synthesizing aromatic aldehyde according to claim 1, wherein the reaction time is 20 to 30 hours.

Description

Synthesis method of aromatic aldehyde Technical Field The invention belongs to the technical field of organic compounds and organic synthesis, and particularly relates to a synthesis method of aromatic aldehyde. Background Aromatic aldehydes, which are one of the most widely used intermediates in the synthesis of drugs, fragrances, fine chemicals and natural products, have a great industrial value as an important chemical raw material, and thus the synthesis of aromatic aldehydes has been a hot spot of interest to organic and pharmaceutical chemists and a very challenging field for decades. Although aromatic aldehydes are extremely widely used, their preparation is very limited. In conventional methods for preparing aromatic aldehydes, such as by adding grignard reagents to N, N-Dimethylformamide (DMF) at low temperatures, the aromatic aldehydes are regionally controlled at the expense of functional group compatibility. The most common method for synthesizing aromatic aldehydes to date is palladium-catalyzed reductive carbonylation of aryl iodides and bromides, which was first reported by Heck in 1974, which was accomplished in synthesis gas (1:1 h 2/CO) at 100 atmospheres at 150 ℃. Although this reaction has been carried out on a ton scale, it still has certain limitations due to the use of both highly toxic carbon monoxide and the use of dedicated equipment for the treatment of high pressure synthesis gas. To develop a more environmentally friendly process, the Stille and Buchman subjects report the use of alternative condensed phase reducing agents and CO alternatives (such as crystalline N-formylsaccharin) to efficiently effect selective formylation of halogenated aromatic hydrocarbons. Nevertheless, the reductive formylation reaction is still limited to simple aromatic hydrocarbons due to the use of high reaction temperatures and stoichiometric amounts of reducing agents. Thus, the development of more easily operated and gentle reaction schemes to synthesize aromatic aldehydes is a hotspot and difficulty in current research. Disclosure of Invention The invention aims to solve the technical problems of overcoming the defects and the shortcomings in the background art and providing a green and mild method for synthesizing aromatic aldehyde. In order to solve the technical problems, the technical scheme provided by the invention is as follows: a method for synthesizing aromatic aldehyde, comprising the following steps: Reacting a compound shown in a formula I with a compound shown in a formula II in an organic solvent containing a photocatalyst, a nickel catalyst, a ligand, alkali and water under the irradiation of blue light to obtain aromatic aldehyde shown in a formula III; Formula I, formula II and formula III are the following structures: Wherein ring a is benzene, pyridine, thiophene, furan, pyridazine, indazole, indole, isoquinoline, quinoline, naphthalene, benzothiophene, dibenzofuran, or dibenzothiophene; r is selected from F, cl, CH 3、t-Bu、OCH3、OBn、COOMe、CH2OH、C(CH3)2 OH, ph, Wherein the method comprises the steps ofRepresents a ligation site; x is selected from Br, cl, I or OTs; the number n=0, 1 or 2 of R. As a further improvement, the photocatalyst comprises [ Ir (dF (one or any combination of CF 3)ppy)2(dtbbpy)][PF6]、Ir(ppy)2dtbbpyPF6 or 4 CzIPN; and/or The nickel catalyst comprises one or a combination of nickel bromide or nickel diacetylacetone, and/or The ligand comprises one or any combination of bipyridine, 4-di-tert-butylbipyridine or 4, 4-di-methoxy bipyridine. As a further improvement, the amount of the photocatalyst is 0.8-1.2% of the molar amount of the compound shown in the formula II. As a further improvement, the nickel catalyst is used in an amount of 10-15% of the molar amount of the compound shown in the formula II. As a further improvement, the dosage of the ligand is 10-15% of the molar quantity of the compound shown in the formula II. As a further improvement, the alkali adopts strong alkali weak acid salt, and the dosage of the alkali is 150-200% of the molar quantity of the compound shown in the formula II. As a further improvement, the molar ratio of the water to the compound shown in the formula II is (20-30): 1. As a further improvement, the molar ratio of the compound shown in the formula I to the compound shown in the formula II is (1.8-2.2): 1. As a further improvement, the organic solvent is dichloroethane. As a further improvement, the reaction temperature is 20-35 ℃ and the reaction time is 20-30 h. Compared with the prior art, the invention has the beneficial effects that: The invention generates formyl radicals under the catalysis of nickel synergistic photooxidation reduction, realizes the formylation of bromobenzene and derivatives thereof in a simple and efficient one-pot manner, constructs aromatic aldehyde, and has the characteristics of cheap and easily obtained raw materials, mild reaction conditions, controllable synthesis process, high separation yiel