Application of triarylimidazole compound serving as catalyst in electroorganic synthesis

A triaryl imidazole and organic synthesis technology, applied in organic compound/hydride/coordination complex catalysts, physical/chemical process catalysts, electrolytic organic production, etc., can solve problems that have not been reported in domestic and foreign literature, and achieve remarkable results Scientific significance and application prospect, high yield, easy preparation and separation effect

CN102600892AInactive Publication Date: 2012-07-25BEIJING UNIV OF TECH
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2012-07-25
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention relates to an application of a triarylimidazole compound shown in a formula (I) and serving as a catalyst in electroorganic synthesis. In the formula (I), Ar1, Ar2 and Ar3 represent aryl or substituted aryl, and Ar1, Ar2 and Ar3 are same or different; R represents -H, C1-10 alkyl, benzyl, aryl or cyano. The cation free radical which is formed by the triarylimidazole compound shown in the formula (I) under the electrochemical oxidation condition has stable electrochemical stability, and the triarylimidazole compound can be used as the catalyst in electroorganic synthesis. The catalyst can be used for catalyzing a carbonyl compound represented by an electrochemical oxidation preparation formula (II) of benzyl alcohol or alkylbenzene and can be used for inducing a cyclohexene compound represented by a cation free radical type [4+2] cycloaddition reaction preparation formula (III). Compared with the existing triarylimidazole compound, the catalyst disclosed by the invention is more easily prepared and separated, is high in yield and corresponds to a triphenylamine catalyst in the aspects of catalysis and hole transportation capabilities.
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Description

technical field

[0001] The invention relates to the application of triaryl imidazole compounds as catalysts in electro-organic synthesis. Background technique

[0002] Since Nelson first found in 1966 that the cationic radicals of triphenylamines and their analogs substituted by aryl para-positions are very stable (J.Am.Chem.Soc.1966,88,3498), the compounds containing triarylamine structural units have become Preparation of charge transport materials (J.Phys.Chem.1984, 88, 4707), electroluminescent materials (Rapid Commun.2000, 21, 583), organic semiconductors, two-photon optical storage materials (Chem.Rev.1994, 94, 127) and other important raw materials, but also the intermediates of organic dyes and medicines, and can also be used as catalysts for electrochemical reactions and mild selective oxidation reagents (Top.Curr.Chem.1987, 142, 1). Although the structure of triphenylamine and its derivatives is simple, the synthesis conditions are generally very harsh (Chemical I...

Examples

Embodiment 1

[0017] Example 1: Preparation of 4-methoxybenzaldehyde by catalytic oxidation of 2-(4-bromophenyl)-1-methyl-4,5-diphenyl-1H-imidazole

[0018] Step 1: Synthesis of catalyst 2-(4-bromophenyl)-1-methyl-4,5-diphenyl-1H-imidazole

[0019] Equivalent 1,2-diphenylethanedione, p-bromobenzaldehyde, methylamine, ammonium acetate and 0.015 equivalent of KH 2 PO 4 Mix, heat to 150°C, keep the temperature for about 1.5 hours, then cool to room temperature, and recrystallize the solid with acetone and water to obtain 2-(4-bromophenyl)-1-methyl-4,5-diphenyl- 1H-imidazole, yield: 92%.

[0020]

[0021] Yellow needle; 1 HNMR (400MHz, CDCl 3 ): δ=3.50(s, 3H), 7.15(t, J=7.2Hz, 1H), 7.21(t, J=7.2Hz, 2H), 7.39-7.41(m, 2H), 7.45-7.48(m, 3H), 7.52-7.54(m, 2H), 7.62-7.66(m, 4H).

[0022] Step 2: Catalytic oxidation of 4-methoxybenzyl alcohol by 2-(4-bromophenyl)-1-methyl-4,5-diphenyl-1H-imidazole

[0023] In a 50 mL double-chamber electrolytic cell, dissolve 0.1 mmol of 2-(4-bromophenyl)-1...

Embodiment 2

[0026] Example 2: Preparation of 3-methoxybenzaldehyde by catalytic oxidation of 2-(4-bromophenyl)-1-methyl-4,5-diphenyl-1H-imidazole Step 2 by adding 3-methoxybenzyl Alcohol, other steps are the same as in Example 1 to generate 3-methoxybenzaldehyde, yield: 65%.

[0027]

[0028] 1 HNMR (400MHz, CDCl 3 ): δ=3.88(s, 3H), 7.18-7.19(m, 1H), 7.40(s, 1H), 7.48(d, J=6.4Hz, 2H), 9.98(s, 1H).

Embodiment 3

[0029] Example 3: Preparation of 4-methoxybenzaldehyde by catalytic oxidation of 2-(4-bromophenyl)-1-methyl-4,5-diphenyl-1H-imidazole

[0030] Add 4-methylanisole in step 2, and other steps are the same as in Example 1 to generate 4-methoxybenzaldehyde with a yield of 57%.