Beta-diimine zinc catalyst, and ligand, preparation method and application thereof

Abstract

The invention relates to a zinc complex of the formula (I), and a ligand, a preparation method and application thereof, wherein R1 to R6 and X are as defined herein. The zinc complex of the formula (I) can serve as a catalyst in catalysis of the ring-opening polymerization of lactide and caprolactone, and the activity of the catalyst can be subjected to 'off / on' regulation by Lewis acid and / or alkali.

Description

technical field

[0001] The invention relates to the field of polymer materials and catalysts, in particular to a β-diimine zinc catalyst and its ligand, preparation method and application. Background technique

[0002] In recent years, changing the catalytic performance of catalysts under external stimuli, thereby controlling the structure of polymerization products, has become a rapidly developing research field. Similar studies have been reported in existing literature, including electrochemically regulated acrylate radical polymerization; photochemically controlled anionic polymerization of ferrocenearene monomers; mechanochemically controlled ring-opening metathesis polymerization; redox-controlled caprolactone and lactide ring-opening (co)polymerization; and redox-controlled olefin polymerization, etc.

[0003] The redox-regulated ring-opening polymerization (ROP) of cyclic esters has been extensively studied [Chen CL. ACS Catal, 2018, 8:5506-5514]. In such systems, c...

Examples

Embodiment

[0061] The following examples illustrate different aspects of the invention and present data including the synthesis of ligands, the synthesis of metal complexes and their application to the ring-opening polymerization of lactide and caprolactone, wherein the synthesis of metal complexes, ring-opening The polymerization process is carried out under anhydrous and oxygen-free conditions. All sensitive substances are stored in a glove box refrigerator at -30°C. All solvents are strictly dried to remove water. Lactide is purified by recrystallization from dichloromethane and n-hexane. Caprolactone was obtained by drying calcium hydride for 12 hours and then purifying under reduced pressure. The zinc precursor zinc compound of bis(bistrimethylsilyl)amine was obtained according to the literature [Rivillo D, Gulyás H, Benet-Buchholz J, et al.Angewandte Chemie International Edition, 2007, 46(38): 7247-7250.] The synthesis was obtained, without special instructions, all the raw material...

Synthetic example 1

[0064] Synthesis Example 1: Synthesis of 2-((2,6-diisopropyl)amino)-3-cyano-4-((2,6-diisopropylphenyl)imino)-2-pentene

[0065]

[0066] Under nitrogen protection, add 2-((2,6-diisopropyl) amino)-4-((2,6-diisopropylphenyl) imino)-2-pentene ( 1.8 g, 4.3 mmol), and then 90 ml of tetrahydrofuran was added. After cooling the mixture solution to -78°C by liquid nitrogen / acetone, slowly add n-butyllithium (2.5 mol / L, 5.16 mmol, 2.06 ml) to the reaction system, react at -78°C for 5 minutes, and then Warm to room temperature for another 1 hour. After cooling down to -78°C again, p-toluenesulfonyl cyanide (0.82 g, 4.52 mmol) dissolved in 30 ml of tetrahydrofuran was added dropwise to the reaction system, and then warmed to room temperature for 10 hours. After the reaction is over, use a rotary evaporator to spin off the solvent, then dissolve the obtained solid with dichloromethane, and then extract the organic phase three times with saturated aqueous sodium chloride solution. After...

Synthetic example 2

[0071] Synthesis Example 2: 2-((2,6-diisopropyl)amino)-3-tert-butyryl-4-((2,6-diisopropylphenyl)imino)-2-pentene synthesis

[0072]

[0073] Under nitrogen protection, add 2-((2,6-diisopropyl) amino)-4-((2,6-diisopropylphenyl) imino)-2-pentene ( 4.18 g, 10 mmol), and then 100 ml of tetrahydrofuran was added. After cooling down to -78°C with liquid nitrogen / acetone, slowly add n-butyllithium (2.5 mol / L, 11.2 mmol, 4.5 ml) into the reaction system, react at -78°C for 5 minutes, then warm the reaction Allow to react for another 1 hour at room temperature. After cooling down to -78°C again, trimethylacetyl chloride (1.3 mL, 10.5 mmol) was added dropwise to the reaction system, and then warmed to room temperature for 12 hours. After the reaction was finished, spin off the solvent with a rotary evaporator, dissolve the solid with dichloromethane, and then extract three times with saturated aqueous sodium chloride solution. After the extraction, separate the organic phase with ...

technical field

[0001] The invention relates to the field of polymer materials and catalysts, in particular to a β-diimine zinc catalyst and its ligand, preparation method and application. Background technique

[0002] In recent years, changing the catalytic performance of catalysts under external stimuli, thereby controlling the structure of polymerization products, has become a rapidly developing research field. Similar studies have been reported in existing literature, including electrochemically regulated acrylate radical polymerization; photochemically controlled anionic polymerization of ferrocenearene monomers; mechanochemically controlled ring-opening metathesis polymerization; redox-controlled caprolactone and lactide ring-opening (co)polymerization; and redox-controlled olefin polymerization, etc.

[0003] The redox-regulated ring-opening polymerization (ROP) of cyclic esters has been extensively studied [Chen CL. ACS Catal, 2018, 8:5506-5514]. In such systems, c...

Examples

Embodiment

[0061] The following examples illustrate different aspects of the invention and present data including the synthesis of ligands, the synthesis of metal complexes and their application to the ring-opening polymerization of lactide and caprolactone, wherein the synthesis of metal complexes, ring-opening The polymerization process is carried out under anhydrous and oxygen-free conditions. All sensitive substances are stored in a glove box refrigerator at -30°C. All solvents are strictly dried to remove water. Lactide is purified by recrystallization from dichloromethane and n-hexane. Caprolactone was obtained by drying calcium hydride for 12 hours and then purifying under reduced pressure. The zinc precursor zinc compound of bis(bistrimethylsilyl)amine was obtained according to the literature [Rivillo D, Gulyás H, Benet-Buchholz J, et al.Angewandte Chemie International Edition, 2007, 46(38): 7247-7250.] The synthesis was obtained, without special instructions, all the raw material...

Synthetic example 1

[0064] Synthesis Example 1: Synthesis of 2-((2,6-diisopropyl)amino)-3-cyano-4-((2,6-diisopropylphenyl)imino)-2-pentene

[0065]

[0066] Under nitrogen protection, add 2-((2,6-diisopropyl) amino)-4-((2,6-diisopropylphenyl) imino)-2-pentene ( 1.8 g, 4.3 mmol), and then 90 ml of tetrahydrofuran was added. After cooling the mixture solution to -78°C by liquid nitrogen / acetone, slowly add n-butyllithium (2.5 mol / L, 5.16 mmol, 2.06 ml) to the reaction system, react at -78°C for 5 minutes, and then Warm to room temperature for another 1 hour. After cooling down to -78°C again, p-toluenesulfonyl cyanide (0.82 g, 4.52 mmol) dissolved in 30 ml of tetrahydrofuran was added dropwise to the reaction system, and then warmed to room temperature for 10 hours. After the reaction is over, use a rotary evaporator to spin off the solvent, then dissolve the obtained solid with dichloromethane, and then extract the organic phase three times with saturated aqueous sodium chloride solution. After...

Synthetic example 2

[0071] Synthesis Example 2: 2-((2,6-diisopropyl)amino)-3-tert-butyryl-4-((2,6-diisopropylphenyl)imino)-2-pentene synthesis

[0072]

[0073] Under nitrogen protection, add 2-((2,6-diisopropyl) amino)-4-((2,6-diisopropylphenyl) imino)-2-pentene ( 4.18 g, 10 mmol), and then 100 ml of tetrahydrofuran was added. After cooling down to -78°C with liquid nitrogen / acetone, slowly add n-butyllithium (2.5 mol / L, 11.2 mmol, 4.5 ml) into the reaction system, react at -78°C for 5 minutes, then warm the reaction Allow to react for another 1 hour at room temperature. After cooling down to -78°C again, trimethylacetyl chloride (1.3 mL, 10.5 mmol) was added dropwise to the reaction system, and then warmed to room temperature for 12 hours. After the reaction was finished, spin off the solvent with a rotary evaporator, dissolve the solid with dichloromethane, and then extract three times with saturated aqueous sodium chloride solution. After the extraction, separate the organic phase with ...

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