Method for synthesizing alpha-benzyl benzofuran compound

A technology of benzofuran and compounds, which is applied in the field of organic synthesis and preparation, can solve the problems of unseen substrate expansion, etc., and achieve the effect of easy synthesis and good substrate applicability

Pending Publication Date: 2021-04-13
SUZHOU UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, there are still relatively few methods for the alkylation of the α-position on the benzofuran skeleton, and there are obvious limitations
For example, Yoshiaki's research group used an air-sensitive zero-valent nickel catalyst to realize the hydroheteroarylation reaction of styrene and benzofuran, but this is only one example, and no substrate expansion has been seen (see Nakao, Y.; Kashihara, N. ; Kanyiva, K. S.; Hiyama, T. Angew. Chem., Int. Ed. 2010, 49 ,4451)

Method used

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  • Method for synthesizing alpha-benzyl benzofuran compound
  • Method for synthesizing alpha-benzyl benzofuran compound
  • Method for synthesizing alpha-benzyl benzofuran compound

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] Embodiment one: Ni[P(OEt) 3 ]{[R`NC(CH 3 )C(CH 3 )NR]C}Br 2 (R` = 2,4,6-trimethylphenyl) synthesis

[0033] Under argon protection, nitrogen heterocyclic carbene [R`NC(CH 3 )C(CH 3 )NR`]C (0.3325 g, 1.0 mmol) was added to the tetrahydrofuran solution of bis(triethylphosphite)nickel(II) bromide (0.5508 g, 1.0 mmol), reacted at room temperature for 2 hours, and removed in vacuo Solvent, wash the residue with n-hexane, extract the residue with toluene, transfer the clear liquid and remove the solvent toluene to obtain a red solid that is a mixed nickel (II) complex with a yield of 85%, which is used as a catalyst for the following implementation For example, catalyzing the hydroheteroarylation reaction of aryl vinyl compounds and benzofuran compounds to prepare the product α-benzylbenzofuran compounds; and the catalyst does not change color in the air for two days, which can prove that the catalyst of the present invention Good stability in air.

[0034] The product...

Embodiment 2

[0042] Example 2 The divalent nickel (II) complex is used as a catalyst to catalyze the hydroheteroarylation reaction of styrene and benzofuran

[0043] Under the protection of argon, the catalyst (35.9 mg, 0.05 mmol, 10 mol%), sodium tert-butoxide (48 mg, 0.5 mmol), and benzofuran (55 μl, 0.5 mmol) were sequentially added to the reaction flask , styrene (86 μl, 0.75 mmol), toluene (1.5 ml) as solvent, at 110 o The reaction was carried out at C for 48 hours, and the reaction was terminated with water. The reaction product was extracted with ethyl acetate, separated and purified by column chromatography (using petroleum ether as a developing agent), and the yield was 92%. The product structural formula was as follows:

[0044]

[0045] Dissolve the product in CDCl 3Medium (about 0.4 mL), seal the tube, measure and characterize on a Unity Inova-400 NMR instrument at room temperature: 1 H NMR (400 MHz, CDCl 3 ): δ 7.61 (dd, J = 7.4, 1.9 Hz, 1H), 7.51 (dd, J =6.9, 2.3 Hz, 1H...

Embodiment 3

[0048] Example 3 The divalent nickel (II) complex is used as a catalyst to catalyze the hydroheteroarylation reaction of o-methoxystyrene and benzofuran

[0049] Under the protection of argon, the catalyst (35.9 mg, 0.05 mmol, 10 mol%), sodium tert-butoxide (48 mg, 0.5 mmol), and benzofuran (55 μl, 0.5 mmol) were sequentially added to the reaction flask , o-methoxystyrene (100 μl, 0.75 mmol), toluene (1.5 ml) as solvent, at 110 o The reaction was carried out at C for 48 hours, and the reaction was terminated with water. The reaction product was extracted with ethyl acetate, separated and purified by column chromatography (petroleum ether was used as the developing solvent), and the yield was 90%.

[0050] Dissolve the product in CDCl 3 Medium (about 0.4 mL), seal the tube, measure and characterize on a Unity Inova-400 NMR instrument at room temperature: 1 H NMR (400 MHz, CDCl 3 ): δ 7.63 – 7.57 (m, 1H), 7.49 (d, J = 7.8 Hz, 1H),7.35 – 7.27 (m, 3H), 7.21 (dd, J = 7.8, 1.7 Hz...

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Abstract

The invention discloses a method for synthesizing an alpha-benzyl benzofuran compound, which comprises the following step of: reacting a benzofuran compound and an aryl ethylene compound serving as raw materials in a solvent in the presence of a catalyst and organic alkali in an inert gas atmosphere to obtain the alpha-benzyl benzofuran compound. Compared with the existing method, the method disclosed by the invention has the advantages that the direct use of an air-sensitive zero-valent nickel complex as a catalyst is avoided, and the applicability of the substrate is obviously expanded; provided is a novel method for producing the alpha-benzyl benzofuran compound by a hydroheteroarylation reaction of an arylethene compound and a benzofuran compound, said method being achieved by an air-stable divalent nickel-based catalyst.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis preparation, and in particular relates to a method for synthesizing α-benzylbenzofuran compounds. Background technique [0002] Benzofuran and its derivatives not only widely exist in natural products and bioactive molecules, but also are general structural units for the construction of drug molecules (see Horton, D. A.; Bourne, G. T.; Smythe, M. L. Chem. Rev. 2003, 103 , 893). In benzofuran derivatives, the alkylation of the β-position on the benzofuran backbone can now be catalyzed by Lewis or Bronsted acids (see Rueping, M.; Nachtsheim, B. J. Beilstein J. Org. Chem. 2010, 6 , 6). However, there are still relatively few methods for the alkylation of the α-position on the benzofuran skeleton, and there are obvious limitations. For example, Yoshiaki's research group used an air-sensitive zero-valent nickel catalyst to realize the hydroheteroarylation reaction of styrene and ben...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D307/79C07D307/81C07F7/08C07D307/80C07D409/06B01J31/22B01J31/18
CPCB01J31/185B01J31/2273B01J2531/0233B01J2531/0238B01J2531/847C07D307/79C07D307/80C07D307/81C07D409/06C07F7/0812
Inventor 孙宏枚水雨李文俊
Owner SUZHOU UNIV
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