阅读说明：本技术 一种卟啉钴(ii)/锌(ii)盐协同催化氧化环烷烃的方法 (Method for oxidizing cycloparaffin through synergetic catalysis of cobalt (II)/zinc (II) porphyrin salt ) 是由 沈海民 宁磊 佘远斌 于 2019-08-28 设计创作，主要内容包括：一种卟啉钴(II)/锌(II)盐协同催化氧化环烷烃的方法,所述方法包括：将卟啉钴(II)和锌(II)盐分散于环烷烃中,密封反应体系,搅拌下升温至100～130℃,通入氧气至0.2～3MPa,保持设定的温度和氧气压力,搅拌反应3～24h,之后反应液经后处理,得到产物环烷醇和环烷酮；本发明所述方法,环烷醇和环烷酮选择性高,有效抑制了脂肪族二酸的生成；助催化剂廉价易得,环烷醇和环烷酮合成成本低；脂肪族二酸选择性低,也有利于环烷烃氧化过程的连续化和产品的分离；具有解决工业上环烷烃催化氧化过程中,环烷醇和环烷酮易于深度氧化生成脂肪族二酸的潜力；本发明是一种高效、可行的环烷烃选择性催化氧化新方法。(A method for the concerted catalytic oxidation of cycloalkanes with a cobalt (II)/zinc (II) porphyrin salt, said method comprising: dispersing cobalt (II) porphyrin and zinc (II) porphyrin into cycloparaffin, sealing a reaction system, heating to 100-130 ℃ under stirring, introducing oxygen to 0.2-3 MPa, keeping the set temperature and oxygen pressure, stirring for reaction for 3-24 hours, and then carrying out post-treatment on reaction liquid to obtain a product of cycloalkanol and cycloalkanone; according to the method, the selectivity of the cycloalkanol and the cycloalkanone is high, and the generation of aliphatic diacid is effectively inhibited; the cocatalyst is cheap and easy to obtain, and the synthesis cost of the cycloalkanol and the cycloalkanone is low; the aliphatic diacid has low selectivity, and is beneficial to the continuous oxidation of the naphthenic hydrocarbon and the separation of products; the method has the potential of solving the problem that in the industrial catalytic oxidation process of the cycloalkane, the cycloalkanol and the cycloalkanone are easy to deeply oxidize to generate aliphatic diacid; the invention is a new efficient and feasible selective catalytic oxidation method of cycloalkanes.)

1. A method for the concerted catalytic oxidation of cycloalkanes with a cobalt (II)/zinc (II) porphyrin salt, said method comprising:

Dispersing cobalt (II) porphyrin and zinc (II) porphyrin into cycloparaffin, sealing a reaction system, heating to 100-130 ℃ under stirring, introducing oxygen to 0.2-3 MPa, keeping the set temperature and oxygen pressure, stirring for reaction for 3-24 hours, and then carrying out post-treatment on reaction liquid to obtain a product of cycloalkanol and cycloalkanone;

The ratio of the quantities of cobalt (II) porphyrin to cycloparaffin is 1: 1000000-500;

The ratio of the amount of zinc (II) salt to the amount of cycloalkane is 1: 2000-20 parts;

The cycloalkane is: one or a mixture of more than two of cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane and cyclodecane in any proportion;

The zinc (II) salt is a mixture of one or more than two of zinc acetate and hydrate thereof, zinc sulfate and hydrate thereof, zinc chloride and hydrate thereof, zinc nitrate and hydrate thereof, zinc carbonate and hydrate thereof, and zinc acetylacetonate and hydrate thereof in any proportion;

The cobalt (II) porphyrin is at least one of the compounds shown in the formula (I):

In the formula (I), R₁、R₂、R₃、R₄、R₅Each independently is: hydrogen, methyl, ethyl, propyl, butyl, isopropyl, tert-butyl, phenyl, 1-naphthyl, 2-naphthyl, methoxy, ethoxyA group, hydroxyl, mercapto, amino, methylamino, ethylamino, dimethylamino, 1-hydroxyethyl, nitro, cyano, carboxyl, benzyl, fluoro, chloro, bromo, or iodo.

2. The process for the concerted catalytic oxidation of cycloalkanes with a cobalt (II)/zinc (II) porphyrin salt according to claim 1 wherein the ratio of the amount of cobalt (II) porphyrin to cycloalkane is 1: 100000-1000.

3. The process for the concerted catalytic oxidation of cycloalkanes with a cobalt (II)/zinc (II) porphyrin salt according to claim 1 wherein the ratio of the amount of zinc (II) salt to the amount of cycloalkane species is 1: 1000 to 100.

4. The method for the co-catalytic oxidation of cycloalkane with a cobalt (II)/zinc (II) porphyrin salt according to claim 1, wherein the stirring rate is 100 to 1500 rpm.

5. The method of claim 1 wherein the cobalt (II)/zinc (II) porphyrin salt synergistically catalyzes the oxidation of cycloalkane, wherein the zinc (II) porphyrin salt is zinc acetate or zinc acetylacetonate.

6. The process for the concerted catalytic oxidation of cycloalkanes with a cobalt (II)/zinc (II) porphyrin salt according to claim 1 wherein the cobalt (II) porphyrin is: 5,10,15, 20-tetrakis (4-chlorophenyl) porphyrin cobalt (II), 5,10,15, 20-tetrakis (2-chlorophenyl) porphyrin cobalt (II), 5,10,15, 20-tetrakis (3-chlorophenyl) porphyrin cobalt (II), 5,10,15, 20-tetrakis (2, 6-dichlorophenyl) porphyrin cobalt (II), 5,10,15, 20-tetrakis (2, 4-dichlorophenyl) porphyrin cobalt (II) or 5,10,15, 20-tetrakis (2,3,4,5, 6-pentafluorophenyl) porphyrin cobalt (II).

Technical Field

the invention relates to a novel method for preparing cycloalkanol and cycloalkanone by selective oxidation of cycloalkane with molecular oxygen under the synergetic catalysis of cobalt (II)/zinc (II) porphyrin salt, belonging to the field of organic catalysis and fine organic synthesis.

Background

Catalytic oxidation of cycloalkanes is an important chemical conversion process, and oxidation products of cycloalkanol and cycloalkanone are not only important organic solvents, but also important fine chemical intermediates, and are widely used for synthesis of fine chemical products such as pesticides, medicines and dyes (WO 2019046316; WO 2019030294; WO 2019069911; CN 108864082; CN 109180556; Journal of Medicinal Chemistry 2019, 62: 1837-1858; Russian Journal of general Chemistry 2018, 88: 2646-2652). Besides, cycloalkanol and cycloalkanone can be further oxidized to prepare aliphatic diacid, which is an important precursor for preparing various high molecular materials, such as cyclohexanol and cyclohexanone which are main products of catalytic oxidation of cyclohexane, and further oxidation of cyclohexanone can obtain adipic acid which is an important precursor for producing nylon-66 and nylon-6, and the market demand is very large (Applied Catalysis A, General 2019, 575: 120-131; Chemical Engineering science 2019, 203: 163-172; Applied Catalysis A, General 2018, 554: 71-79; Industrial & Engineering Chemistry Research 2017, 56: 15030-15037). Currently, the catalytic oxidation of the cycloalkane in industry is mainly realized by using homogeneous cobalt (II) salt or manganese (II) salt as a catalyst, using molecular oxygen or air as an oxidant, and under the conditions of 130-160 ℃ and 0.80-3.0 MPa (Applied Catalysis A, General 2019, 575: 120-131; Science 2014, 346: 1495-1498). Due to the high reaction temperature, the resulting cycloalkanol and cycloalkanone are susceptible to deep oxidation to aliphatic diacids. Although cycloalkanol and cycloalkanone are raw materials for producing aliphatic diacids, the production of aliphatic diacids during the production of cycloalkanol and cycloalkanone is a problem to be avoided. The generation of aliphatic diacid can block the pipeline in the catalytic oxidation process of the cycloalkane, and is not beneficial to continuous production. Therefore, the development of a new selective catalytic oxidation method of cycloalkanes can improve the selectivity of cycloalkanol and cycloalkanone to the maximum extent and reduce and avoid the generation of aliphatic diacid on the premise of ensuring the conversion rate of cycloalkanes, is an urgent need of cycloalkanes catalytic oxidation industry, has great production and application values, and also has important theoretical research values.

Metalloporphyrin is used as a model compound of cytochrome P-450 and widely applied to biomimetic Catalysis of various organic synthesis reactions, in particular oxidation reactions (ChemSusChem 2019, 12: 684-691; Polydron 2019, 163: 144-152; Journal of Catalysis 2019, 369: 133-142). The metalloporphyrin has an approximately planar molecular structure, so that a metal center with catalytic activity can be exposed in a catalytic system to play a role to the maximum extent, excellent catalytic activity can be shown at 1/1000000-1/100000 of the amount of a substrate, the cost of catalytic oxidation of cycloalkanes can be obviously reduced, and the metalloporphyrin is one of the preferable catalysts for catalytic oxidation of cycloalkanes (ChemUSChem 2019, 12: 684-691; Polyhedron 2019, 163: 144-152; Journal of Catalysis 2019, 369: 133-142). Although metalloporphyrin as a catalyst has the advantages of small catalyst dosage, high catalytic efficiency, easy adjustment of structure, good biocompatibility, environmental protection and the like, the generation of aliphatic diacid cannot be reduced or avoided in the process of catalyzing molecular oxygen to oxidize cycloalkane to prepare cycloalkanol and cycloalkanone. In order to reduce or avoid the generation of aliphatic diacid in the catalytic oxidation process of cycloalkane, porphyrin Co (II) is used as a main catalyst, Zn (II) salt is used as a cocatalyst to catalyze molecular oxygen to oxidize cycloalkane under the condition of no solvent, so that the selectivity of cycloalkanol and cycloalkanone is remarkably improved, the conversion rate of cycloalkane is also improved, and the inhibition of aliphatic diacid in the oxidation process of cycloalkane is realized. Therefore, the method takes porphyrin Co (II) as a main catalyst and Zn (II) salt as a cocatalyst to catalyze molecular oxygen to oxidize cycloalkane under the condition of no solvent, has the potential of solving the problem that cycloalkanol and cycloalkanone are easy to deeply oxidize to generate aliphatic diacid in the catalytic oxidation process of cycloalkane in the industry, has important industrial application value and theoretical research value, and has certain reference value for improving the selectivity of other catalytic oxidation systems.

Disclosure of Invention

The invention aims to provide a novel method for preparing cycloalkanol and cycloalkanone by selective oxidation of cycloalkane with molecular oxygen under the concerted catalysis of porphyrin cobalt (II)/zinc (II) salt.

The technical scheme of the invention is as follows:

A method for the concerted catalytic oxidation of cycloalkanes with a cobalt (II)/zinc (II) porphyrin salt, said method comprising:

dispersing cobalt (II) porphyrin and zinc (II) porphyrin into cycloparaffin, sealing a reaction system, heating to 100-130 ℃ under stirring (preferably 110-120 ℃), introducing oxygen to 0.2-3 MPa (preferably 0.6-1.2 MPa), keeping the set temperature and oxygen pressure, stirring for reaction for 3-24 hours (preferably 8-16 hours), and then carrying out post-treatment on the reaction liquid to obtain the product of cycloalkanol and cycloalkanone;

In the invention, cycloalkane is taken as a raw material, cobalt (II) porphyrin is taken as a main catalyst, zinc (II) salt is taken as a cocatalyst, and molecular oxygen is taken as an oxidant;

The amount ratio of cobalt (II) porphyrin to cycloalkane is 1: 1000000-500, preferably 1: 100000-1000;

The mass ratio of the zinc (II) salt to the cycloalkane is 1: 2000-20, preferably 1: 1000-100;

the stirring speed is 100-1500 rpm, preferably 600-1200 rpm;

The post-treatment method comprises the following steps: after the reaction was completed, triphenylphosphine (PPh) was added to the reaction mixture₃stirring the mixture at room temperature (20-30 ℃) for 30min to generate peroxide, and distilling, decompressing, rectifying and recrystallizing a crude product to obtain an oxidation product, wherein the using amount of the peroxide is 2.5-25% of that of the cycloparaffin substance;

the method for analyzing the reaction result comprises the following steps: after the reaction is finished, peroxide generated by reduction of reaction liquid by triphenylphosphine is sampled and analyzed, acetone is used as a solvent for dilution, toluene is used as an internal standard for gas chromatography, the conversion rate of cycloalkane and the selectivity of cycloalkanol, cycloalkanone and peroxide are calculated, benzoic acid is used as an internal standard for liquid chromatography, and the selectivity of aliphatic diacid is calculated;

in the present invention, the cycloalkane is, for example: one or a mixture of more than two of cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane and cyclodecane in any proportion;

The zinc (II) salt is a mixture of one or more than two of zinc acetate and hydrate thereof, zinc sulfate and hydrate thereof, zinc chloride and hydrate thereof, zinc nitrate and hydrate thereof, zinc carbonate and hydrate thereof, and zinc acetylacetonate and hydrate thereof in any proportion, preferably zinc acetate or zinc acetylacetonate;

The cobalt (II) porphyrin is at least one compound shown in the formula (I), and particularly preferably: 5,10,15, 20-tetrakis (4-chlorophenyl) porphyrin cobalt (II), 5,10,15, 20-tetrakis (2-chlorophenyl) porphyrin cobalt (II), 5,10,15, 20-tetrakis (3-chlorophenyl) porphyrin cobalt (II), 5,10,15, 20-tetrakis (2, 6-dichlorophenyl) porphyrin cobalt (II), 5,10,15, 20-tetrakis (2, 4-dichlorophenyl) porphyrin cobalt (II), or 5,10,15, 20-tetrakis (2,3,4,5, 6-pentafluorophenyl) porphyrin cobalt (II);

In the formula (I), R₁、R₂、R₃、R₄、R₅Each independently is: hydrogen, methyl, ethyl, propyl, butyl, isopropyl, tert-butyl, phenyl, 1-naphthyl, 2-naphthyl, methoxy, ethoxy, hydroxy, mercapto, amino, methylamino, ethylamino, dimethylamino, 1-hydroxyethyl, nitro, cyano, carboxy, benzyl, fluoro, chloro, bromo, or iodo.

The invention has the following beneficial effects:

The method for preparing cycloalkanol and cycloalkanone by oxidizing cycloalkane selectively with molecular oxygen under the synergetic catalysis of the cobalt (II)/zinc (II) porphyrin salt has high selectivity for cycloalkanol and cycloalkanone, and effectively inhibits the generation of aliphatic diacid; the cocatalyst is cheap and easy to obtain, and the synthesis cost of the cycloalkanol and the cycloalkanone is low; the aliphatic diacid has low selectivity, and is beneficial to the continuous oxidation of the naphthenic hydrocarbon and the separation of products; has the potential of solving the problem that naphthenic alcohol and cycloalkanone are easy to deeply oxidize to generate aliphatic diacid in the catalytic oxidation process of the cycloalkane in industry. The invention is a new efficient and feasible selective catalytic oxidation method of cycloalkanes.

Detailed Description

The invention will be further illustrated with reference to specific examples, without limiting the scope of the invention thereto.

Metalloporphyrins used in the present invention are described in Journal of the American Chemical Society 2017, 139: 18590-18597; journal of the American Chemical Society 2018, 140: 6383-6390. All reagents used were commercially available analytical grade.