阅读说明：本技术 一种含（取代）吡唑环的氨基酚氧基锌络合物及其制备方法和应用 (Amino-phenol-oxygen-group zinc complex containing (substituted) pyrazole ring and preparation method and application thereof ) 是由 马海燕 王芳 于 2021-08-26 设计创作，主要内容包括：本发明公开了一类含(取代)吡唑环的氨基酚氧基锌络合物及其制备方法,以及其在高活性、高选择性催化内酯开环聚合中的应用。其制备方法包括如下步骤：将中性配体直接与金属原料化合物在有机介质中反应,然后经过滤、浓缩、重结晶步骤获得目标化合物。本发明的含(取代)吡唑环的氨基酚氧基锌络合物是一种高效的内酯开环聚合催化剂,可用于催化丙交酯等内酯的聚合反应；特别对于外消旋丙交酯可得到高等规度的聚丙交酯。本发明的含(取代)吡唑环的氨基酚氧基锌络合物优点十分明显：原料易得,合成路线简单,产物收率高,具有高催化活性和立体选择性,能获得高规整度、高分子量聚酯材料,能够满足工业部门的需要。其结构式如下所示。。(The invention discloses an aminophenol oxygen-based zinc complex containing (substituted) pyrazole rings, a preparation method thereof and application thereof in catalyzing ring-opening polymerization of lactones with high activity and high selectivity. The preparation method comprises the following steps: the neutral ligand directly reacts with the metal raw material compound in an organic medium, and then the target compound is obtained through the steps of filtering, concentrating and recrystallizing. The (substituted) pyrazole ring-containing aminophenoxy zinc complex is a high-efficiency lactone ring-opening polymerization catalyst and can be used for catalyzing the polymerization reaction of lactones such as lactide and the like; specially for treating diabetesWith respect to racemic lactide, a polylactide having a high isotacticity can be obtained. The (substituted) pyrazole ring-containing aminophenoxy zinc complex has obvious advantages: the raw materials are easy to obtain, the synthesis route is simple, the product yield is high, the catalyst activity and the stereoselectivity are high, the high-regularity and high-molecular-weight polyester material can be obtained, and the requirements of industrial departments can be met. The structural formula is shown as follows.)

1. An aminophenol ligand (I) containing a (substituted) pyrazole ring and a zinc metal complex (II) thereof, characterized by the general formula:

in the formulae (I), (II):

R¹～R²each represents hydrogen, C₁～C₂₀Alkyl of linear, branched or cyclic structure, C₇～C₃₀Mono-or poly-aryl substituted alkyl, halogen;

R³represents C₁～C₂₀Alkyl of linear, branched or cyclic structure, C₇～C₃₀Mono-or polyaryl-substituted alkyl, C₆～C₁₈Aryl of (a);

a is a group of formula (III) or (IV):

x represents an amino group NR⁴R⁵Wherein R is⁴～R⁵Are respectively C₁～C₆Alkyl of linear, branched or cyclic structure, trimethylsilyl, triethylsilyl, dimethylhydrosilyl, R⁴And R⁵May be the same or different.

2. The (substituted) pyrazole ring-containing aminophenol ligands (I) and their metal zinc complexes (II) according to claim 1, wherein R is¹～R²Preferably hydrogen, C₁～C₈Alkyl of linear, branched or cyclic structure, C₇～C₂₀Mono-or poly-aryl substituted alkyl, halogen; r³Preferably C₁～C₈Alkyl of linear, branched or cyclic structure, C₇～C₂₀Mono-or polyaryl-substituted alkyl, C₆～C₁₂Aryl of (a); x is preferably di (trimethylsilyl) amino, di (triethylsilyl) amino or di (dimethylhydrosilyl) amino.

3. The (substituted) pyrazole ring-containing aminophenol ligands (I) and their metal zinc complexes (II) according to claim 1, wherein R is¹～R²Preferably hydrogen, methyl, isopropyl, tert-butyl, cumyl, trityl or halogen; r³Preferably methyl, ethyl, isopropyl, n-butyl, tert-butyl, cyclopentyl, n-hexyl, cyclohexyl, n-octyl, cyclooctyl, benzyl, phenethyl; x is preferably a bis (trimethylsilyl) amino group.

4. The method for preparing the (substituted) pyrazole ring-containing aminophenol ligand (I) and the metal zinc complex (II) thereof according to any one of claims 1 to 3, comprising the steps of:

reacting 1- (2-bromoethyl) -3, 5-dimethylpyrazole or 1- (2-bromoethyl) pyrazole with primary amine to generate corresponding secondary amine, adding 2-bromomethyl-4, 6-disubstituted phenol (V), reacting at 25-150 ℃ for 2-72 hours, and collecting a ligand compound (I) from a reaction product;

optionally, reacting the (substituted) pyrazole ring-containing aminophenol ligand compound shown in the formula (I) with a zinc metal raw material compound in an organic medium at the reaction temperature of 0-100 ℃ for 2-96 hours, and collecting an (substituted) pyrazole ring-containing aminophenoxy zinc target compound (II) from the reaction product;

substituent R in the above preparation method¹～R³And A is in accordance with each corresponding group of the (substituted) pyrazole ring-containing aminophenol ligand (I) and the metal zinc complex thereof (II) according to any one of claims 1 to 3;

the zinc metal raw material compound has a general formula of ZnX₂And X is identical with the corresponding group of the (substituted) pyrazole ring-containing aminophenoxy zinc complex (II) according to any one of claims 1 to 3.

5. The method according to claim 4, wherein the zinc metal raw material compound is bis { di (trimethylsilyl) amino } zinc, and the molar ratio of the aminophenol ligand compound containing a (substituted) pyrazole ring to the metal raw material compound is 1:1 to 1.5; the organic medium is one or two of tetrahydrofuran, diethyl ether, toluene, benzene, petroleum ether and n-hexane.

6. Use of the (substituted) pyrazole ring-containing aminophenoxy zinc complex according to any one of claims 1 to 3, for ring-opening polymerization of a lactone.

7. Use according to claim 6, characterized in that the lactone is selected from the group consisting of L-lactide, D-lactide, rac-lactide, meso-lactide, epsilon-caprolactone, beta-butyrolactone, alpha-methyltrimethylene cyclic carbonate.

8. Use according to claim 6, characterized in that lactide is polymerized with the (substituted) pyrazole ring-containing amino phenol oxy zinc complex as a catalyst according to any of claims 1 to 3, the molar ratio of catalyst to monomer in the polymerization being 1:1 to 10000.

9. The use according to claim 6, wherein lactide is polymerized in the presence of alcohol using the (substituted) pyrazole ring-containing aminophenoxy zinc complex as a catalyst according to any one of claims 1 to 3, wherein the molar ratio of the catalyst to the alcohol and the monomer is 1:1 to 50:1 to 10000; the alcohol is C₁～C₁₀Alkyl alcohols of linear, branched or cyclic structure, C₇～C₂₀Mono-or poly-aryl substituted alkyl alcohols.

10. The use according to claim 6, characterized in that epsilon-caprolactone is polymerized with or without the addition of alcohol in the presence of the (substituted) pyrazole ring-containing zinc aminophenoxy complex according to any one of claims 1 to 3 as a catalyst; the alcohol is C₁～C₁₀Alkyl alcohols of linear, branched or cyclic structure, C₇～C₂₀Mono-or poly-aryl substituted alkyl alcohols.

Technical Field

The invention relates to an aminophenol oxygen group zinc complex containing (substituted) pyrazole ring and application of the complex in lactone polymerization.

Background

The traditional polyolefin plastic is derived from micromolecular olefin generated by petroleum catalytic cracking, the petroleum resource exploitation is exhausted due to the continuous synthesis of a large amount of the traditional polyolefin plastic, and white pollution in the global range is caused because the polyolefin plastic is not degraded under common environmental conditions. The aliphatic polyester material has the advantages of degradability, biocompatibility and the like, wherein polylactic acid as a novel green material has the advantages, and simultaneously, the lactic acid serving as a raw material of the aliphatic polyester material can be obtained by fermenting waste materials such as corn straws and kitchen waste through microorganisms, so that the aliphatic polyester material is free from dependence on petroleum from the source. In addition, polylactide has mechanical properties and thermal stability comparable to those of polyolefins, and can be applied to the fields of food packaging including disposable straws, tableware for children, textiles, automobiles, and the like. Because of the above advantages of polylactide, how to synthesize a polymer with excellent properties and expand the polymer to an industrial production scale is a problem that scientists in the related art continuously try to overcome. Among them, lactide is obtained by lactic acid dimerization, and then ring opening polymerization is performed by the lactide under the action of a catalyst, so that polylactide having a high molecular weight can be obtained under mild conditions, and thus the method attracts wide attention.

The lactide has three isomers, namely levo-lactide (L-LA), dextro-lactide (D-LA) and meso-lactide (meso-LA), and racemic lactide (rac-LA) is obtained by mixing L-LA and D-LA in equal proportion. The ring opening polymerization of the lactides with different steric configurations under the action of different catalysts can obtain the polylactides with different chain sequences. The ring-opening polymerization of single levorotatory lactide can obtain isotactic poly-levorotatory lactide (PLLA), on the contrary, the ring-opening polymerization of single dextrorotatory lactide can obtain isotactic poly-dextrorotatory lactide (PDLA), the ring-opening polymerization of meso-lactide and racemic lactide can obtain atactic polylactide and hetero-polylactide, while meso-lactide can uniquely obtain syndiotactic polylactide and racemic lactide can uniquely obtain isotactic stereoblock polylactide. The isotactic stereoblock polymer obtained from rac-LA has high glass transition temperature and melting point, and rac-LA has low cost and meets the requirement of industrial production. The zinc complex compound has high activity in catalyzing rac-LA polymerization generally, zinc is an essential trace element in a human body, the metal catalyst has certain biocompatibility, and the metal catalyst has no harm even if a small amount of metal residues exist in the polymer. In addition, the zinc catalyst is close to white in the processing process, so that the process of decolorization is avoided. Therefore, designing a metal zinc catalyst with a specific structure to realize controllable polymerization with high activity and high isotactic selectivity on rac-LA so as to obtain isotactic stereoblock PLA with excellent performance is one of the current research hotspots.

In 1999, the Coates group utilized for the first time β -diimine binuclear zinc complex (BDI) Zn (O)ⁱPr) as catalyst to catalyze the polymerization of racemic lactide to obtain high-hetero-regular polylactide (P)_r0.90) (j.am. chem. soc.,1999,121, 11583-. Subsequently, the Chisholm group synthesized the beta-diimine mononuclear zinc complex (BDI) Zn (THF) (OSIPh)₃) The catalytic racemic lactide polymerization shows high heteroleptic selectivity (P)_r>0.90) (j.chem.soc., dalton. trans.,2001,3, 222-. In 2003, the Williams group synthesized dinuclear zinc complexes of monoethoxy-bridged aminophenol ligands, which had high catalytic activity for the ring-opening polymerization of racemic lactide, but no stereoselectivity (j.am.chem.soc.,2003,125, 11350-11359). The same year Chisholm group reported zinc complexes of asymmetric biphenyldiphenol ligands, with lower catalytic activity for racemic lactide, yielding only partially hetero-regular polymers (Dalton. trans.,2003,3, 406-one 412). In 2005, the Lin group synthesized iminophenoxide binuclear zinc complexes of cyclohexylidene skeleton, which were less active in racemic lactide polymerization and showed only low heteroleptic selectivity (P)_r0.75) (Polymer,2005,46, 9784-. In 2009, the group reported [ NNO ]]The zinc complex of the tridentate ketoimine ligand shows higher catalytic activity on the polymerization of the racemic lactide, but only shows a certain heterotactic tendency (P)_r0.61) (j.poly.sci., a: poly.chem.2009, 47, 2318-. In 2010, we reported that multidentate aminophenoxy zinc complexes have higher catalytic activity for the ring-opening polymerization of racemic lactide, but only resulted in polymers with an isotactic trend (Dalton trans, 2010,39, 7897-.

To achieve isotactic selectivity, researchers attempted to introduce chiral factors on the ligand backbone of the complex, as in 2009, the Mehrkhodavandi topic combined into chiral cyclohexylidene-bridged tridentate aminophenoxy zinc complexes, which are racemicLactide is catalytically active but not stereoselective (Organometallics,2009,28, 1309-1319). In 2013, the Honrado group reported that cyclopentadienyl-containing chiral heteroscorpion zinc complexes, although less active in catalyzing the polymerization of racemic lactide, gave moderately isotactic polymers (P)_m0.77) (Organometallics,2013,32, 3437-. In the same year, the group introduces a pyrrolidine structure on a ligand framework to synthesize a series of chiral amino phenol zinc oxide complexes, catalyzes ring-opening polymerization of racemic lactide, and obtains higher activity and higher isotactic selectivity (P) for the first time_m0.84) (chem. commun.,2013, 49, 8686-. Du group reported a series of chiral oxazoline-substituted beta-diimine ligand zinc complexes in 2014, and the zinc complexes have low catalytic activity on racemic lactide polymerization and have certain catalytic activity under high-temperature conditions, so that the isotacticity P is obtained_mMulti-block isotactic polylactide (ACS Macro lett.,2014,3,689-692) of 0.77-0.91. A2016 Kol group synthesizes achiral ethylene bridged zinc complex to catalyze ring-opening polymerization of racemic lactide, and obtains higher activity and medium isotactic selectivity (P)_m0.81) (chem. eur. j.,2016,22: 11533-. The Honrado group reported in 2019 that [ NNN ] is chiral]The tridentate heteroscorpion zinc complex has lower activity for catalyzing racemic lactide compared with the heteroscorpion zinc complex reported before, but the isotactic selectivity is improved (P)_m＝0.88)(Chem.Commun.,2019, 55:8947-8950)。

Over twenty years since 1999 to date, the search for metal catalyst structures that can achieve highly active and highly isotactic selective polymerization of racemic lactide has continued. However, in general, the high activity and the high isotactic selectivity of the catalyst are difficult to be obtained at the same time, so that only a few cases of catalysts with high activity and high isotactic selectivity have been reported so far, and the catalytic effect has a large promotion space. Therefore, the design and synthesis of the metal zinc catalyst with a specific structure to realize the controllable polymerization of the racemic lactide with high activity and high isotactic selectivity has important significance for improving the technical level of the field.

Disclosure of Invention

The invention aims to disclose an aminophenol ligand containing (substituted) pyrazole ring and a zinc complex thereof.

The invention also discloses a preparation method of aminophenol ligand containing (substituted) pyrazole ring and zinc complex thereof.

The invention also aims to disclose application of aminophenol ligands containing (substituted) pyrazole rings and zinc complexes thereof as catalysts in lactone polymerization.

The technical idea of the invention is as follows:

the amino phenol ligand has easily obtained raw materials, simple and convenient synthesis and adjustable structure. The zinc complex catalyst obtained by reacting the aminophenol ligand with the zinc metal raw material compound is applied to the ring-opening polymerization research of racemic lactide, and the electronic effect and the steric hindrance effect of a metal center can be conveniently adjusted by changing substituent groups at all positions of the ligand, so that the adjustment of the catalytic performance of the complex is realized. The invention introduces a pyrazole ring with a plane structure in an aminophenoxy ligand structure through ethylene bridging, and after the pyrazole ring is coordinated with a metal center, a combined skeleton nitrogen atom forms a hexahydric chelate ring with a more crowded space structure, so that a space coordination environment which is favorable for realizing the high-stereoselectivity polymerization of racemic lactide is hopefully constructed. Meanwhile, after the N atom on the pyrazole ring is coordinated with the metal center, the substituent on the adjacent carbon atom of the nitrogen atom has direct influence on the coordination environment of the metal center, so that the 3, 5-position substituent of the pendant pyrazole ring on the ligand is adjusted, and the spatial structure around the metal can be finely adjusted. In addition, the steric hindrance and Lewis acidity of the metal center are adjusted by changing the electronic effect and the steric hindrance effect of the substituent on the ligand framework, so that the metal zinc catalyst with high activity and high isotactic selectivity is obtained.

The invention provides an aminophenol ligand (I) containing a (substituted) pyrazole ring and a metal zinc complex (II) thereof, which are characterized by having the following general formula:

in the formulae (I), (II):

R¹～R²each represents hydrogen, C₁～C₂₀Alkyl of linear, branched or cyclic structure, C₇～C₃₀Mono-or poly-aryl substituted alkyl, halogen;

R³represents C₁～C₂₀Alkyl of linear, branched or cyclic structure, C₇～C₃₀Mono-or polyaryl-substituted alkyl, C₆～C₁₈Aryl of (a);

a is a group of formula (III) or (IV):

x represents an amino group NR⁴R⁵Wherein R is⁴～R⁵Are respectively C₁～C₆Alkyl of linear, branched or cyclic structure, trimethylsilyl, triethylsilyl, dimethylhydrosilyl, R⁴And R⁵May be the same or different.

More characterized in that in the formulae (I) and (II), R¹～R²Preferably hydrogen, C₁～C₈Alkyl of linear, branched or cyclic structure, C₇～C₂₀Mono-or poly-aryl substituted alkyl, halogen;

R³preferably C₁～C₈Alkyl of linear, branched or cyclic structure, C₇～C₂₀Mono-or polyaryl-substituted alkyl, C₆～C₁₂Aryl of (a);

x is preferably di (trimethylsilyl) amino, di (triethylsilyl) amino or di (dimethylhydrosilyl) amino.

In the formulae (I), (II), R¹～R²Preferably hydrogen, methyl, isopropyl, tert-butyl, cumyl, trityl or halogen; r³Preferably methyl, ethyl, isopropyl, n-butyl, tert-butyl, cyclopentyl, n-hexyl, cyclohexyl, n-octyl, cyclooctyl, benzyl, phenethyl; x is preferably a bis (trimethylsilyl) amino group.

Preferred (substituted) pyrazole ring-containing aminophenol ligands have the following structural formula:

preferred (substituted) pyrazole ring-containing aminophenoxy zinc complexes are of the structure:

the preparation method of the (substituted) pyrazole ring-containing aminophenol ligand (I) and the zinc complex (II) thereof is as follows:

reacting 1- (2-bromoethyl) -3, 5-dimethylpyrazole or 1- (2-bromoethyl) pyrazole with primary amine to generate corresponding secondary amine, adding 2-bromomethyl-4, 6-disubstituted phenol (V), reacting at 25-150 ℃ for 2-72 hours, and collecting a ligand compound (I) from a reaction product;

optionally, reacting the (substituted) pyrazole ring-containing aminophenol ligand compound shown in the formula (I) with a zinc metal raw material compound in an organic medium at the reaction temperature of 0-100 ℃ for 2-96 hours, and collecting an (substituted) pyrazole ring-containing aminophenoxy zinc target compound (II) from the reaction product;

substituent R in the above preparation method¹～R³And A and the respective corresponding groups satisfying the aforementioned aminophenol ligand (I) containing a (substituted) pyrazole ring and its metal zinc complex (II)The consistency is achieved;

the zinc metal raw material compound has a general formula of ZnX₂X is identical with the corresponding group of the aminophenoxy zinc complex (II) containing a (substituted) pyrazole ring as described previously;

the zinc metal starting compound is preferably bis { bis (trimethylsilyl) amino } zinc.

The molar ratio of the (substituted) pyrazole ring-containing aminophenol ligand compound (I) to the zinc metal raw material compound is 1: 1-1.5; the organic medium is one or two of tetrahydrofuran, diethyl ether, toluene, benzene, petroleum ether and n-hexane.

In the preparation method of the (substituted) pyrazole ring-containing aminophenol ligand (I), the synthesis of 1- (2-bromoethyl) -3, 5-dimethylpyrazole and 1- (2-bromoethyl) pyrazole can be carried out according to the following routes by the methods of reference literature:

wherein, sodium hydroxide solid is dissolved in water and slowly dripped into a mixed solution of 3, 5-dimethylpyrazole, 1, 2-dibromoethane and tetrabutylammonium bromide, and the target compound 1- (2-bromoethyl) -3, 5-dimethylpyrazole is obtained through heating reflux reaction (org. biomol. chem.,2011,9, 2992-one 2998).

After dissolving the sodium hydroxide solid in water, slowly dropping the sodium hydroxide solid into a mixed solution of pyrazole, 1, 2-dibromoethane and tetrabutylammonium bromide, and heating and refluxing the mixed solution to react to obtain the target compound 1- (2-bromoethyl) pyrazole (Dalton Trans.,2003,21, 4181-4191).

In the preparation method of the (substituted) pyrazole ring-containing aminophenol ligand (I), 2-bromomethyl-4, 6-disubstituted phenol shown in the formula (V) can be synthesized by a reference method according to the following route, wherein the 2, 4-substituted phenol is reacted with paraformaldehyde in a 33% hydrogen bromide acetic acid solution (Inorg. chem.,2002,41, 3656; J.org. chem.,1994,59, 1939):

the zinc complex containing the (substituted) pyrazole ring aminophenol ligand is a high-efficiency lactone polymerization catalyst, can be used for the polymerization reaction of L-lactide, D-lactide, rac-lactide, meso-lactide, epsilon-caprolactone, beta-butyrolactone and alpha-methyltrimethylene cyclic carbonate, and adopts solution polymerization and melt polymerization.

The (substituted) pyrazole ring-containing aminophenoxy zinc complex is used as a catalyst to polymerize lactide at the temperature of-40 to 140 ℃, preferably-40 to 110 ℃; the molar ratio of the catalyst to the monomer during polymerization is 1: 1-10000, preferably 1: 100-5000.

The (substituted) pyrazole ring-containing aminophenoxy zinc complex is used as a catalyst, and lactide is polymerized at the temperature of-40 to 140 ℃ in the presence of alcohol, preferably at the temperature of-40 to 110 ℃; the molar ratio of the catalyst to the alcohol to the monomer during polymerization is 1: 1-50: 1-10000, preferably 1: 1-50: 100-5000; the alcohol is C₁～C₁₀Alkyl alcohols of linear, branched or cyclic structure, C₇～C₂₀The mono-or poly-aryl substituted alkyl alcohol of (a).

The (substituted) pyrazole ring-containing aminophenoxy zinc complex is used as a catalyst, epsilon-caprolactone is polymerized under the condition of adding alcohol or not adding alcohol, and the molar ratio of the catalyst to the alcohol to a monomer during polymerization is 1: 0-50: 1-10000, preferably 1: 0-50: 100-5000; the alcohol is C₁～C₁₀Alkyl alcohols of linear, branched or cyclic structure, C₇～C₂₀The mono-or poly-aryl substituted alkyl alcohol of (a).

The catalyst provided by the invention has the advantages of easily available ligand raw materials, convenient preparation, higher catalytic activity and high stereoselectivity, is easy to obtain high molecular weight polylactone, and has wide application prospect. The invention is further illustrated, but not limited, by the following examples.

Detailed Description

Example 1

Synthesis of ligand L1:

(1) synthesis of N- [2- (3, 5-dimethyl-pyrazol-1-yl) ethyl ] N-hexylamine

Under the protection of inert gas, N-hexylamine (22.4g, 222mmol) and anhydrous potassium carbonate (3.37g, 24.4mmol) are added into a three-neck flask, and a solution of 1- (2-bromoethyl) -3, 5-dimethylpyrazole (4.50g, 22.2mmol) in 15mL of N, N-dimethylformamide is added and reacted at room temperature overnight. The reaction was quenched with water, extracted with ethyl acetate, the organic phases combined, washed, dried, filtered and the filtrate concentrated to dryness to give a yellow viscous liquid (4.50g, 90.8% yield, purity about 80%). Directly used for the next step of ligand synthesis.

(2) Synthesis of ligand L1

N- [2- (3, 5-dimethyl-pyrazol-1-yl) ethyl ] N-hexylamine (4.50g, purity about 80%, about 16.2mmol) was added to a 100mL single-necked flask, anhydrous potassium carbonate (2.46g, 17.8mmol) and 30mL of DMF were added, and the mixture was stirred well for 1 h. 2-bromomethyl-4-methyl-6-tritylphenol (7.54g, 17.0mmol) was added and reacted at room temperature overnight. Adding water to quench reaction, adding dichloromethane to extract for 3 times, combining organic phases, washing, drying, filtering, and spin-drying the filtrate to obtain a crude product. Purification by column chromatography gave a white foamy solid (3.32g, 34.3%).

¹H NMR(CDCl₃,400MHz,298K):δ10.15(br,s,1H,OH),7.25–7.15(m,12H,ArH),7.15– 7.07(m,3H,ArH),6.92(s,1H,ArH),6.74(s,1H,ArH),5.68(s,1H,Pyrazolyl-H),3.66(s,2H, ArCH₂N),3.62(t,³J＝6.9Hz,2H,Pyrazolyl-CH₂CH₂),2.73(t,³J＝6.9Hz,2H, Pyrazolyl-CH₂CH₂),2.23(t,³J＝7.6Hz,2H,NCH₂ of n-hexyl),2.17(s,6H,ArCH₃ and Pyrazolyl-CH₃),1.91(s,3H,Pyrazolyl-CH₃),1.32–1.20(m,4H,CH₂ of n-hexyl),1.20-1.11(m,2H, CH₂ of n-hexyl),1.07-0.90(m,2H,CH₂ of n-hexyl),0.86(t,³J＝6.8Hz,3H,CH₃ of n-hexyl).¹³C {¹H}NMR(CDCl₃,100MHz,298K):δ154.1,147.6,146.1,139.0,134.0,131.2,128.6,127.1, 126.9,125.4,122.4,105.1,105.0(all Ar-C and Pyrazolyl-C),63.3(CPh₃),59.1(ArCH₂N),54.5 (NCH₂),52.6(NCH₂CH₂Py),46.2(NCH₂CH₂Py),31.8(CH₂ of n-hexyl),27.0(CH₂ of n-hexyl), 26.2(CH₂ of n-hexyl),22.7(CH₂ of n-hexyl),21.2(ArCH₃),14.2(CH₃ of n-hexyl),13.6 (Pyrazolyl-CH₃),11.0(Pyrazolyl-CH₃).Anal.Calcd.for C₄₀H₄₇N₃O:C,82.01；H,8.09；N,7.17. Found:C,82.08；H,8.01；N,7.11％.

Example 2

Synthesis of ligand L2

(1) Synthesis of N- [2- (3, 5-dimethyl-pyrazol-1-yl) ethyl ] cyclohexylamine

The procedure is as in example 1 except that cyclohexylamine (10.5g, 106mmol), potassium carbonate (3.22g, 23.3mmol) and 1- (2-bromoethyl) -3, 5-dimethylpyrazole (4.31g, 21.2mmol) are used as starting materials. A pale yellow viscous liquid was obtained (4.46g, crude yield 95.0%, purity about 80%).

(2) Synthesis of ligand L2

The procedure was as in example 1 except for using N- [2- (3, 5-dimethyl-pyrazol-1-yl) ethyl ] cyclohexylamine (4.46g, purity about 80%, about 16.1mmol), anhydrous potassium carbonate (2.67g, 19.3mmol) and 2-bromomethyl-4-methyl-6-tritylphenol (7.14g, 16.1mmol) as starting materials. Purification by column chromatography gave a white solid (4.13g, 43.9%).

¹H NMR(CDCl₃,400MHz,298K):δ10.21(br s,1H,OH),7.22(d,³J＝8.0Hz,6H,ArH), 7.17(t,³J＝8.0Hz,6H,ArH),7.10(t,³J＝7.0Hz,3H,ArH),6.94(d,⁴J＝1.7Hz,1H,ArH),6.75 (d,⁴J＝1.5Hz,1H,ArH),5.65(s,1H,Pyrazolyl-H),3.74(s,2H,ArCH₂N),3.40(t,³J＝7.6Hz,2H, Pyrazolyl-CH₂CH₂),2.67(t,³J＝7.6Hz,2H,Pyrazolyl-CH₂CH₂),2.29-2.18(m,1H,CH of cyclohexyl),2.17(s,3H,ArCH₃),2.16(s,3H,Pyrazolyl-CH₃),1.80(s,3H,Pyrazolyl-CH₃),1.70 (br d,³J＝10.6Hz,2H,CH₂ of cyclohexyl),1.65-1.50(m,3H,CH₂of cyclohexyl),1.20-0.92(m, 5H,CH₂ of cyclohexyl).¹³C{¹H}NMR(CDCl₃,100MHz,298K):δ154.1,147.4,145.9,138.9, 133.9,131.1,128.5,127.0,126.9,125.3,122.7,104.81,104.75(all Ar-C and Pyrazolyl-C),63.2 (CPh₃),60.2(ArCH₂N),55.7(NCH),49.4(Pyrazolyl-CH₂CH₂N),47.5(Pyrazolyl-CH₂CH₂N),27.8 (CH₂ of cyclohexyl),26.0(CH₂ of cyclohexyl),25.8(CH₂ of cyclohexyl),21.0(ArCH₃),13.5 (Pyrazolyl-CH₃),10.8(Pyrazolyl-CH₃).Anal.Calcd.for C₄₀H₄₅N₃O:C,82.29；H,7.77；N,7.20. Found:C,82.46；H,7.93；N,6.94％.

Example 3

Synthesis of ligand L3

(1) Synthesis of N- [2- (3, 5-dimethyl-pyrazol-1-yl) ethyl ] benzylamine

The procedure was as in example 1 except for using benzylamine (21.2g, 198mmol), potassium carbonate (6.01g, 43.5mmol) and 1- (2-bromoethyl) -3, 5-dimethylpyrazole (8.02g, 39.5mmol) as starting materials. A pale yellow viscous liquid was obtained (8.59g, crude yield 93.6%, purity about 80%).

(2) Synthesis of ligand L3

The procedure was as in example 1 except for using N- [2- (3, 5-dimethyl-pyrazol-1-yl) ethyl ] benzylamine (8.59g, purity about 80%, about 30.0mmol), anhydrous potassium carbonate (4.98g, 36.0mmol) and 2-bromomethyl-4-methyl-6-tritylphenol (13.3g, 30.0mmol) as starting materials. Purification by column chromatography gave a white solid (8.37g, 47.2%).

¹H NMR(CDCl₃,400MHz,298K):δ10.00(s,1H,OH),7.25–7.11(m,18H,ArH),6.92(d, ⁴J＝1.6Hz,1H,ArH),6.86–6.72(m,3H,ArH),5.65(s,1H,Pyrazolyl-H),3.75(s,2H,ArCH₂N), 3.73(t,³J＝7.0Hz,2H,Pyrazolyl-CH₂),3.31(s,2H,PhCH₂N),2.70(t,³J＝7.0Hz,2H, Pyrazolyl-CH₂CH₂),2.18(s,3H,ArCH₃),2.11(s,3H,Pyrazolyl-CH₃),1.79(s,3H,Pyrazolyl-CH₃). ¹³C{¹H}NMR(CDCl₃,100MHz,298K):δ153.7,147.6,146.1,139.0,136.8,134.1,131.3,131.2, 129.8,129.1,128.5,127.5,127.2,127.1,125.5,122.2,105.2,105.1(all Ar-C and Pyrazolyl-C), 63.3(CPh₃),59.1(ArCH₂N),58.2(PhCH₂N),52.3(Pyrazolyl-CH₂CH₂N),46.1 (Pyrazolyl-CH₂CH₂N),21.0(ArCH₃),13.5(Pyrazolyl-CH₃),10.8(Pyrazolyl-CH₃).Anal.Calcd.for C₄₁H₄₁N₃O:C,83.21；H,6.98；N,7.10.Found:C,83.24；H,7.05；N,7.04％.

Example 4

Synthesis of ligand L4

(1) Synthesis of N- [2- (3, 5-dimethyl-pyrazol-1-yl) ethyl ] phenethylamine

The procedure is as in example 1 except that phenethylamine (31.9g, 263mmol), potassium carbonate (8.00g, 57.9mmol) and 1- (2-bromoethyl) -3, 5-dimethylpyrazole (10.7g, 52.6mmol) are used as starting materials. A pale yellow viscous liquid was obtained (12.5g, crude yield 95.1%, purity about 80%).

(2) Synthesis of ligand L4

The procedure is as in example 1 except that N- [2- (3, 5-dimethyl-pyrazol-1-yl) ethyl ] phenethylamine (12.5g, purity about 80%, about 40.0mmol), anhydrous potassium carbonate (6.63g, 48.0mmol) and 2-bromomethyl-4-methyl-6-tritylphenol (17.7g, 40.0mmol) are used as starting materials. Purification by column chromatography gave a white solid (13.5g, 55.7%).

¹H NMR(CDCl₃,400MHz,298K):δ9.87(br s,1H,OH),7.26–7.15(m,15H,ArH),7.12(t, ³J＝6.8Hz,3H,ArH),7.01-6.93(m,3H,ArH),6.76(s,1H,ArH),5.69(s,1H,Pyrazolyl-H),3.74 (s,2H,ArCH₂N),3.62(t,³J＝6.9Hz,2H,Pyrazolyl-CH₂CH₂),2.82(t,³J＝6.9Hz,2H, NCH₂CH₂Ph),2.57–2.42(m,4H,NCH₂CH₂Ph and Pyrazolyl-CH₂CH₂N),2.18(s,3H,ArCH₃), 2.17(s,3H,Pyrazolyl-CH₃),1.89(s,3H,Pyrazolyl-CH₃).¹³C{¹H}NMR(CDCl₃,100MHz,298 K):δ153.9,147.6,145.9,139.2,139.0,134.0,131.1,130.90,130.86,128.7,128.4,127.0,126.2, 125.4,122.2,105.1,105.0(all Ar-C and Pyrazolyl-C),63.2(CPh₃),59.0(ArCH₂N),56.1 (Ph-CH₂CH₂N),52.7(Pyrazolyl-CH₂CH₂N),46.2(Pyrazolyl-CH₂CH₂N),32.6(NCH₂CH₂Ph),21.0 (ArCH₃),13.5(Pyrazolyl-CH₃),11.0(Pyrazolyl-CH₃).Anal.Calcd.for C₄₂H₄₃N₃O:C,83.27；H, 7.15；N,6.94.Found:C,83.26；H,7.15；N,6.85％.

Example 5

Synthesis of ligand L5:

(1) synthesis of N- [2- (pyrazol-1-yl) ethyl ] N-hexylamine

The procedure is as in example 1 except that n-hexylamine (24.5g, 242mmol), potassium carbonate (7.37g, 53.4mmol) and 1- (2-bromoethyl) pyrazole (8.44g, 48.5mmol) are used as starting materials. A pale yellow viscous liquid was obtained (9.00g, crude yield 94.9%, purity about 80%).

(2) Synthesis of ligand L5

The procedure is as in example 1 except that N- [2- (pyrazol-1-yl) ethyl ] N-hexylamine (9.00g, purity about 80%, about 36.8mmol), anhydrous potassium carbonate (6.11g, 44.2mmol) and 2-bromomethyl-4-methyl-6-tritylphenol (16.3g, 36.8mmol) are used as starting materials. Purification by column chromatography gave a white solid (14.0g, 68.1%).

¹H NMR(CDCl₃,400MHz,298K):δ10.32(br s,1H,OH),7.45(d,³J＝2.0Hz,1H, Pyrazolyl-H),7.25–7.18(m,12H,ArH),7.17–7.10(m,3H,ArH),6.96(d,³J＝2.0Hz,1H, Pyrazoly-H),6.94(d,⁴J＝1.4Hz,1H,ArH),6.74(d,⁴J＝1.4Hz,1H,ArH),6.10(t,³J＝2.0Hz,1H, Pyrazolyl-H),3.63(t,³J＝6.4Hz,2H,Pyrazolyl-CH₂CH₂),3.61(s,2H,ArCH₂N),2.75(t,³J＝6.5 Hz,2H,Pyrazolyl-CH₂CH₂),2.18(s,3H,ArCH₃),2.15-2.08(m,2H,NCH₂ of n-hexyl),1.28–1.18 (m,4H,CH₂ of n-hexyl),1.17-1.11(m,2H,CH₂ of n-hexyl),1.07-0.95(m,2H,CH₂ of n-hexyl), 0.85(t,³J＝7.1Hz,3H,CH₃ of n-hexyl).¹³C{1H}NMR(CDCl₃,100MHz,298K):δ153.9, 146.0,139.63,139.60,134.0,131.1,130.7,130.3,128.7,127.0,126.9,125.4,122.2,105.1(all Ar-C and Pyrazolyl-C),63.2(CPh₃),58.9(ArCH₂N),54.9(NCH₂),52.7(Pyrazolyl-CH₂CH₂N),50.4 (Pyrazolyl-CH₂CH₂N),31.6(CH₂ of n-hexyl),26.8(CH₂ of n-hexyl),25.9(CH₂ of n-hexyl),22.5 (CH₂ of n-hexyl),21.0(ArCH₃),20.9,14.0(CH₃ of n-hexyl).Anal.Calcd.for C₃₈H₄₃N₃O:C,81.83； H,7.77；N,7.53.Found:C,81.66；H,7.80；N,7.43％.

Example 6

Synthesis of ligand L6:

(1) synthesis of N- [2- (pyrazol-1-yl) ethyl ] cyclohexylamine

The procedure is as in example 1, except that cyclohexylamine (21.4g, 216mmol), potassium carbonate (6.55g, 47.4mmol) and 1- (2-bromoethyl) pyrazole (7.50g, 43.1mmol) are used as starting materials. A pale yellow viscous liquid was obtained (7.51g, crude yield 90.0%, purity about 80%).

(2) Synthesis of ligand L6

The procedure was as in example 1 except for using N- [2- (pyrazol-1-yl) ethyl ] cyclohexylamine (7.51g, purity: 80%, ca. 31.1mmol), anhydrous potassium carbonate (5.16g, 37.3mmol) and 2-bromomethyl-4-methyl-6-tritylphenol (13.8g, 31.1mmol) as starting materials. Purification by column chromatography gave a white solid (11.4g, 65.9%).

¹H NMR(CDCl₃,400MHz,298K):δ10.52(br s,1H,OH),7.44(d,³J＝1.9Hz,1H, Pyrazolyl-H),7.24–7.17(m,12H,ArH),7.16-7.09(m,3H,ArH),6.94(s,1H,ArH),6.86(d,³J＝ 1.9Hz,1H,Pyrazolyl-H),6.74(s,1H,ArH),6.04(t,³J＝1.9Hz,1H,Pyrazolyl-H),3.65(s,2H, ArCH₂N),3.53(t,³J＝6.1Hz,2H,Pyrazolyl-CH₂CH₂),2.77(t,³J＝6.1Hz,2H, Pyrazolyl-CH₂CH₂),2.18(s,3H,ArCH₃),1.91(br t,³J＝10.5Hz,1H,CH of cyclohexyl),1.67(br d,³J＝7.3Hz,2H,CH₂ of cyclohexyl),1.59-1.44(m,3H,CH₂ of cyclohexyl),1.17–0.86(m,5H, CH₂ of cyclohexyl).¹³C{¹H}NMR(CDCl₃,100MHz,298K):154.1,146.0,139.70,139.66,133.9, 131.2,130.7,128.6,127.0,126.8,125.4,122.4,104.8(all Ar-C and Pyrazolyl-C),63.2(CPh₃),60.3 (ArCH₂N),54.9(NCH),51.6(Pyrazolyl-CH₂CH₂N),49.9(Pyrazolyl-CH₂CH₂N),27.6(CH₂ of cyclohexyl),25.7(CH₂ of cyclohexyl),21.0(ArCH₃),21.0(CH₂ of cyclohexyl).Anal.Calcd.for C₃₈H₄₁N₃O:C,82.12；H,7.44；N,7.56.Found:C,82.10；H,7.54；N,7.48％.

Example 7

Synthesis of ligand L7

(1) Synthesis of N- [2- (pyrazol-1-yl) ethyl ] benzylamine

The procedure is as in example 1, except that benzylamine (14.0g, 131mmol), potassium carbonate (3.98g, 28.8mmol) and 1- (2-bromoethyl) pyrazole (4.56g, 26.2mmol) are used as starting materials. A pale yellow viscous liquid was obtained (4.68g, crude yield 88.9%, purity about 80%).

(2) Synthesis of ligand L7

The procedure was as in example 1 except for using N- [2- (pyrazol-1-yl) ethyl ] benzylamine (4.68g, purity about 80%, about 18.6mmol), anhydrous potassium carbonate (3.09g, 22.4mmol) and 2-bromomethyl-4-methyl-6-tritylphenol (8.26g, 18.6mmol) as starting materials. Column chromatography separation and purification gave a white solid (6.30g, 60.1%).

¹H NMR(CDCl₃,400MHz,298K)δ10.19(s,1H,OH),7.43(d,³J＝2.0Hz,1H, Pyrazolyl-H),7.25–7.19(m,14H,ArH),7.18–7.11(m,3H,ArH),7.03(d,³J＝2.0Hz,1H, Pyrazolyl-H),6.93(s,1H,ArH),6.90–6.82(m,2H,ArH),6.76(s,1H,ArH),6.11(t,³J＝2.0Hz, 1H,Pyrazolyl-H),3.75(t,³J＝6.3Hz,2H,Pyrazolyl-CH₂CH₂),3.59(s,2H,ArCH₂N),3.27(s,2H, PhCH₂),2.78(t,³J＝6.3Hz,2H,Pyrazolyl-CH₂CH₂),2.17(s,3H,ArCH₃).¹³C{¹H}NMR(CDCl₃, 100MHz,298K):δ.153.6,146.0,139.7,136.1,134.0,131.2,130.9,130.3,130.2,129.8,128.8, 128.5,127.5,127.1,127.0,125.5,121.9,105.3(all Ar-C and Pyrazolyl-C),63.2(CPh₃),58.9 (ArCH₂N),58.4(PhCH₂),52.0(Pyrazolyl-CH₂CH₂N),50.2(Pyrazolyl-CH₂CH₂N),21.0(ArCH₃). Anal.Calcd.for C₃₉H₃₇N₃O:C,83.09；H,6.62；N,7.45.Found:C,82.94；H,6.63；N,7.30％.

Example 8

Synthesis of Zinc Complex Zn1

Under the protection of argon, Zn [ N (SiMe) is added₃)₂]₂(270mg, 0.700mmol) was added to a 50mL Schlenk flask, dissolved in 8mL of anhydrous tetrahydrofuran, followed by dropwise addition of ligand L1(409mg, 0.700mmol) in 8mL of anhydrous tetrahydrofuran, allowed to react overnight at room temperature, and the solvent and all volatiles were removed under reduced pressure. Recrystallization from tetrahydrofuran/n-hexane gave a white solid (223mg, 39.4%).

¹H NMR(C₆D₆,400MHz,298K):δ7.49(d,³J＝7.3Hz,6H,ArH),7.37(d,⁴J＝2.0Hz 1H, ArH),6.98(t,³J＝7.2Hz,6H,ArH),6.85(t,³J＝6.9Hz,3H,ArH),6.73(d,⁴J＝2.0Hz,1H,ArH), 5.25(s,1H,Pyrazolyl-H),4.34(d,²J＝12.1Hz,1H,ArCH₂N),3.57(m,6H,1.5×4H of THF), 3.20-3.08(m,2H,ArCH₂N and Pyrazolyl-CH₂),2.82-2.73(m,1H,Pyrazolyl-CH₂CH₂),2.60-2.50 (m,3H,Pyrazolyl-CH₂ and Pyrazolyl-CH₂CH₂ and NCH₂ of n-hexyl),2.28(s,3H,ArCH₃),2.03(s, 3H,Pyrazolyl-CH₃),2.00-1.93(m,1H,NCH₂ of n-hexyl),1.65-1.55(m,1H,CH₂ of n-hexyl), 1.45–1.37(m,6H,1.5×4H of THF),1.29(s,3H,Pyrazolyl-CH₃),1.27–1.14(m,5H,CH₂ of n-hexyl),1.13-1.01(m,2H,CH₂ of n-hexyl),0.91(t,³J＝6.8Hz,3H,CH₃ of n-hexyl),0.32(br s, 9H,SiMe₃),0.13(br s,9H,SiMe₃).¹³C{¹H}NMR(C₆D₆,100MHz,298K):δ164.5,150.4,140.1, 137.0,131.8,131.2,128.4,128.3,127.8,126.9,125.1,121.9,119.9(all Ar-C and Pyrazolyl-C), 67.8(THF),64.1(CPh₃),60.8(ArCH₂N),58.4(NCH₂),54.9(Pyrazolyl-CH₂CH₂N),44.7 (Pyrazolyl-CH₂CH₂N),32.1(CH₂ of n-hexyl),27.6(CH₂ of n-hexyl),25.8(CH₂ of n-hexyl),25.8 (THF),23.1(hexane),21.1(CH₂ of n-hexy),21.0(ArCH₃),20.9(CH₃ of n-hexyl),14.4 (Pyrazolyl-CH₃),10.4(Pyrazolyl-CH₃),6.6(SiMe₃),6.3(SiMe₃).Anal.Calcd.for C₄₆H₆₄N₄OSi₂Zn·1.5C₄H₈O:C,67.98；H,8.34；N,6.10.Found:C,68.00；H,8.54；N,6.36％.

Example 9

Synthesis of Zinc Complex Zn2

Under the protection of argon, Zn [ N (SiMe) is added₃)₂]₂(386mg, 1.00mmol) is added into a 50mLSchlen bottle, dissolved by 8mL of anhydrous toluene, then 8mL of anhydrous toluene solution of ligand L2(583mg, 1.00mmol) is added dropwise, reaction is carried out at room temperature overnight, a large amount of white solid is separated out from the reaction system, filtration is carried out, filter residue is washed by n-hexane, and the white solid is obtained by pumping out (664mg, 82.3%).

¹H NMR(C₆D₆,400MHz,298K):δ7.47(br s,6H,ArH),7.32(d,⁴J＝2.0Hz,1H,ArH), 7.13-7.11(m,1H,0.5×2H of toluene),7.07–6.92(m,7.5H,0.5×3H of toluene and 6H of ArH), 6.88(br t,³J＝6.0Hz,3H,ArH),6.76(d,⁴J＝2.0Hz,1H,ArH),5.28(s,1H,Pyrazolyl-H),4.42(d, ²J＝12.0Hz,1H,ArCH₂N),3.20(br s,1H,Pyrazolyl-CH₂),2.98(d,²J＝12.0Hz,1H,ArCH₂N), 2.97-2.68(m,4H,Pyrazolyl-CH₂ and Pyrazolyl-CH₂CH₂ and NCH of cyclohexyl),2.29(s,3H, ArCH₃),2.10(s,1.5H,0.5×3H of toluene),2.08-2.00(m,1H,CH₂ of cyclohexyl),1.97(br s,3H, Pyrazolyl-CH₃),1.74(br s,1H,CH₂ of cyclohexyl),1.60(br s,1H,CH₂ of cyclohexyl),1.45(br s, 1H,CH₂ of cyclohexyl),1.35(s,3H,Pyrazolyl-CH₃),1.29-1.13(m,3H,CH₂ of cyclohexyl), 1.12-0.97(m,1H,CH₂of cyclohexyl),0.97-0.81(m,2H,CH₂ of cyclohexyl),0.19(br s,18H, N(SiMe₃)₂).¹³C{¹H}NMR(C₆D₆,100MHz,298K):164.0,150.5,140.1,137.9(toluene),136.4, 134.0,131.8,129.3(toluene),128.6(toluene),128.4,128.3,127.8,127.1,125.7(toluene),125.2, 119.9(all Ar-C and Pyrazolyl-C),64.1(CPh₃),54.6(Pyrazolyl-CH₂CH₂N),30.2(NCH),27.5(CH₂ of cyclohexyl),26.3(CH₂ of cyclohexyl),26.0(CH₂ of cyclohexyl),21.4(ArCH₃),21.1(toluene), 14.5(Pyrazolyl-CH₃),10.5(Pyrazolyl-CH₃),6.2(Pyrazolyl-CH₃).Due to the poor solubility in C₆D₆,only partial ¹³C signals could be observed.Anal.Calcd.for C₄₆H₆₂N₄OSi₂Zn·0.5C₇H₈:C, 69.57；H,7.78；N,6.56.Found:C,69.56；H,8.03；N,6.56％.

Example 10

Synthesis of Zinc Complex Zn3

Under the protection of argon, Zn [ N (SiMe) is added₃)₂]₂(386mg, 1.00mmol) was added to a 50mL Schlenk flask and dissolved in 8mL of dry toluene, then ligand L3(592mg, 1.00mmol) was added dropwise in 8mL of dry toluene, the reaction was allowed to proceed overnight at room temperature, and the solvent and all volatiles were removed under reduced pressure. Recrystallization from toluene/n-hexane precipitated crystals, which were then dried to give a white solid (380mg, 46.6%).

¹H NMR(C₆D₆,400MHz,298K):δ7.48(d,³J＝6.4Hz,6H,ArH),7.29(d,⁴J＝1.8Hz,1H, ArH),7.12–7.07(m,3H,ArH),6.99(t,³J＝6.4Hz,6H,ArH),6.93–6.81(m,5H,ArH),6.39(d,⁴J ＝1.8Hz,1H,ArH),5.27(s,1H,Pyrazolyl-H),4.44(d,²J＝14.2Hz,1H,PhCH₂),4.39(d,²J＝12.0 Hz,1H,ArCH₂N),3.98(d,²J＝14.2Hz,1H,PhCH₂),3.12(d,²J＝12.0Hz,1H,ArCH₂N),2.93(dd, ²J＝15.6Hz,³J＝10.3Hz,1H,Pyrazolyl-CH₂CH₂),2.65(br d,²J＝15.6Hz,1H, Pyrazolyl-CH₂CH₂),2.55-2.40(m,2H,Pyrazolyl-CH₂CH₂ and Pyrazolyl-CH₂CH₂),2.10(s,3H, ArCH₃),2.08(s,3H,Pyrazolyl-CH₃),1.29(s,3H,Pyrazolyl-CH₃),1.27–1.16(m,4H,0.5×8H of n-hexane),0.88(t,³J＝6.8Hz,3H,0.5×6H of n-hexane),0.38(br s,9H,SiMe₃),0.12(br s,9H, SiMe₃).¹³C{¹H}NMR(C₆D₆,100MHz,298K):δ164.6,150.4,140.3,137.1,133.8,132.0,131.8, 131.1,129.3,128.8,128.7,128.6,126.9,125.2,122.2,120.1,106.3(all Ar-C and Pyrazolyl-C), 64.5(PhCH₂N),64.1(CPh₃),61.1(ArCH₂N),55.7(PyCH₂CH₂N),45.3(Pyrazolyl-CH₂CH₂N), 32.0(hexane),23.1(hexane),20.9(ArCH₃),14.7(Pyrazolyl-CH₃),10.5(Pyrazolyl-CH₃),6.7 (SiMe₃),6.1(SiMe₃).Anal.Calcd.for C₄₇H₅₈N₄OSi₂Zn·0.5C₆H₁₄:C,69.86；H,7.62；N,6.52. Found:C,69.93；H,7.68；N,6.29％.

Example 11

Synthesis of Zinc Complex Zn4

Except that the raw material adopts Zn [ N (SiMe)₃)₂]₂(430mg, 1.11mmol) and L4(674mg, 1.11mmol), the same procedure was followed as in example 9. White solid was obtained (669mg, 80.8%).

¹H NMR(C₆D₆,400MHz,298K):δ7.50(d,³J＝6.9Hz,6H,ArH),7.40(d,⁴J＝2.1Hz,1H, ArH),7.15-7.12(m,2H,PhH),7.05(t,³J＝7.3Hz,1H,PhH),7.02-6.90(m,8H,ArH and PhH), 6.84(t,³J＝6.9Hz,3H,ArH),6.78(d,⁴J＝2.1Hz,1H,ArH),5.23(s,1H,Pyrazolyl-H),4.42(d,²J ＝12.0Hz,1H,ArCH₂N),3.56(m,1H,0.25×4H of THF),3.50-3.40(m,1H,Pyrazolyl-CH₂),3.26 (d,²J＝12.0Hz,1H,ArCH₂N),2.90–2.71(m,3H,Pyrazolyl-CH₂CH₂,Pyrazolyl-CH₂CH₂ and PhCH₂CH₂),2.63-2.53(m,2H,Pyrazolyl-CH₂CH₂ and PhCH₂CH₂),2.40-2.27(m,1H, PhCH₂CH₂),2.31(s,3H,ArCH₃),2.16-2.06(m,1H,PhCH₂CH₂),2.00(s,3H,Pyrazolyl-CH₃), 1.40(m,0.25×4H of THF),1.29(s,3H,Pyrazolyl-CH₃),1.18-1.26(m,2.4H,0.3×8H of hexane), 0.93–0.81(t,³J＝6.7Hz,1.8H,0.3×6H of hexane),0.29(br s,9H,SiMe₃),-0.06(br s,9H,SiMe₃). ¹³C{¹H}NMR(C₆D₆,100MHz,298K):δ164.5,150.4,140.2,138.9,137.9,137.2,133.9,131.8, 131.2,128.4,128.3,127.8,126.9,125.8,125.1,121.8,120.0,106.3(all Ar-C and Pyrazolyl-C), 64.1(CPh₃),62.4(PhCH₂CH₂N),60.9(ArCH₂N),55.3(Pyrazolyl-CH₂CH₂N),44.9 (Pyrazolyl-CH₂CH₂N),27.7(PhCH₂CH₂N),21.1(ArCH₃),14.4(Pyrazolyl-CH₃),10.4 (Pyrazolyl-CH₃),6.4(N(SiMe₃)₂),6.2(N(SiMe₃)₂).Anal.Calcd.for C₄₈H₆₀N₄OSi₂Zn·0.3C₆H₁₄·0.25C₄H₈O:C,69.78；H,7.63；N,6.41.Found:C,69.47；H,7.61；N, 6.38％.

Example 12

Synthesis of Zinc Complex Zn5

Except that the raw material adopts Zn [ N (SiMe)₃)₂]₂(386mg, 1.00mmol) and L5(557mg, 1.00mmol), the same procedure was followed as in example 8. White solid (228mg, 29.2%) was obtained.

¹H NMR(C₆D₆,400MHz,298K):δ7.52(d,³J＝7.5Hz,6H,ArH),7.38(s,1H,ArH),7.01(t, ³J＝7.2Hz,6H,ArH),6.86(t,³J＝7.0Hz,3H,ArH),6.81(s,1H,ArH),6.67(s,1H,Pyrazolyl-H), 5.98(s,1H,Pyrazolyl-H),5.51(s,1H,Pyrazolyl-H),4.36(d,²J＝12.0Hz,1H,ArCH₂),3.57(m, 0.5H,0.125×4H of THF),2.90-2.68(m,3H,ArCH₂ and Pyrazolyl-CH₂ and Pyrazolyl-CH₂CH₂), 2.53–2.31(m,2H,ArCH₂ and Pyrazolyl-CH₂CH₂),2.26(s,3H,ArCH₃),2.19(t,²J＝12.1Hz,1H, NCH₂ of n-hexyl),1.93(br s,1H,CH₂ of n-hexyl),1.71(t,³J＝11.4Hz,1H,NCH₂ of n-hexyl), 1.45-1.37(m,0.5H,0.125×4H of THF),1.37-1.13(m,6H,CH₂ of n-hexyl),1.07(br s,1H,CH₂ of n-hexyl),0.93(br s,3H,CH₃ of n-hexyl),0.19(s,18H,N(SiMe₃)₂).¹³C{¹H}NMR(C₆D₆,100 MHz,298K):δ164.5,150.4,140.1,137.0,133.7,131.8,131.5,128.4,128.3,127.8,126.9,125.2, 119.9(all Ar-C and Pyrazolyl-C),67.8(THF),64.1(CPh₃),61.6(ArCH₂N),61.2(NCH₂),56.2 (Pyrazolyl-CH₂CH₂N),48.4(Pyrazolyl-CH₂CH₂N),32.0(CH₂ of n-hexyl),27.7(CH₂of n-hexyl), 25.8(THF),23.1(CH₂ of n-hexyl),21.2(CH₂ of n-hexyl),21.1(ArCH₃),14.3(CH₃ of n-hexyl),), 6.4(N(SiMe₃)₂).Anal.Calcd.for C₄₄H₆₀N₄OSi₂Zn·0.125C₄H₈O:C,67.52；H,7.77；N,7.08.Found: C,67.05；H,7.68；N,6.99％.

Example 13

Synthesis of Zinc Complex Zn6

Except that the raw material adopts Zn [ N (SiMe)₃)₂]₂(386mg, 1.00mmol) and L6(555mg, 1.00mmol), the same procedure as in example 9 was followed. A white solid was obtained (713mg, 91.6%).

¹H NMR(C₆D₆,400MHz,298K):δ7.53(d,³J＝7.7Hz,6H,ArH),7.38(d,⁴J＝2.1Hz,1H, ArH),7.15-7.12(m,1.8H,0.9×2H of toluene),7.07–6.90(m,8.7H,0.9×3H of toluene and 6H of ArH),6.93(br s,1H,ArH),6.84(t,³J＝7.3Hz,3H,ArH),6.68(d,³J＝2.3Hz,1H,Pyrazolyl-H), 6.00(d,³J＝2.3Hz,1H,Pyrazolyl-H),5.53(t,³J＝2.3Hz,1H,Pyrazolyl-H),4.27(d,²J＝11.8Hz, 1H,ArCH₂N),3.57(m,0.52H,0.13×4H of THF),3.17(br d,1H,³J＝5.8Hz，NCH),2.87(d,²J＝ 11.8Hz,1H,ArCH₂N),2.73-2.61(m,1H,Pyrazolyl-CH₂),2.51(t,³J＝10.4Hz,1H, Pyrazolyl-CH₂CH₂),2.44-2.34(m,2H,Pyrazolyl-CH₂CH₂ and NCH),2.27(s,3H,ArCH₃),2.10(s, 2.7H,0.9×3H of toluene),1.83-1.67(m,2H,CH₂ of cyclohexyl),1.63-1.55(m,1H,CH₂ of cyclohexyl),1.50-1.43(m,1H,CH₂ of cyclohexyl),1.42-1.38(m,0.52H,0.13×4H of THF), 1.35-1.25(m,1H,CH₂ of cyclohexyl),1.22-1.08(m,2H,CH₂ of cyclohexyl),1.02–0.86(m,3H, CH₂ of cyclohexyl),0.21(s,18H,N(SiMe₃)₂).¹³C{¹H}NMR(C₆D₆,100MHz,298K):δ164.9, 147.7,136.7,133.6,132.0,131.5,131.0,127.8,127.0,125.3,121.9,120.3,105.4(all Ar-C and Pyrazolyl-C),64.1(CPh₃),62.9(ArCH₂N),61.0(NCH),53.8(Pyrazolyl-CH₂CH₂N),48.3 (Pyrazolyl-CH₂CH₂N),20.9(ArCH₃),6.5(N(SiMe₃)₂).The too much weak product signal strength is beacaus of the poor solubility of the complex.Anal.Calcd.for C₄₄H₅₈N₄OSi₂Zn·0.9C₇H₈·0.13C₄H₈O:C,69.93；H,7.65；N,6.42.Found:C,69.62；H,7.55；N, 6.31％.

Example 14

Synthesis of Zinc Complex Zn7

Except that the raw material adopts Zn [ N (SiMe)₃)₂]₂(611mg, 1.58mmol) and L7(892mg, 1.58mmol), the procedure was as in example 9. White solid (741mg, 60.4%) was obtained.

¹H NMR(C₆D₆,400MHz,298K):δ7.54(d,³J＝7.5Hz,6H,ArH),7.32(d,⁴J＝2.1Hz,1H, ArH),7.13–7.08(m,5.5H,1.5×2H of toluene and 3H of ArH),7.08–6.97(m,10.5H,1.5×3H of toluene and 6H of ArH),6.91(t,³J＝7.2Hz,3H,ArH),6.86(d,³J＝6.4Hz,2H,ArH),6.69(br s, 1H,ArH),6.29(d,³J＝2.3Hz,1H,Pyrazolyl-H),6.03(d,³J＝2.3Hz,1H,Pyrazolyl-H),5.53(t,³J ＝2.3Hz,1H,Pyrazolyl-H),4.34(pesudo d,²J＝14.1Hz,2H,PhCH₂N and ArCH₂N),3.93(d,²J＝ 14.4Hz,1H,PhCH₂N),2.98(d,²J＝12.1Hz,1H,ArCH₂N),2.85-2.70(m,1H, Pyrazolyl-CH₂CH₂),2.75-2.60(m,1H,Pyrazolyl-CH₂CH₂),2.41-2.27(m,2H,Pyrazolyl-CH₂CH₂ and Pyrazolyl-CH₂CH₂),2.10(s,4.5H,1.5×3H of toluene),2.07(s,3H,ArCH₃),0.23(s,18H, N(SiMe₃)₂).¹³C{¹H}NMR(C₆D₆,100MHz,298K):164.9,147.7,142.3,133.6,136.7,132.2, 132.0,131.6,131.0,128.6,127.1,127.0,125.2,121.9,120.3,105.4,105.3(all Ar-C and Pyrazolyl-C),64.1(CPh₃),62.9(ArCH₂N),61.0(PhCH₂N),53.7(Pyrazolyl-CH₂CH₂N),48.2 (Pyrazolyl-CH₂CH₂N),21.02(toluene),20.96(ArCH₃),6.5(N(SiMe₃)₂).Anal.Calcd.for C₄₅H₅₄N₄OSi₂Zn·1.5C₇H₈:C,71.93；H,7.18；N,6.05.Found:C,71.45；H,6.90；N,6.51％.

Example 15

Under the protection of argon, polymerizingRacemic lactide (0.144g,1.00mmol) was added to the flask and dissolved in 0.5mL of toluene. 0.5mL of a toluene solution of catalyst Zn3 was measured and added to the polymerization flask. [ rac-LA]₀＝1.0M，[Zn]₀＝0.005M，[Zn]₀: [rac-LA]₀1: 200. Controlling the reaction temperature to be 25 +/-1 ℃, reacting for 35 hours, and adding petroleum ether to terminate the reaction. The solvent was removed by suction, the residue was dissolved in methylene chloride, and methanol was added to precipitate the polymer. Vacuum drying for 24 h. Conversion rate: 82%, M_n＝ 7.9×10⁴g/mol, molecular weight distribution PDI of 1.73, isotacticity P_m＝0.70。

Example 16

The same procedure as in example 15 was repeated except that the catalyst was changed to Zn3 and the solvent was changed to tetrahydrofuran, and the reaction was carried out for 38 hours, the conversion: 82%, M_n＝6.4×10⁴g/mol, molecular weight distribution PDI of 1.49, isotacticity P_m＝0.69。

Example 17

The same procedure as in example 15 was repeated except that the catalyst was changed to Zn5, and the reaction time was 4.5 hours, conversion: 89%, M_n＝19.4×10⁴g/mol, molecular weight distribution PDI of 1.91, isotacticity P_m＝0.87。

Example 18

The same procedure as in example 15 was repeated except that the catalyst was changed to Zn5 and the solvent was changed to tetrahydrofuran, and the reaction time was 56 minutes, the conversion: 85%, M_n＝6.0×10⁴g/mol, molecular weight distribution PDI of 1.80, isotacticity P_m＝0.86。

Example 19

The same procedure as in example 15 was repeated except that the catalyst was changed to Zn6, and the reaction time was 4.5 hours, conversion: 86%, M_n＝19.9×10⁴g/mol, molecular weight distribution PDI of 1.95, isotacticity P_m＝0.91。

Example 20

The procedure of example 15 was repeated except that the catalyst was changed to Zn6 and the solvent was changed to tetrahydrofuran, and the reaction was carried out for 75 minutes to obtain a conversion: 83%, M_n＝6.7×10⁴g/mol, molecular weight distribution PDI of 1.98, isotacticity P_m＝0.89。

Example 21

The same procedure as in example 15 was carried out, except that the catalyst was changed to Zn7, the reaction time was 2 hours, and the conversion: 87%, M_n＝8.8×10⁴g/mol, molecular weight distribution PDI 2.00, isotacticity P_m＝0.73。

Example 22

The same procedure as in example 15 was repeated except that the catalyst was changed to Zn7 and the solvent was changed to tetrahydrofuran, and the reaction time was 50 minutes, the conversion: 93%, M_n＝6.0×10⁴g/mol, molecular weight distribution PDI of 1.71, isotacticity P_m＝0.71。

Example 23

Racemic lactide (0.144g,1.00mmol) was added to a polymerization flask under argon and dissolved with 0.5mL of isopropanol in toluene. 0.5mL of a toluene solution of catalyst Zn5 was measured and added to the polymerization flask. [ rac-LA]₀＝1.0M，[Zn]₀＝0.005M，[Zn]₀:[ⁱPrOH]₀:[rac-LA]₀1:1: 200. Controlling the reaction temperature to be 25 +/-1 ℃, reacting for 22 minutes, and adding petroleum ether to terminate the reaction. The solvent was removed by suction, the residue was dissolved in methylene chloride, and methanol was added to precipitate the polymer. Vacuum drying for 24 h. Conversion rate: 93%, M_n＝3.1×10⁴g/mol, molecular weight distribution PDI of 1.52, isotacticity P_m＝0.87。

Example 24

The reaction was carried out in the same manner as in example 23 except that the catalyst was changed to Zn5 and the reaction solvent was changed to tetrahydrofuran, for 14 minutes, and the conversion: 91%, M_n＝3.3×10⁴g/mol, molecular weight distribution PDI of 1.42, isotacticity P_m＝0.84。

Example 25

The same procedure as in example 23 was repeated except that the catalyst was changed to Zn6, and the reaction time was 29 minutes, conversion: 96%, M_n＝4.0×10⁴g/mol, molecular weight distribution PDI of 1.56, isotacticity P_m＝0.89。

Example 26

The procedure of example 23 was repeated except that the catalyst was changed to Zn6 and the reaction solvent was changed to tetrahydrofuran, and the reaction was carried out for 20 minutesClock, conversion: 92%, M_n＝4.8×10⁴g/mol, molecular weight distribution PDI of 1.33, isotacticity P_m＝0.86。

Example 27

The same procedure as in example 23 was repeated except that the catalyst was changed to Zn7, and the reaction time was 22 minutes, conversion: 92%, M_n＝3.6×10⁴g/mol, molecular weight distribution PDI of 1.61, isotacticity P_m＝0.72。

Example 28

The reaction was carried out in the same manner as in example 23 except that the catalyst was changed to Zn7 and the reaction solvent was changed to tetrahydrofuran, for 12 minutes, and the conversion: 86%, M_n＝2.4×10⁴g/mol, molecular weight distribution PDI of 1.41, isotacticity P_m＝0.72。

Example 29

The same procedure as in example 23 was repeated except that the catalyst was changed to Zn6 and the polymerization temperature was-40 deg.C, the reaction time was 21 hours, the conversion: 85%, M_n＝3.0×10⁴g/mol, molecular weight distribution PDI of 1.36, isotacticity P_m＝0.93。

Example 30

To a 10mL polymerization flask was added racemic lactide (144mg, 1.00mmol), 0.1mL of isopropanol/toluene solution was added, and 0.1mL of a toluene solution of catalyst Zn5 was added. Maintenance of [ rac-LA]₀/[Zn]₀/[ⁱPrOH]₀1000:1: 1. Stirring in 110 + -1 deg.C oil bath, reacting for 3min, and adding petroleum ether to terminate polymerization. The solvent was removed by suction, the residue was dissolved in methylene chloride, and methanol was added to precipitate the polymer. Vacuum drying for 24 h. Conversion rate: 89%, M_n＝25.0×10⁴g/mol, molecular weight distribution PDI of 1.72, isotacticity P_m＝0.79。

Example 31

Except for [ rac-LA]₀/[Zn]₀/[ⁱPrOH]₀The procedure is as in example 30 except 1500:1:1, after 8min, conversion: 97%, M_n＝24.2×10⁴g/mol, molecular weight distribution PDI of 1.61, isotacticity P_m＝0.72。

Example 32

Except for [ rac-LA]₀/[Zn]₀/[ⁱPrOH]₀The procedure of example 30 was otherwise the same as that of example 5000:1:1, and after 13min, the conversion: 92%, M_n＝48.3×10⁴g/mol, molecular weight distribution PDI 1.43.

Example 33

The same procedure as in example 15 was repeated except that the catalyst was changed to Zn5, the solvent was changed to tetrahydrofuran, and the monomer was changed to D-LA, and the reaction time was 22min, after which the conversion: 90%, M_n＝6.4×10⁴g/mol, molecular weight distribution PDI 1.49.

Example 34

The same procedure as in example 15 was repeated except that the catalyst was changed to Zn5, the solvent was changed to tetrahydrofuran, and the monomer for polymerization was changed to L-LA, and the reaction time was 26min, after which the conversion: 93%, M_n＝6.6×10⁴g/mol, molecular weight distribution PDI 1.53.

Example 35

The procedure of example 23 was followed, except that the polymerized monomers were changed to epsilon-caprolactone, and after 11min, the conversion: 94%, M_n＝2.4×10⁴g/mol, molecular weight distribution PDI 1.38.