CN109776617B

CN109776617B - Acetone coordination binuclear palladium compound and preparation method and application thereof

Info

Publication number: CN109776617B
Application number: CN201910062494.9A
Authority: CN
Inventors: 余娟; 叶青松; 陈力; 高安丽; 姜婧; 常桥稳; 晏彩先; 李�杰
Original assignee: Kunming Institute of Precious Metals
Current assignee: Kunming Institute of Precious Metals
Priority date: 2019-01-23
Filing date: 2019-01-23
Publication date: 2021-04-27
Anticipated expiration: 2039-01-23
Also published as: CN109776617A

Abstract

The invention discloses an acetone coordination binuclear palladium compound and a preparation method and application thereof. The preparation method of the acetone coordination palladium compound comprises the following steps: with (fluoro) acetylacetone (HF)_xacac) and palladium chloride are used as raw materials to synthesize a compound which takes acetone as a bridge to link two palladium atoms under the condition of mixed liquid of aromatic hydrocarbon and acetone, and the structure is shown as follows. Compared with the prior art, the palladium compound with a brand-new structure is prepared; all the products for catalyzing the Sonogashira coupling reaction are bilateral coupling products, the unilateral coupling products are almost not generated, the excellent reaction activity is shown, the method has better industrialization prospect,

Description

Acetone coordination binuclear palladium compound and preparation method and application thereof

Technical Field

The invention relates to a palladium compound with a new structure, preparation and application thereof, in particular to a compound with two palladium atoms linked by an acetone bridge, a preparation method thereof, and a specific catalytic activity in Sonogashira coupling reaction, belonging to the field of chemistry and chemical engineering.

Background

The coupling reaction is an important reaction for preparing organic photoelectric materials and common important drugs at present, the used catalyst is an organic compound of palladium, and the palladium-based molecular catalyst has the best effect and the most extensive application on the common coupling reaction and is one of the most important industrial catalysts.

Through the development of the palladium-based molecular coupling catalyst for nearly 20 years, a plurality of catalysts are successively proposed: including Pd (F)₃acac)₂、Pd(F₆acac)₂、 Pd_x(dba)_y、Pd(acac)₂Etc., Stefano Nicolai et al Pd (hfacac)₂Oxyalkynylation of a coupling iodide and an olefin, and the like. However, with the increasing demand of human beings for new organic photoelectric materials and new drugs, the original catalyst cannot meet the demand, and a palladium-based molecular coupling catalyst with a new structure needs to be developed to achieve the purposes of high catalytic activity and high selectivity. Fukuda reported that new methylene-coordinated palladium compounds are of interest to various researchers, but the synthetic method would use highly toxic mercury salts; efimenko et al use similar novel compounds from Fukuda and found that methylene-coordinated palladium atoms enhance catalyst activity.

Disclosure of Invention

The invention aims to overcome the defects reported in the prior art and provide a high-activity acetone coordination binuclear palladium compound with a brand-new structure and a preparation method and application thereof, and the compound has higher bilateral selectivity on a product of Sonogashira coupling reaction between 2, 5-dibromothiophene and methylbutynol and between 4, 7-dibromobenzothiadiazole and methylbutynol.

The purpose of the invention can be realized by the following technical scheme:

the molecular structure of the acetone coordination binuclear palladium compound is as follows:

r in the above molecular structure represents a fluoromethyl group CF₃、CHF₂、CH₂F; r' represents hydrogen, C₁～C₁₀A straight-chain or branched alkyl group of (1). The mechanism of formation of the acetone coordinated binuclear palladium compound is as follows:

the preparation method comprises the steps of mixing (fluoro) acetylacetone (HF)_xacac) and palladium chloride are used as raw materials to synthesize a compound which takes acetone as a bridge to link two palladium atoms under the condition of a mixed solution of aromatic hydrocarbon and acetone.

The method comprises the following specific steps: under the protection of nitrogen, Pd (F)_xacac)₂Adding sodium bicarbonate solid into the mixture solution of acetone and toluene in a ratio of 1:1, adjusting the reaction system to be alkalescent, and carrying out reflux reaction for 12 hours to obtain the target compound.

Two acetone molecules are used as ligands, and the oxygen and methylene of the carbonyl group respectively bridge two palladium atoms to form an octa-ring.

R represents fluoromethyl CF₃、CHF₂、CH₂F and chloromethyl CCl₃、CHCl₂、CH₂Cl, and the like.

R' represents hydrogen, C₁～C₁₀Linear or branched alkyl.

The acetone activated palladium catalyst improves the catalytic activity of the acetone activated palladium catalyst, and has important significance in improving the original catalyst and inventing a palladium compound with a brand new structure under the industrial application of the contemporary coupling reaction and the trend of relying on the efficient catalyst.

Detailed Description

Example 1.77g (0.01mol) of palladium chloride was weighed out and dissolved in 20mL of 0.3mol/L diluted hydrochloric acid, 3.1mL (3.00g) of acetylacetone was added slowly with continuous stirring, the reaction was stirred at 70 ℃ for 1 hour, a solution of 0.8g of sodium hydroxide dissolved in 40mL of distilled water was added continuously, the reaction was stirred continuously for 5 hours, the mixture was left to stand, filtered, washed with water until no chloride ion was detected in the washing solution, and dried at 50 ℃ for 8 hours to obtain a pale yellow palladium acetylacetonate solid. The palladium acetylacetonate thus obtained was added to 50mL of a 1:1 mixture of acetone and toluene, and 0.05g of a solid sodium bicarbonate was added to react under nitrogen for 10 hours, followed by filtration to obtain a filtrate, which was concentrated to dryness and dried at 50 ℃ for 1 hour to obtain a dark red granular solid (2.01 g, 38.35% yield). (Pd-1)

Characteristic structure parameters:<1>elemental analysis: found C36.64%, H4.58%, Pd 40.46%;<2>mass spectrum: MS (EI)⁺) m/z:524，[MH]⁺；<3>¹H-NMR(400Hz,DMSO):δ5.0ppm(2H,CH)；2.6ppm(4H,CH₂)； 2.1ppm(6H,CH₃)；1.95ppm(12H,CH₃) And C₁₆H₂₄O₆Pd₂The structural data of (a) is substantially consistent.

Example 2 1.77g (0.01mol) of palladium chloride was weighed out and dissolved in 20mL of 0.3mol/L diluted hydrochloric acid, 3.6mL (4.62g) of trifluoroacetylacetone was slowly added with continuous stirring, the reaction was stirred at 70 ℃ for 1 hour, a solution of 0.8g of sodium hydroxide in 40mL of distilled water was further added, the reaction was further stirred for 5 hours, the mixture was left to stand, filtered, washed with water until no chloride ion was detected in the washing solution, and dried at 50 ℃ for 8 hours to obtain a pale yellow palladium trifluoroacetylacetone solid. The palladium trifluoroacetylacetonate obtained was added to 50mL of a 1:1 mixture of acetone and toluene, 0.05g of a solid sodium bicarbonate was added, the reaction was carried out for 10 hours under nitrogen protection, filtration was carried out, the filtrate was taken, concentrated to dryness and dried at 50 ℃ for 1 hour, and 3.15 g of a dark red granular solid was obtained in 49.84% yield. (Pd-2)

Characteristic structure parameters:<1>elemental analysis: found C30.38%, H2.85%, F10.84%, Pd 33.54%;<2>mass spectrum: MS (EI)⁺)m/z:631，[MH]⁺；<3>¹H-NMR(400Hz,DMSO):δ5.2ppm(2H,CH)；2.7ppm(4H,CH₂)； 2.1ppm(6H,CH₃)；1.98ppm(6H,CH₃) And C₁₆H₁₈F₃O₆Pd₂The structural data of (a) is substantially consistent.

Example 3 1.77g (0.01mol) of palladium chloride was weighed out and dissolved in 20mL of 0.3mol/L diluted hydrochloric acid, 4.24mL (6.24g) of hexafluoroacetylacetone was slowly added with continuous stirring, the reaction was stirred at 70 ℃ for 1 hour, a solution of 0.8g of sodium hydroxide in 40mL of distilled water was further added, the reaction was further stirred for 5 hours, the mixture was left to stand, filtered, washed with water until no chloride ion was detected in the washing solution, and dried at 50 ℃ for 8 hours to obtain a pale yellow palladium hexafluoroacetylacetone solid. The resulting palladium hexafluoroacetylacetonate was added to 50mL of a 1:1 mixture of acetone and toluene, 0.05g of a solid sodium bicarbonate was added, the mixture was reacted for 10 hours under nitrogen, filtered, the filtrate was concentrated to dryness and dried at 50 ℃ for 1 hour to give 4.72g of a dark red granular solid, with a yield of 63.78%. (Pd-3)

Characteristic structure parameters:<1>elemental analysis: found C25.95%, H2.43%, F15.41%, Pd 28.65%;<2>mass spectrum: MS (EI)⁺)m/z:740，[MH]⁺；<3>¹H-NMR(400Hz,DMSO):δ5.4ppm(2H,CH)；2.6ppm(4H,CH₂)； 2.1ppm(6H,CH₃) And C₁₆H₁₈F₆O₆Pd₂The structural data of (a) is substantially consistent.

Example 42, 5-dibromothiophene (1.0equiv.), methylbutynol (3equiv.), catalyst (5 mol% vs. 2, 5-dibromothiophene): pd-1, Pd-2, Pd-3, Pd (PPh)₃)₄As a control in Et₃A mixture of THF and THF (1: 1) (10mL) was reacted at 25 ℃ for 12 h.

Of Compound A¹H NMR(400MHz,CDCl₃):δ(ppm)7.02(d,1H,J＝6.2Hz),6.92(d,1H,J＝6.2 Hz),2.30(bs,1H；2OH),1.62(s,6H；2CH₃) (ii) a Of compounds B¹H NMR(400MHz,CDCl₃):δ(ppm) 6.99(s,2H；2ArH),2.24(bs,2H；2OH),1.60(s,12H；4CH₃).

Example 54, 7-Dibromobenzothiadiazole (1.0equiv.), methylbutynol (3equiv.), Pd catalyst (5 mol% relative to 4, 7-dibromobenzothiadiazole) Pd-1, Pd-2, Pd-3, Pd (PPh)₃)₄As a control in Et₃A mixture of THF and THF (1: 1) (10mL) was reacted at 25 ℃ for 12 hours.

Of Compound A¹H NMR(400MHz,CDCl₃),δ(ppm)＝7.80-7.76(d,1H,J＝7.6Hz,ArH), 7.57-7.55(d,1H,J＝7.6Hz,ArH),1.71(s,6H,2CH₃) (ii) a Of compounds B¹H NMR(CDCl₃,400MHz): δ(ppm)＝7.61(s,2H,2ArH),3.09(bs,2H,2OH),1.71(s,12H,4CH₃).

Claims

1. An acetone-coordinated binuclear palladium compound, characterized in that: the structure of the compound

The structure is as follows:

two acetone molecules are used as ligands, and the oxygen and methylene of carbonyl are respectively bridged with two palladium atoms to form an eight-membered ring.

2. A method for preparing an acetone coordinated binuclear palladium compound as claimed in claim 1, which comprises using fluoroacetylacetone or acetylacetone and palladium chloride as raw materials to synthesize a compound having two palladium atoms linked by acetone as a bridge under the condition of a mixed solution of aromatic hydrocarbon and acetone.

3. The acetone coordinated binuclear palladium compound as claimed in claim 1 is used as an industrial catalyst in a coupling reaction.