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CN-121990888-A - Method for synthesizing aromatic aldehyde and ketone compounds by catalysis of single-atom photocatalyst

CN121990888ACN 121990888 ACN121990888 ACN 121990888ACN-121990888-A

Abstract

The invention provides a method for synthesizing aromatic aldehyde and ketone compounds by catalysis of a single-atom photocatalyst, and belongs to the technical field. The invention prepares the melem heteroleptic monoatomic photocatalyst by mixing a melem precursor and metal salt, preprocessing and calcining, and then adopts a strategy of photocatalytic C (sp 3 ) -H bond selective oxidation, takes aromatic hydrocarbon shown in a formula I as a raw material, and synthesizes aromatic aldehyde or ketone compounds efficiently through the selective oxidation of the C-H bond under the conditions of the monoatomic photocatalyst and visible light. The catalyst of the invention has simple preparation and low price, can be used for various functionalized substrates, and has good reaction selectivity and efficiency, in addition, the photocatalytic oxidation technology of the method has simple operation, can be amplified to the substrate scale of 200 mmol, and has stable reaction efficiency and great industrial application potential.

Inventors

  • GAO KE
  • SU ZHEN
  • LONG HUA
  • ZHAO RUIRUI
  • LU LIANGQIU
  • XIAO WENJING
  • LIU JING

Assignees

  • 武汉光化学技术研究院

Dates

Publication Date
20260508
Application Date
20241104

Claims (10)

  1. 1. A method for synthesizing aromatic aldehyde and ketone compounds by catalysis of a single-atom photocatalyst is characterized in that aromatic hydrocarbon shown in a formula I is used as a raw material, and the aromatic aldehyde or ketone compounds shown in a formula II are obtained by reaction under the conditions of the single-atom photocatalyst and visible light; ; Wherein R 1 includes, but is not limited to, one of H、2-CH 3 、3-CH 3 、4-CH 3 、2-Cl、3-Cl、4-Cl、4-Br、4-F、4-MeO、4-NO 2 、4-CF 3 、4-COOMe、4-CN、4-CH 2 CN; R 2 includes, but is not limited to, one of H、CH 3 、CH 2 CH 3 、(CH 2 ) 2 CH 3 、OCH 2 CH 3 、C 6 H 5 、(CH 2 ) 2 C 6 H 5 、4-F-C 6 H 4 、 pyridinyl.
  2. 2. The method for synthesizing aromatic aldehyde and ketone compounds under the catalysis of a single-atom photocatalyst according to claim 1, wherein the Shan Yuanzi photocatalyst is a melem-based heteroleptic single-atom photocatalyst.
  3. 3. The method for synthesizing aromatic aldehyde and ketone compounds under the catalysis of a single-atom photocatalyst according to claim 1, wherein the mass ratio of Shan Yuanzi photocatalyst to aromatic hydrocarbon is 0.5-50%.
  4. 4. The method for synthesizing aromatic aldehyde and ketone compounds under the catalysis of a single-atom photocatalyst according to claim 1, wherein the reaction temperature is 20-120 ℃, and the reaction time is more than or equal to 3 h.
  5. 5. The method for synthesizing aromatic aldehyde and ketone compounds under the catalysis of the single-atom photocatalyst according to claim 1, wherein the visible light wavelength range of the reaction is 300-800 nm, and the power is 3-120W.
  6. 6. The method for synthesizing the aromatic aldehyde and ketone compounds by catalyzing through the monoatomic photocatalyst according to claim 2 is characterized by comprising the following steps of mixing a melem precursor with a metal salt, and carrying out pretreatment and calcination to obtain the melem heteroleptic monoatomic photocatalyst.
  7. 7. The method for synthesizing aromatic aldehyde and ketone compounds under the catalysis of a single-atom photocatalyst according to claim 6, wherein the melem precursor includes, but is not limited to, one of cyanamide, dicyandiamide, thiourea, urea and melamine.
  8. 8. The method for synthesizing aromatic aldehyde and ketone compounds under the catalysis of the single-atom photocatalyst according to claim 6, wherein the cation of the metal salt comprises one of NH 4 + 、Zn 2+ 、Cu 2+ 、Ni 2+ 、Co 2+ 、Mg 2+ 、Mn 2+ 、Ca 2+ 、Fe 2+ 、Fe 3+ 、Cr 3+ 、Al 3+ 、W 3+ 、Ti 4+ 、V 5+ , and the anion of the metal salt comprises one of halogen ion and CH 3 COO - 、 NO 3 - 、SO 4 2- .
  9. 9. The method for synthesizing aromatic aldehyde and ketone compounds under the catalysis of a single-atom photocatalyst according to claim 6, wherein the mass of the melem precursor is 1-100 times of that of the metal salt.
  10. 10. The method for synthesizing aromatic aldehyde and ketone compounds under the catalysis of a single-atom photocatalyst according to claim 6, wherein the calcining temperature is 400-600 ℃.

Description

Method for synthesizing aromatic aldehyde and ketone compounds by catalysis of single-atom photocatalyst Technical Field The invention relates to the technical field of catalytic material preparation and organic synthesis, in particular to a method for synthesizing aromatic aldehyde and ketone compounds by catalysis of a single-atom photocatalyst. Background Aromatic aldehyde compounds are important intermediates for preparing various fine chemicals such as perfumes, dyes, medicines, food additives and the like, and have huge market demands. Conventional preparation of such chemicals typically employs a chlorination-hydrolysis process of methyl aromatic hydrocarbon with chlorine, and the use of chlorine and acid in large amounts can cause serious environmental problems. Thus, development of a green and gentle oxidation technique, through selective oxidation of the C (sp 3) -H bond of methyl aromatic hydrocarbon, one-step realization of aromatic aldehyde synthesis is urgent. The photocatalysis organic synthesis using sunlight as energy input is an economical, safe and sustainable synthesis technology. In recent years, heterogeneous photocatalysts with high stability and easy separation are rapidly developed in the field of activation of benzyl C-H bonds. The carbon nitride-based Shan Yuanzi photocatalyst has the advantages of high atomic utilization rate, uniform dispersion of active sites of a homogeneous catalyst and easy separation and recovery of a heterogeneous catalyst, and has wide application prospect in the photocatalytic synthesis of aromatic aldehyde. However, studies of this type of catalyst are still in the initial stage, and the single M-N 4 coordination configuration (M stands for metal) limits the modulation of the metal center electronic structure and the activation capacity of O 2, resulting in lower toluene conversion efficiency (mu mol g -1 h-1 grade). Melem (C 6N10H6) is composed of a triazine structure and is a structural unit of graphite-like carbon nitride (g-C 3N4), and has an electronic structure similar to g-C 3N4 and photocatalytic behavior and rich-NH 2 coordination groups. Is easy to coordinate with metal ions, and the coordination configuration is easy to regulate and control. However, studies on melem-based photocatalysts are very limited at present, and the construction of heteroleptic metal centers is rarely reported. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a method for synthesizing aromatic aldehyde and ketone compounds by catalyzing with a single-atom photocatalyst, which can be used for synthesizing the aromatic aldehyde and ketone compounds under visible light with high efficiency by constructing the melem heteroleptic single-atom photocatalyst and reasonably regulating and controlling the local coordination configuration of single atoms, the activation process of O 2 to superoxide radical (O 2•-) and the photocatalytic C-H bond oxidation performance. In order to achieve the above purpose, the specific technical scheme of the invention is as follows: A method for synthesizing aromatic aldehyde and ketone compounds by catalysis of a single-atom photocatalyst comprises the steps of taking aromatic hydrocarbon shown in a formula I as a raw material, and reacting under the conditions of the single-atom photocatalyst and visible light to obtain the aromatic aldehyde or ketone compounds shown in a formula II; ; Wherein R 1 includes, but is not limited to, one of H、2-CH3、3-CH3、4-CH3、2-Cl、3-Cl、4-Cl、4-Br、4-F、4-MeO、4-NO2、4-CF3、4-COOMe、4-CN、4-CH2CN; R 2 includes, but is not limited to, one of H、CH3、CH2CH3、(CH2)2CH3、OCH2CH3、C6H5、(CH2)2C6H5、4-F-C6H4、 pyridinyl. According to the method, a strategy of selective oxidation of a photocatalytic C (sp 3) -H bond is adopted, aromatic hydrocarbon shown in a formula I is used as a raw material, an aromatic aldehyde or ketone compound is efficiently synthesized through selective oxidation of the C-H bond under the conditions of a single-atom photocatalyst and visible light, electrons (e -) in a valence band of the Shan Yuanzi photocatalyst are excited to transition to a conduction band under the irradiation of the visible light, holes (H +) are reserved in the valence band, aromatic hydrocarbon molecules are excited by H + in the valence band to form a carbon positive free radical (R.cndot.), meanwhile, e - in the conduction band is reduced to O 2 to generate O 2·-, and the R.cndot, O 2·- and protons are combined to form a reaction intermediate, and then the reaction intermediate is converted into the aromatic aldehyde or ketone through a dehydration process. The heteroleptic element is introduced into the coordination center of the metal monoatomic, so that the electronic structure of the metal center can be effectively regulated, the adsorption and activation capacity of the metal center to O 2 can be enhanced, and the oxidation performance of aromatic hydrocarbon C (sp 3) -H bonds can be improve