Trivalent rare earth metal alkylate containing chiral bridged diimino, preparation method and application

Abstract

The invention aims to provide a chiral bridged diimine group-containing trivalent rare earth metal alkylate as well as a preparation method and application thereof, and the chiral bridged diimine group-containing trivalent rare earth metal alkylate is characterized in that each central metal in the chiral bridged diimine group-containing trivalent rare earth metal alkylate is connected with four nitrogen atoms of a ligand to form a chelating structure taking rare earth metal as a center; in addition, the compound is sensitive to air and water, and has solubility in polar and non-polar organic solvents. The chiral bridged diimino-containing trivalent rare earth metal alkylate provided by the invention has strong stability on one hand, and can also be used as a catalyst for intramolecular hydroamination reaction on the other hand.

Description

Technical Field

[0001] The present application belongs to the field of synthesis and application of trivalent rare earth metal alkyls containing chiral bridged diimino groups, and in particular to a trivalent rare earth metal alkyl containing chiral bridged diimino groups, a preparation method and an application thereof. Background Art

[0002] Rare earth metal alkyl complexes contain rare earth metal-C (σ) bonds, usually have high reactivity, and play an important role in rare earth metal organic complexes. Generally, they are more unstable than rare earth metal halides and amine complexes. Therefore, the synthesis of rare earth metal hydrocarbyl complexes, especially hydrocarbyl complexes with larger ionic radius, is also difficult. It was not until 2006 that the Okuda research group discovered the method of using alkane elimination reaction to synthesize rare earth alkyl complexes, which promoted the development of monocyclopentadienyl rare earth hydrocarbyl complexes. They used alkane elimination method to synthesize monocyclopentadienyl rare earth dialkyl complexes with no side chain functional groups. With the rapid development of non-cyclopentadienyl rare earth metal organic chemistry, highly active non-cyclopentadienyl rare earth hydrocarbyl complexes have also aroused widespread interest. In 1992, Schaverien's research group used large sterically hindered biphenol as ligand to synthesize a series of rare earth metal alkyl complexes, and found that such ligands can stabilize rare earth metal hydrocarbyl complexes containing rare earth metal-carbon bonds. The Schrock research group synthesized NON-type dianionic ligands and obtained a series of rare earth metal hydrocarbon-based complexes containing such ligands. The Mountford research group designed and synthesized a class of tetradentate dianionic ligands containing pyridine side chains, which can also stabilize rare earth metal chlorides and alkyl compounds.

[0003] β-Diimine ligands are an important class of nitrogen-donating ligands in non-locene rare earth metal organic chemistry. This class of ligands has a good stabilizing effect on rare earth metal halides, amines and divalent rare earth metal complexes. A large number of rare earth complexes containing β-diimine ligands have been synthesized, but the stability to more active hydrocarbons containing rare earth metal-C bonds is not very good. This class of hydrocarbon-based complexes is prone to ligand redistribution, dimerization or elimination reactions, etc. Therefore, the synthesis of hydrocarbons containing this class of ligands is relatively difficult, and there are few reported examples.

[0004] At present, a dimethyl complex of rare earth metal scandium is synthesized by using a β-diimine ligand substituted with a large steric hindrance 2, 6-diisopropylphenyl; but other rare earth metal alkyl complexes with a larger ionic radius are very unstable and have not been separated; an alkyl complex of cerium is also obtained by using a large steric hindrance β-diimine ligand through a salt elimination reaction; and a tetradentate nitrogen β-diimine ligand is designed and synthesized by introducing two symmetrical side chains on a nitrogen-containing donor, and a series of rare earth metal halides, amine complexes and divalent rare earth metal complexes are synthesized using the ligand, but when synthesizing hydrocarbon complexes, only one hydrocarbon complex of terbium is obtained; and a β-diimine ligand modified with an N, N-dimethylethylenediamine side arm is designed and synthesized, and a series of β-diimine rare earth alkylates with a mononuclear structure are synthesized by using the alkyl elimination reaction of the ligand with a trialkyl rare earth hydrocarbon.

[0005] In view of the fact that the stability of mono-β-diimine ligands to alkyl compounds containing rare earth metal-C bonds is not very good, a stable trivalent rare earth metal alkyl compound containing a chiral bridging diimine group is in urgent need of development. Summary of the invention

[0006] The purpose of the present application is to provide a nitrogen-containing bridged alkyl aluminum complex, a preparation method and application thereof, so as to at least solve one technical problem in the prior art.

[0007] The technical solution of this application is: A trivalent rare earth metal alkyl compound containing a chiral bridged diimino group, comprising: Each central metal in the trivalent rare earth metal alkyl compound containing a chiral bridging diimino group is connected to four nitrogen atoms of the ligand to form a chelate structure centered on the rare earth metal; and It is sensitive to air and water and is soluble in both polar and non-polar organic solvents.

[0008] The trivalent rare earth metal alkyl compound containing a chiral bridging diimino group comprises: {Cy[NC(Me)CHC(Me)NAr]2}RECH2SiMe3[RE = Dy(1), Er(2), Yb(3), Y(4)]; their molecular formulas are: ;or, ;or, ;or, .

[0009] The polar and non-polar organic solvents include: One or more of n-hexane, toluene and tetrahydrofuran.

[0010] A method for preparing the trivalent rare earth metal alkyl compound containing a chiral bridged diimino group as described above comprises: (1R,2R)-(-)-1,2-cyclohexanediamine, 2,6-diisopropylaniline acetone imine and a catalytic amount of p-toluenesulfonic acid are stirred and heated under reflux overnight in a toluene solution, and water and toluene produced during the reaction are azeotropically separated; After the reaction was completed, the toluene was removed by rotary evaporation, and the remaining thick material was mixed with n-hexane for crystallization to obtain: Cy[NHC(Me)CHC(Me)NAr]2 (Cy=(1R,2R)-(-)-1,2-cyclohexyl, Ar=2,6- i Pr2C6H3)(H2L 3 ); At room temperature, 3 A diimino trivalent rare earth metal alkylate is added to the n-hexane solution, the reaction is stirred, and the solvent is removed under reduced pressure. The residue is dissolved in n-hexane, and the extract is filtered into a single-necked bottle and placed in an environment of 0°C to obtain a complex containing a chiral bridged diimino trivalent rare earth metal alkylate.

[0011] The diimino trivalent rare earth metal alkyl compound comprises: Dy III [CH2SiMe3]3(THF)2, Er III [CH2SiMe3]3(THF)2、Yb III [CH2SiMe3]3(THF)2 and Y III [CH2SiMe3]3(THF)2.

[0012] The method for preparing the trivalent rare earth metal alkyl compound containing a chiral bridged diimino group further comprises: (1R,2R)-(-)-1,2-cyclohexanediamine, 2,6-dimethylaniline acetylacetonimide and a catalytic amount of p-toluenesulfonic acid are stirred and heated under reflux overnight in a toluene solution, and the water and toluene produced in the reaction process are azeotropically separated; After the reaction was completed, the toluene was removed by rotary evaporation, and the remaining thick substance was mixed with hexane and crystallized to obtain: Cy[NHC(Me)CHC(Me)NAr]2 (Cy=(1R,2R)-(-)-1,2-cyclohexyl, Ar=2,6-Me2C6H3)(H2L 1 ).

[0013] The method for preparing the trivalent rare earth metal alkyl compound containing a chiral bridged diimino group further comprises: (1R,2R)-(-)-1,2-cyclohexanediamine, 2,6-diethylaniline acetylacetonimide and a catalytic amount of p-toluenesulfonic acid are stirred and heated under reflux overnight in a toluene solution, and water and toluene generated in the reaction process are azeotropically separated; After the reaction is completed, the toluene is removed by rotary evaporation, and the remaining thick substance is mixed with n-hexane and crystallized to obtain: Cy[NHC(Me)CHC(Me)NAr]2 (Cy=(1R,2R)-(-)-1,2-cyclohexyl, Ar=2,6-Et2C6H3)(H2L 2 ).

[0014] An application of the trivalent rare earth metal alkyl compound containing a chiral bridged diimino group as described above comprises: As a catalyst for intramolecular and intermolecular hydroamination reactions of compounds containing unsaturated carbon bonds.

[0015] The intramolecular hydroamination / cyclization reactions of the unsaturated carbon bond-containing compounds are all carried out in a Young NMR tube; Add 1 equivalent of an unsaturated carbon bond-containing compound, 0.1 equivalent of ferrocene as an internal standard, and 0.6 mL of C6D6 as a solvent to a Young NMR tube in sequence, take a set dose of the trivalent rare earth metal alkyl containing a chiral bridged diimino group as a catalyst, and then perform a NMR tracking reaction; At room temperature, the trivalent rare earth metal alkyl compound containing a chiral bridging diimino group catalyzes the substrate conversion of the compound containing an unsaturated carbon bond to undergo a hydroamination / cyclization reaction to generate a corresponding cyclic amine.

[0016] When the trivalent rare earth metal alkylate containing chiral bridging diimino group is used as a catalyst, its usage amount is greater than 3%.

[0017] The beneficial effects of this application include at least: The present application prepares chiral bridged β-diimine ligands with three substituents, and synthesizes four different rare earth metal complexes by alkyl elimination reaction with trialkyl rare earth hydrocarbons. On the one hand, the rare earth metal complex can ensure the stability of alkyl compounds containing rare earth metal-C bonds, and on the other hand, it can also serve as a catalyst for intramolecular hydrogenation reaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 For H2L 3 Compound 1 H NMR spectrum; Figure 2 For H2L 3 Compound 13 C NMR spectrum; Figure 3 is a crystal structure diagram of a complex; Figure 4 is the crystal structure diagram of another complex; Figure 5 is a crystal structure diagram of another complex; Figure 6 is a crystal structure diagram of another complex; Figure 7 for Figure 6 The complex shown 1 H NMR spectrum; Figure 8 for Figure 6 The complex shown 13 C NMR spectrum. DETAILED DESCRIPTION

[0019] The present application is further described below in conjunction with the accompanying drawings.

[0020] The purpose of the present application is to provide a trivalent rare earth metal alkyl compound containing a chiral bridging diimino group and a preparation process thereof. Specific embodiments

[0021] The present application provides a trivalent rare earth metal alkyl compound containing a chiral bridged diimino group, comprising the following steps: S1: Synthesis of chiral bridged diimine ligands: S101: Ligand Cy[NHC(Me)CHC(Me)NAr]2 (Cy=(1R,2R)-(-)-1,2-cyclohexyl, Ar=2,6-Me2C6H3)(H2L 1 ) Synthesis:

[0022] (1R,2R)-(-)-1,2-cyclohexanediamine (1.140 g, 10.0 mmol), 2,6-dimethylaniline acetylacetonimide (4.500 g, 22.0 mmol), and a catalytic amount of p-toluenesulfonic acid were stirred and heated under reflux overnight in a 30 mL toluene solution. A water separator was added to the reaction apparatus to azeotropically separate the water and toluene produced during the reaction. After the reaction was completed, the toluene was removed by rotary evaporation, and the remaining thick substance was mixed with hexane and crystallized at -20°C to obtain a yellow product H2L 1 (2.420 g, 50% yield). 1 H NMR (300 MHz, CDCl3, 25 °C, ppm): d= 10.86 (broad singlet, 2H, NH), 6.95 (multiplet, 4H, C6H3), 6.79 (multiplet, 2H, C6H3), 4.49 (singlet, 2H, β-CH), 3.06 (broad singlet, 2H, ring-CH), 2.09 (multiplet, 2H, ring-CH2), 1.96 (singlet, 6H, CH3), 1.62 (multiplet, 2H, ring-CH2), 1.88 (singlet, 6H, CH3), 1.51 (singlet, 6H, CH3), 1.49 (singlet, 6H, CH3), 1.25 - 1.16 (multiplet, 4H, ring-CH2). 13 13C NMR (75 MHz, CDCl3, 25 °C, ppm): d = 166.10, 155.27, 149.97, 128.24, 127.84, 127.70, 127.56, 121.79, 92.75, 58.12, 33.59, 24.78, 21.33, 19.73, 18.62, 18.35. IR (KBr pellet, cm -1 ): n = 3059 (weak), 2959 (medium), 2932 (weak), 2864 (medium), 1624 (strong), 1555 (strong), 1435 (medium), 1362 (medium), 1308 (strong), 1180 (strong), 1130 (medium), 1099 (medium), 1024 (medium), 935 (medium), 787 (strong), 760 (very strong), 733 (very strong), 698 (medium), 610 (medium).

[0023] S102: Ligand Synthesis of Cy[NHC(Me)CHC(Me)NAr]2 (Cy = (1R,2R)-(-)-1,2-cyclohexyl, Ar = 2,6-Et2C6H3) (H2L 2 ):

[0024] (1R,2R)-(-)-1,2-cyclohexanediamine (1.142 g, 10.0 mmol), 2,6-diethylaniline acetylacetonimide (5.090 g, 22.0 mmol), and a catalytic amount of p-toluenesulfonic acid were stirred and heated under reflux overnight in a 30 mL toluene solution. A water separator was added to the reaction apparatus to azeotropically separate the water and toluene produced during the reaction. After the reaction was completed, the toluene was removed by rotary evaporation, and the remaining thick substance was mixed with n-hexane and crystallized at -20°C to obtain a yellow product H2L 2 (2.590 g, 48% yield). 1 H NMR (300 MHz, CDCl3, 25 °C, ppm): d = 10.94 (br s, 2H, NH), 7.09(m, 4H, C6H3), 6.96 (m, 2H, C6H3), 4.58 (s, 2H, β-CH), 3.15 (br s, 2H, ring-CH), 2.43 (m, 8H, CH2CH3), 1.95 (s, 6H, CH3), 1.70 (m, 2H, ring-CH2), 1.66 (m,2H, ring-CH2), 1.60 (s, 6H, CH3), 1.24-1.10 (m, 4H, ring-CH2), 1.15 (m, 6H,CH3CH2), 1.12 (d, 6H, CH3CH2). 13 C NMR (75 MHz, CDCl3, 25 °C, ppm): d = 165.31,154.16, 147.65, 132.87, 132.68, 124.78, 124.55, 121.22, 91.90, 56.92, 32.52,24.02, 23.66, 23.32, 20.62, 18.58, 13.39. IR (KBr pellet, cm -1 ): n = 2928 (w),2859 (w), 1906 (w), 1842 (w), 1626 (s), 1553 (m), 1450 (s), 1371 (w), 1308(w), 1242 (s), 1184 (s), 1130 (m), 1024 (s), 959 (m), 870 (s), 797 (s), 731 (vs), 610 (s), 525 (m).

[0025] S103: Ligand Cy[NHC(Me)CHC(Me)NAr]2 (Cy=(1R,2R)-(-)-1,2-cyclohexyl, Ar=2,6- i Pr2C6H3) (H2L 3 ) Synthesis:

[0026] (1R,2R)-(-)-1,2-cyclohexanediamine (1.142 g, 10.0 mmol), 2,6-diisopropylaniline acetone imine (5.700 g, 22.0 mmol), and a catalytic amount of p-toluenesulfonic acid were stirred and heated under reflux overnight in a 30 mL toluene solution. A water separator was added to the reaction apparatus to azeotropically separate the water and toluene produced during the reaction. After the reaction was completed, the toluene was removed by rotary evaporation, and the remaining thick substance was mixed with n-hexane and crystallized at -20°C to obtain a yellow product H2L 3 (3.040 g, 51% yield). 1 H NMR (300 MHz, Chloroform- d ) δ 11.02 (s, 2H), 7.11 (d, J = 7.6 Hz,4H), 7.03 (d, J = 7.2 Hz, 2H), 4.61 (s, 2H), 3.18 (s, 2H), 2.90 (h, J = 7.4Hz, 4H), 1.98 (s, 6H), 1.91 (d, J = 14.7 Hz, 2H), 1.62 (s, 6H), 1.58 (s, 2H), 1.27 (s, 4H), 1.13 (d, J = 17.1 Hz, 24H). 13 C NMR (75 MHz, Chloroform- d ) δ 8.0, 21.9, 19.6.

[0027] like Figure 1, 2 we know that H2L 3 Compound 1 H NMR spectra and 13 C NMR spectrum.

[0028] S2: Synthesis of trivalent rare earth metal alkyls containing chiral bridging diimino groups.

[0029] S201: Complex {Cy[NC(Me)CHC(Me)NAr]2}DyCH2SiMe3(Cy=(1R,2R)-1,2-cyclohexyl, Ar=2,6- i Synthesis of Pr2C6H3) (1):

[0030] At room temperature, 3 Dy (0.480 g, 0.81 mmol) was added to a 20.0 mL hexane solution. III [CH2SiMe3]3(THF)2 (0.482 g, 0.85 mmol), after stirring for 6 hours, the color of the solution gradually changed from yellow to orange, the solvent was removed under reduced pressure, 10 mL of n-hexane was added to the residue and dissolved, the extract was filtered into a single-necked bottle and placed in an environment of 0°C, yellow crystals precipitated after a few days, and the complex {Cy[NC(Me)CHC(Me)NAr]2}DyCH2SiMe3 (1) (0.475 g, 70 % yield) was obtained. IR (KBr pellet, cm -1 ): n = 3059 (w), 2864 (w), 2509(w), 1624 (vs), 1554 (vs), 1435 (w), 1308 (s), 1223 (s), 1180 (vs), 1099 (s),1024 (s), 935 (m), 862 (vs), 787 (s), 733 (s) , 696 (s); Anal. Calc. forC 44 H 69 DyN4Si (844.6310): C, 62.57; H, 8.23; N, 6.63. Found: C, 62.11; H, 8.20; N, 6.60%.

[0031] like Figure 3 for: {Cy[NC(Me)CHC(Me)NAr]2}DyCH2SiMe3(Cy=(1R,2R)-1,2-cyclohexyl, Ar=2,6- i Figure 2. Crystal structure of Pr2C6H3).

[0032] S202: Synthesis of complex {Cy[NC(Me)CHC(Me)NAr]2}ErCH2SiMe3(2):

[0033] At room temperature, 3 Add Er (0.565 g, 0.95 mmol) to a 20.0 mL hexane solution III [CH2SiMe3]3(THF)2 (0.571 g, 1.00 mmol), after stirring for 6 hours, the color of the solution gradually changed from yellow to orange, the solvent was removed under reduced pressure, 10 mL of n-hexane was added to the residue and dissolved, the extract was filtered into a single-necked bottle and placed in an environment of 0°C, yellow crystals precipitated after a few days, and the complex {Cy[NC(Me)CHC(Me)NAr]2}ErCH2SiMe3 (2) (0.475 g, 70 % yield) was obtained. IR (KBr pellet, cm -1 ): n = 3059 (w), 2959 (s), 2864 (m), 1624 (vs), 1557 (vs), 1435 (m), 1308 (s), 1181 (vs), 1130 (w), 1099 (m),1024 (s), 934 (m), 862 (vs), 787 (s), 732 (m), 696 (m), 610 (w); Anal. Calc.for C 44 H 69 ErN4Si (849.3900): C, 62.22; H, 8.19; N, 6.60. Found: C, 61.91; H, 8.19; N, 6.57%.

[0034] like Figure 4 This is the crystal structure diagram of {Cy[NC(Me)CHC(Me)NAr]2}ErCH2SiMe3(2).

[0035] S203: Synthesis of the complex {Cy[NC(Me)CHC(Me)NAr]2}YbCH2SiMe3(3):

[0036] At room temperature, 3 Add Yb(II) (0.535 g, 0.90 mmol) to a 20.0 mL hexane solution III [CH2SiMe3]3(THF)2 (0.547 g, 0.94 mmol) was stirred for 6 hours. The color of the solution gradually changed from yellow to orange. The solvent was removed under reduced pressure. The residue was dissolved in 10 mL of n-hexane. The extract was filtered into a single-necked bottle and placed in an environment of 0°C. After a few days, yellow crystals precipitated to obtain the complex {Cy[NC(Me)CHC(Me)NAr]2}ErCH2SiMe3 (2) (0.475 g, 70% yield).

[0037] like Figure 5 This is the crystal structure diagram of {Cy[NC(Me)CHC(Me)NAr]2}ErCH2SiMe3 (2).

[0038] S204: Synthesis of complex {Cy[NC(Me)CHC(Me)NAr]2}YCH2SiMe3(4):

[0039] At room temperature, 3 Add Y (0.437 g, 0.73 mmol) to a 20.0 mL n-hexane solution III [CH2SiMe3]3(THF)2 (0.382 g, 0.77 mmol) was stirred for 6 hours. The color of the solution gradually changed from yellow to orange. The solvent was removed under reduced pressure. The residue was dissolved in 10 mL of n-hexane. The extract was filtered into a single-necked bottle and placed in an environment of 0°C. After a few days, yellow crystals precipitated to obtain the complex {Cy[NC(Me)CHC(Me)NAr]2}ErCH2SiMe3 (2) (0.475 g, 70% yield). 1 H NMR (300 MHz, Benzene- d 6) δ 7.28 – 7.17 (m, 6H), 4.81 (s, 1H), 4.78 (d, J = 1.6 Hz, 1H), 4.56 (t, J = 10.9 Hz, 1H), 3.61 (d, J= 7.9 Hz, 2H), 3.38 – 3.29 (m, 1H), 2.79 – 2.70 (m, 1H), 2.57 – 2.48 (m, 1H),2.37 (d, J = 12.4 Hz, 1H), 2.05 (d, J = 1.5 Hz, 3H), 2.14 – 1.43 (m, 7H),1.83 – 1.78 (m, 3H), 1.68 – 1.63 (m, 3H), 1.62 – 1.58 (m, 3H), 1.54 (d, J =5.8 Hz, 6H), 1.37 (d, J = 6.7 Hz, 3H), 1.31 (d, J = 6.8 Hz, 3H), 1.23 (d, J =7.0 Hz, 3H), 1.19 – 1.11 (m, 6H), 0.88 (d, J = 6.8 Hz, 3H), -0.35 (d, J =11.8 Hz, 1H), -0.84 (d, J = 11.3 Hz, 1H). 13 C NMR (75 MHz, C6D6, 25 °C, ppm): d = 165.5, 164.6, 163.2, 162.3 (CNCH3), 146.3, 144.9, 144.2, 142.6 (2C),142.1, 126.1, 125.7, 125.2, 124.0, 123.5, 123.4 (aryl), 100.3, 96.6 (β-CH),65.9, 63.4 (ring-CH), 37.6, 37.0 (ring-CH2), 33.9, 32.3, 31.1, 29.2 (CHCH3),27.7, 27.4 (ring-CH2), 26.5, 25.7, 25.6, 25.2 (CH3CN) , 25.0, 24.9 (2C), 24.8,24.5, 24.2 (2C), 23.8 (CH3CH), 20.4 (CH2Si), 3.9 (CH3Si, 3C); IR (KBr pellet,cm -1 ): n= 3059 (w), 2959 (w), 2864 (w), 1910 (m), 1624 (s), 1555 (s), 1503 (w), 1435 (m), 1310 (m), 1246 (s), 1180 (s), 1101 (m), 1042 (w), 1024 (m),935 (s), 862 (vs), 787 (s), 696 (m), 609 (w); Anal. Calc. for C 44 H 69 N4h (771.0368): C, 68.54; H, 9.02; N, 7.27. Found: C, 68.65; H, 8.99; N, 7.22%; as Figure 6 The crystal structure of {Cy[NC(Me)CHC(Me)NAr]2}YCH2SiMe3(4) is shown in Figure 2. Figure 7 and 8 The corresponding compound is {Cy[NC(Me)CHC(Me)NAr]2}YCH2SiMe3(4) 1 H NMR spectra and 13 C NMR spectrum.

[0040] This application also provides an embodiment: The trivalent rare earth metal alkyl containing a chiral bridged diimino group in the specific embodiment 1 can be used as a catalyst to catalyze the intramolecular and intermolecular hydroamination reaction of compounds containing unsaturated carbon bonds. The hydroamination reaction is an important method for forming carbon-nitrogen bonds and is an atom-economic reaction that complies with green chemistry.

[0041] In this example, a chiral bridged diimide rare earth metal complex {Cy[NC(Me)CHC(Me)NAr]2}DyCH2SiMe3 (Cy=(1R,2R)-1,2-cyclohexyl, Ar=2,6- i Pr2C6H3) (1); {Cy[NC(Me)CHC(Me)NAr]2}ErCH2SiMe3 (2); {Cy[NC(Me)CHC(Me)NAr]2}YbCH2SiMe3(3); {Cy[NC(Me)CHC(Me)NAr]2}YCH2SiMe3(4) are catalysts that catalyze intramolecular hydroamination / cyclization reactions of enamines.

[0042] The intramolecular hydroamination / cyclization reactions of enamines are all carried out in Young NMR tubes. Operate in a glove box, add 1 equivalent of enamine, 0.1 equivalent of ferrocene as internal standard, 0.6 mL of C6D6 as solvent, take a certain amount of pentacoordinated mononuclear rare earth hydrocarbon {Cy[NC(Me)CHC(Me)NAr]2}RECH2SiMe3[RE = Dy(1), Er(2), Yb(3), Y(4)] containing chiral cyclohexanediamine bridged bis-β-diimine ligand as catalyst, and then perform NMR tracking reaction. The reaction products can be separated by column chromatography or thin layer chromatography.

[0043] Table 1 Hydroamination / cyclization of aminoalkenes catalyzed bycomplexes 1-4*

[0044] At room temperature, chiral alkyl rare earth complexes {Cy[NC(Me)CHC(Me)NAr]2}RECH2SiMe3[RE = Dy(1), Er(2), Yb(3), Y(4)] can catalyze the conversion of enamine substrates to generate corresponding cyclic amines by hydroamination / cyclization. The amount of catalyst used has an effect on the conversion rate of the substrate. In the experiment, a very good conversion rate was obtained by using a 3% catalyst amount. The reaction temperature also has a significant effect on the conversion rate of the substrate. Under the same conditions, the conversion rate was only 82% at a low temperature of 10℃ for 3h, while the conversion rate reached 97% at room temperature for 1h. At room temperature, under the same catalyst and dosage conditions, the conversion rate of the five-membered ring can reach more than 90% after 1h of reaction, while the formation of the six-membered ring requires 48h of reaction to obtain a similar conversion rate. The formation of the six-membered ring is obviously more difficult than that of the five-membered ring. This experimental result is consistent with Baldwin's law of ring closure.

[0045] In summary, the specific embodiment 1 discloses the synthesis of three chiral bridged diimine compounds Cy[NHC(Me)CHC(Me)NAr]2 (Cy=(1R,2R)-(-)-1,2-cyclohexyl, Ar=2,6-Me2C6H3 (H2L 1 );Ar=2,6-Et2C6H3(H2L 2 ); Ar=2,6- i Pr2C6H3 (H2L 3 )) and H2L 3A series of trivalent rare earth metal alkyl compounds {Cy[NC(Me)CHC(Me)NAr]2}RECH2SiMe3[RE = Dy(1), Er(2), Yb(3), Y(4)] containing chiral bridged diimino groups were successfully synthesized by alkyl elimination reaction of the ligands with trialkyl rare earth complexes RE[CH2SiMe3]3(THF)2. The obtained complexes were fully characterized by spectroscopy, such as Figure 7 and 8 , and its X-ray structure was determined.

[0046] In the complex described in Specific Example 1, each central metal is connected to four nitrogen atoms of the ligand to form a chelate structure centered on the rare earth metal. The synthesized series of trivalent rare earth metal alkyl compounds containing chiral bridging diimino groups {Cy[NC(Me)CHC(Me)NAr]2}RECH2SiMe3[RE = Dy(1), Er(2), Yb(3), Y(4)] are sensitive to air and water and have good solubility in various polar and non-polar organic solvents, such as n-hexane, toluene, and tetrahydrofuran.

[0047] The catalytic activity of this type of monoalkyl chiral rare earth complexes on the intramolecular hydroamination / cyclization reaction of enamines was further studied. The results showed that this type of complex can catalyze the conversion of enamine substrates to undergo hydroamination / cyclization reactions to generate corresponding cyclic amines. The heterocyclic compounds are mainly Markovnikov addition products. Different central metal catalysts have little effect on the conversion rate of the substrate. When the catalyst dosage reaches 3%, a conversion rate of more than 90% can be obtained.

[0048] The above disclosures are only several specific implementation scenarios of the present application, but the present application is not limited thereto, and any changes that can be thought of by a person skilled in the art should fall within the protection scope of the present application. The above application numbers are only for description and do not represent the advantages and disadvantages of the implementation scenarios.

Claims

1. A trivalent rare earth metal alkyl containing a chiral bridging diimino group, characterized in that: include: Each central metal in the trivalent rare earth metal alkyl compound containing a chiral bridging diimino group is connected to four nitrogen atoms of the ligand to form a chelate structure centered on the rare earth metal; and It is sensitive to air and water and is soluble in both polar and non-polar organic solvents.

2. The trivalent rare earth metal alkyl compound containing a chiral bridging diimino group according to claim 1, characterized in that: The trivalent rare earth metal alkyl compound containing a chiral bridging diimino group comprises: {Cy[NC(Me)CHC(Me)NAr]2}RECH2SiMe3[RE = Dy(1), Er(2), Yb(3), Y(4)]; their molecular formulas are: ;or, ;or, ;or, 。 3. The trivalent rare earth metal alkyl compound containing a chiral bridging diimino group according to claim 1, characterized in that: The polar and non-polar organic solvents include: One or more of n-hexane, toluene and tetrahydrofuran.

4. A method for preparing a trivalent rare earth metal alkyl compound containing a chiral bridged diimino group according to any one of claims 1 to 3, characterized in that: include: (1R,2R)-(-)-1,2-cyclohexanediamine, 2,6-diisopropylaniline acetone imine and a catalytic amount of p-toluenesulfonic acid are stirred and heated under reflux overnight in a toluene solution, and water and toluene produced during the reaction are azeotropically separated; After the reaction was completed, the toluene was removed by rotary evaporation, and the remaining thick material was mixed with n-hexane for crystallization to obtain: Cy[NHC(Me)CHC(Me)NAr]2 (Cy=(1R,2R)-(-)-1,2-cyclohexyl, Ar=2,6- i Pr2C6H3)(H2L 3 ); At room temperature, 3 A diimino trivalent rare earth metal alkylate is added to the n-hexane solution, the reaction is stirred, and the solvent is removed under reduced pressure. The residue is dissolved in n-hexane, and the extract is filtered into a single-necked bottle and placed in an environment of 0°C to obtain a complex containing a chiral bridged diimino trivalent rare earth metal alkylate.

5. The method for preparing a trivalent rare earth metal alkyl compound containing a chiral bridged diimino group according to claim 4, characterized in that: The diimino trivalent rare earth metal alkyl compound comprises: Dy III [CH2SiMe3]3(THF)2, Er III [CH2SiMe3]3(THF)2、Yb III [CH2SiMe3]3(THF)2 and Y III [CH2SiMe3]3(THF)2.

6. The method for preparing a trivalent rare earth metal alkyl compound containing a chiral bridged diimino group according to claim 4, characterized in that: Also includes: (1R,2R)-(-)-1,2-cyclohexanediamine, 2,6-dimethylaniline acetylacetonimide and a catalytic amount of p-toluenesulfonic acid are stirred and heated under reflux overnight in a toluene solution, and the water and toluene produced in the reaction process are azeotropically separated; After the reaction is completed, the toluene is removed by rotary evaporation, and the remaining thick substance is mixed with hexane and crystallized to obtain: Cy[NHC(Me)CHC(Me)NAr]2 (Cy=(1R,2R)-(-)-1,2-cyclohexyl, Ar=2,6-Me2C6H3)(H2L 1 )。 7. The method for preparing a trivalent rare earth metal alkyl compound containing a chiral bridged diimino group according to claim 4, characterized in that: Also includes: (1R,2R)-(-)-1,2-cyclohexanediamine, 2,6-diethylaniline acetylacetonimide and a catalytic amount of p-toluenesulfonic acid are stirred and heated under reflux overnight in a toluene solution, and water and toluene generated in the reaction process are azeotropically separated; After the reaction is completed, the toluene is removed by rotary evaporation, and the remaining thick substance is mixed with n-hexane and crystallized to obtain: Cy[NHC(Me)CHC(Me)NAr]2 (Cy=(1R,2R)-(-)-1,2-cyclohexyl, Ar=2,6-Et2C6H3)(H2L 2 )。 8. Use of a trivalent rare earth metal alkyl compound containing a chiral bridged diimino group as claimed in any one of claims 1 to 3, characterized in that: include: As a catalyst for intramolecular and intermolecular hydroamination reactions of compounds containing unsaturated carbon bonds.

9. The use according to claim 8, characterized in that: include: The intramolecular hydroamination / cyclization reactions of the unsaturated carbon bond-containing compounds are all carried out in a Young NMR tube; Sequentially add 1 equivalent of an unsaturated carbon bond-containing compound, 0.1 equivalent of ferrocene as an internal standard, and 0.6 mL of C6D6 as a solvent to a Young NMR tube, take a set dose of the trivalent rare earth metal alkyl containing a chiral bridged diimino group as a catalyst, and then perform a NMR tracking reaction; At room temperature, the trivalent rare earth metal alkyl compound containing a chiral bridging diimino group catalyzes the substrate conversion of the compound containing an unsaturated carbon bond to undergo a hydroamination / cyclization reaction to generate a corresponding cyclic amine.

10. The use according to claim 8, characterized in that: include: When the trivalent rare earth metal alkylate containing chiral bridged diimino group is used as a catalyst, its usage amount is greater than 3%.

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