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CN-121991098-A - Chiral dinitrogen oxygen ligand based on bipyridine bridging, preparation method thereof and application thereof in asymmetric catalytic reaction

CN121991098ACN 121991098 ACN121991098 ACN 121991098ACN-121991098-A

Abstract

The invention discloses a chiral dinitrogen oxygen ligand based on bipyridine bridging, a preparation method thereof and application thereof in asymmetric catalytic reaction, belonging to the fields of organic synthesis and asymmetric catalysis. The invention provides a bipyridine bridged chiral dinitrogen oxygen ligand, which is formed by connecting two chiral nitrogen oxygen units (spiral ring or long arm structure) with definite structures through rigid bipyridine bone bridging, so that a chiral catalytic microenvironment with high rigidity and definite space orientation is accurately constructed. The structural design effectively integrates the nitrogen atom of bipyridine and the oxygen atom of an nitroxide group as multiple coordination sites, can efficiently coordinate with a plurality of metal ions such as Mn (II), fe (II), co (II), ni (II), cu (II), zn (II) and the like, preferentially generates a stable six-membered ring chelate structure, and thus, the chiral ligand-metal composite material with high performance is prepared, and the chiral ligand-metal composite material has excellent catalytic effect in asymmetric cycloaddition reaction.

Inventors

  • LI SHIWU
  • TIAN XUE
  • ZHAO ZHIFEI

Assignees

  • 石河子大学

Dates

Publication Date
20260508
Application Date
20260130

Claims (10)

  1. 1. The chiral dinitrogen oxygen ligand based on bipyridine bridging is characterized in that the chiral dinitrogen oxygen ligand based on bipyridine bridging is a spiro chiral nitrogen oxide-bipyridine ligand or a long-arm chiral nitrogen oxide-bipyridine ligand; The spiro chiral nitroxide-bipyridine ligand has a structure shown in a formula I: ; in the formula I, ar is phenyl, alkyl substituted phenyl, cycloalkyl substituted phenyl or halogenated phenyl; The long-arm chiral nitrogen oxide-bipyridine ligand has a structure shown in a formula II: ; In formula II, R 1 、R 2 is independently hydrogen, alkyl, halogen substituent or halogenated alkyl, and m is 1 or 2.
  2. 2. The chiral dinitrogen oxygen ligand based on bipyridine bridge according to claim 1, wherein in the formula I, the carbon atom number of alkyl is 1-5 in the alkyl substituted phenyl, the carbon atom number of cycloalkyl is 3-6 in the cycloalkyl substituted phenyl, the halogenated phenyl is fluorinated phenyl or chlorinated phenyl; In the formula II, the carbon number of the alkyl is 1-5, the halogen substituent is fluorine or chlorine, and the halogenated alkyl is trifluoromethyl.
  3. 3. The bipyridine bridged chiral dinitrogen oxygen ligand according to claim 1, wherein the spiro chiral nitrogen oxide-bipyridine ligand has a structure represented by any one of formulas L1 to L6: 。
  4. 4. the bipyridine bridged chiral dinitrogen oxygen ligand according to claim 1, wherein the long-arm chiral nitrogen oxide-bipyridine ligand has a structure represented by any one of formulas L7 to L18: 。
  5. 5. A method for preparing a bipyridine bridged chiral dinitrogen oxygen ligand according to any one of claims 1 to 4, comprising the steps of: taking a compound C or a compound D as a precursor, taking m-chloroperoxybenzoic acid as an oxidant, and performing a nitrogen oxidation reaction in a solvent to obtain the chiral dinitrogen oxygen ligand based on bipyridine bridge; When the compound C is used as a raw material, the product has a structure shown in a formula I; when the compound D is used as a raw material, the product has a structure shown in a formula II; the structure of the compound C is shown as a formula C, and the structure of the compound D is shown as a formula D: 、 。
  6. 6. The preparation method of the organic electroluminescent device according to claim 5, wherein the molar ratio of the precursor to the m-chloroperoxybenzoic acid is 1:2-3, the solvent is chloroform, the concentration of the precursor in the solvent is 0.1-0.2M, and the time of the oxynitride reaction is 20-60 min.
  7. 7. The preparation method according to claim 5, wherein the preparation method of the compound C comprises the following steps: mixing a compound A and 2,2 '-bipyridine-6, 6' -dicarboxaldehyde in an alcohol solvent, and carrying out a bridging reaction to obtain a compound C; The molar ratio of the compound A to the bipyridine-6, 6' -dicarboxaldehyde is 2-3:1, the alcohol solvent is ethanol, the concentration of the compound A in the alcohol solvent is 0.1-0.2M, the temperature of the bridging reaction is 80-85 ℃ and the time is 6-24 hours, and the compound A is shown as follows: 。
  8. 8. the preparation method according to claim 5, wherein the preparation method of the compound D comprises the steps of: mixing a compound B and 2,2 '-bipyridine-6, 6' -dicarboxaldehyde in an alcohol solvent, and carrying out a bridging reaction to obtain a compound D; the molar ratio of the compound B to the bipyridine-6, 6' -dicarboxaldehyde is 2-3:1, the alcohol solvent is ethanol, the concentration of the compound B in the alcohol solvent is 0.1-0.2M, the temperature of the bridging reaction is 80-85 ℃ and the time is 6-24 hours, and the compound B is shown as follows: 。
  9. 9. Use of a bipyridine bridged chiral dinitrogen oxygen ligand according to any one of claims 1 to 4 in an asymmetric catalytic reaction.
  10. 10. A method for asymmetric cycloaddition reaction involving alpha, beta-unsaturated acyl imidazole compounds, which is characterized by comprising the following steps: mixing a 3-vinyl-1H-indole compound, an alpha, beta-unsaturated acyl imidazole compound, a metal Lewis acid, a chiral dinitrogen oxygen ligand based on bipyridine bridging according to any one of claims 1 to 4 and a solvent to perform an asymmetric cycloaddition reaction, thereby completing the preparation.

Description

Chiral dinitrogen oxygen ligand based on bipyridine bridging, preparation method thereof and application thereof in asymmetric catalytic reaction Technical Field The invention relates to the field of organic synthesis and asymmetric catalysis, in particular to a chiral dinitrogen oxygen ligand based on bipyridine bridging, a preparation method thereof and application thereof in asymmetric catalysis. Background Chiral nitroxide ligands, such as bipyridine oxazolines (PyBox) and bisoxazolines (Box), have become key tools in the field of modern asymmetric catalysis. The ligand can coordinate with a metal center to construct a Lewis acid catalyst with definite chiral environment, and the ligand is successfully applied to various enantioselective conversion processes such as cyclopropanation, aldol condensation, mannich reaction and the like. Despite the numerous efforts in this area, current research is directed to the development of novel nitroxide ligands with higher structural rigidity, better chiral transfer efficiency and wider substrate versatility. Wherein two highly structured chiral nitroxide units are linked by a rigid bipyridine bridge and the relative spatial orientation and electronic properties of the two metal coordination sites are precisely controlled, potentially leading to unique catalytic performance. However, a rigid framework such as a spiro framework or a condensed ring framework is further added on the basis of the bipyridine as a rigid framework so as to construct the chiral dinitrogen oxygen ligand with a higher rigid structure, and related literature reports are not yet seen at present. Disclosure of Invention The invention aims to provide a chiral dinitrogen oxygen ligand based on bipyridine bridging, a preparation method thereof and application thereof in asymmetric catalytic reaction, so as to solve the problems in the background art. In order to achieve the above purpose, the present invention provides the following technical solutions: The technical scheme of the invention is that a chiral dinitrogen oxygen ligand based on dipyridine bridge is provided, wherein the chiral dinitrogen oxygen ligand based on dipyridine bridge is a spiro chiral nitrogen oxide-dipyridine ligand or a long-arm chiral nitrogen oxide-dipyridine ligand; The spiro chiral nitroxide-bipyridine ligand has a structure shown in a formula I: ; in the formula I, ar is phenyl, alkyl substituted phenyl, cycloalkyl substituted phenyl or halogenated phenyl; The long-arm chiral nitrogen oxide-bipyridine ligand has a structure shown in a formula II: ; in formula II, R 1、R2 is independently hydrogen, alkyl, halogen substituent or halogenated alkyl, and m is 1 or 2. Preferably, in the formula I, the carbon atom number of the alkyl is 1-5 in the alkyl substituted phenyl, the carbon atom number of the cycloalkyl is 3-6 in the cycloalkyl substituted phenyl, and the halogenated phenyl is fluorinated phenyl or chlorinated phenyl; In the formula II, the carbon number of the alkyl is 1-5, the halogen substituent is fluorine or chlorine, and the halogenated alkyl is trifluoromethyl. Preferably, the spiro chiral nitroxide-bipyridine ligand has a structure shown in any one of formulas L1-L6: 。 preferably, the long-arm chiral nitrogen oxide-bipyridine ligand has a structure shown in any one of formulas L7-L18: ; The second technical scheme of the invention is to provide a preparation method of the chiral dinitrogen oxygen ligand based on bipyridine bridging, which comprises the following steps: taking a compound C or a compound D as a precursor, taking m-chloroperoxybenzoic acid as an oxidant, and performing a nitrogen oxidation reaction in a solvent to obtain the chiral dinitrogen oxygen ligand based on bipyridine bridge; When the compound C is used as a raw material, the product has a structure shown in a formula I; when the compound D is used as a raw material, the product has a structure shown in a formula II; the structure of the compound C is shown as a formula C, and the structure of the compound D is shown as a formula D: 、。 Preferably, the molar ratio of the precursor to the m-chloroperoxybenzoic acid is 1:2-3, the solvent is chloroform, the concentration of the precursor in the solvent is 0.1-0.2M, and the time of the oxynitride reaction is 20-60 min. Preferably, the preparation method of the compound C comprises the following steps: Mixing spiro piperidine amide with a structure shown in a compound A and 2,2 '-bipyridine-6, 6' -dicarboxaldehyde in an alcohol solvent, and carrying out bridging reaction to obtain a compound C; The molar ratio of the compound A to the bipyridine-6, 6' -dicarboxaldehyde is 2-3:1, the alcohol solvent is ethanol, the concentration of the compound A in the alcohol solvent is 0.1-0.2M, the temperature of the bridging reaction is 80-85 ℃ and the time is 6-24 hours, and the compound A is shown as follows: 。 preferably, the preparation method of the compound D comprises the following steps: mixing c