Ferrocyclopentadiene compounds and preparation methods and applications thereof

Abstract

The present invention discloses an iron heterocyclopentadiene compound having a structure shown in the following formula: #imgabs0# wherein the substituent R is hydrogen or ethyl. The present invention discloses a preparation method of the iron heterocyclopentadiene compound, comprising: dissolving a diyne ligand and [Fe2(CO)9] in toluene, reacting under an inert atmosphere, and then separating and purifying to obtain the iron heterocyclopentadiene compound. The present invention discloses the application of the iron heterocyclopentadiene compound in carbon monoxide slow release. The present invention also discloses the application of the iron heterocyclopentadiene compound in catalytically borohydriding and reducing an aldehyde compound to obtain an organic borate compound. The iron heterocyclopentadiene compound provided by the present invention has a novel structure and a simple preparation process. It can release carbon monoxide at a certain rate under light conditions, and can efficiently and selectively catalyze the borohydriding reduction reaction of an aldehyde compound to prepare an organic borate compound, having a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the field of chemical and pharmaceutical technology, and in particular to a class of iron heterocyclopentadiene compounds with a novel structure, and a preparation method and application thereof. The iron heterocyclopentadiene compounds can be used as a carbon monoxide slow-release agent responsive to light; in addition, the iron heterocyclopentadiene compounds can also be used as an effective catalyst to catalyze the hydroboration reaction of pinacol borane with unsaturated aldehyde compounds to prepare organic borate products with wide industrial applications. Background Art

[0002] Alkyne compounds containing unsaturated triple bonds are widely used and important chemical raw materials and intermediates, and also play an important role in the construction of coordination compounds. The unsaturated bonds of alkynes have various coordination modes when they react with metals: they can form σ-coordinate bonds or π-coordinate bonds; the alkynyl group can be coordinated by end groups, bridges, or half bridges; it can open one or two coordination bonds to coordinate with multiple metal centers, or the ligands can form derivatives and coordinate by carbon-carbon coupling (Coordination Chemistry Reviews, 2017, 350, 217-247; Journal of Organometallic Chemistry, 2014, 751, 111-152). Alkyne compounds have become important ligands for the construction of new metal complexes. On the other hand, transition metal iron carbonyl compounds have gained more and more attention and applications in technical fields such as chemistry, chemical engineering, energy and medicine (Chemical Reviews, 2019, 119, 2550-2610; Chemical Reviews, 2016, 116, 8693-8749; Chemical Reviews, 2019, 119, 2550-2610; Chemical Reviews, 2016, 116, 7043-7077; Coordination Chemistry Reviews, 2021, 429, 213634).

[0003] Through the reaction of alkyne compounds with isotropic precursors ([Fe(CO)5], [Fe2(CO)9], [Fe3(CO) 12 ] etc.), can also obtain iron carbonyl compounds with unique structures (Journal of the American Chemical Society, 1966, 88, 292-301; Synlett, 1993, 924-926; Inorganic Chemistry, 2014, 53, 10674-10684;

[0004] Organometallics, 2022, 41, 2349-2364; Inorganic Chemistry, 2023, 62, 4188-4196). The iron heterocyclopentadiene compounds prepared by the reaction of diyne with [Fe2(CO)9] of the present invention have the following structural characteristics: (1) due to the coordination effect of the conjugated diene, the compound has excellent thermal stability; (2) it contains abundant coordinated carbonyl groups, especially semi-bridged carbonyl groups, which are potential coordinated catalytic centers in the catalytic reaction; these characteristics make this type of iron heterocyclopentadiene compounds have suitable CO release performance and unique catalytic reaction performance. Summary of the invention

[0005] An object of the present invention is to solve at least the above problems and to provide at least the advantages which will be described hereinafter.

[0006] In order to achieve these purposes and other advantages according to the present invention, there is provided an iron heterocyclopentadiene compound having a structure as shown in formula (1):

[0007]

[0008] Wherein, the substituent R is hydrogen or ethyl.

[0009] The present invention also provides a method for preparing the iron heterocyclopentadiene compound, comprising: dissolving a diyne ligand and [Fe2(CO)9] in toluene, reacting under an inert atmosphere, and then separating and purifying to obtain the iron heterocyclopentadiene compound,

[0010]

[0011] Wherein, the substituent R in the iron heterocyclopentadiene compound is hydrogen (ie, compound 1) or ethyl (ie, compound 2).

[0012] Preferably, the diyne ligand is 1,7-octadiyne or 3,9-dodecadiyne.

[0013] The invention also provides application of the iron heterocyclopentadiene compound in the sustained release of carbon monoxide.

[0014] The present invention also provides the use of the iron heterocyclopentadiene compound in catalyzing the hydroboration reduction of aldehyde compounds to obtain organic borate compounds.

[0015]

[0016] Preferably, in the borohydride reduction reaction, the amount of the iron heterocyclopentadiene compound is 0.1 to 2% of the molar amount of the aldehyde compound; the borane is pinacol borane, and the amount is 1.2 to 2 times the molar amount of the aldehyde compound; the reaction solvent is chloroform, the reaction time is 0.5 to 3 hours, and the reaction temperature is 25 to 50°C.

[0017] The present invention has at least the following beneficial effects:

[0018] (1) The structure of the iron heterocyclopentadiene compounds is novel and the preparation process is simple;

[0019] (2) Ferrocyclopentadiene compounds have suitable thermal stability, which is conducive to storage, transportation and application;

[0020] (3) Iron carbonyl compounds of the ferrocyclopentadiene class can release carbon monoxide at a certain rate under light conditions;

[0021] (4) Ferrocyclopentadiene compounds can efficiently and selectively catalyze the hydroboration reduction reaction of aldehyde compounds to prepare organic borate ester compounds, and have broad application prospects in the chemical industry.

[0022] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a characteristic infrared spectrum of compound 1 and compound 2 prepared in the present invention in dichloromethane;

[0024] Figure 2 is a hydrogen nuclear magnetic resonance spectrum of compound 1 prepared in the present invention in deuterated chloroform;

[0025] Figure 3 is the carbon nuclear magnetic resonance spectrum of compound 1 prepared in the present invention in deuterated chloroform;

[0026] Figure 4 is a hydrogen nuclear magnetic resonance spectrum of compound 2 prepared in the present invention in deuterated chloroform;

[0027] Figure 5 is the carbon nuclear magnetic resonance spectrum of compound 2 prepared in the present invention in deuterated chloroform;

[0028] Figure 6 is a schematic diagram of the crystal structure of compound 2 prepared in the present invention;

[0029] Figure 7 This is an infrared spectrum diagram of CO released by compound 2 prepared in the present invention under blue light irradiation; DETAILED DESCRIPTION

[0030] The present invention is described in detail and completely below in conjunction with the accompanying drawings. A person of ordinary skill in the art will be able to implement the present invention based on these descriptions. Before describing the present invention in conjunction with the accompanying drawings, it should be particularly pointed out that the technical solutions and technical features provided in each part of the present invention, including the following description, can be combined with each other without conflict.

[0031] In addition, the embodiments of the present invention involved in the following description are generally only a part of the embodiments of the present invention, rather than all the embodiments. Therefore, based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0032] The present invention provides a method for preparing an azadiene iron carbonyl compound, and the synthesis route thereof is as follows:

[0033]

[0034] Example 1

[0035] Compound 1 Preparation:

[0036] Under argon atmosphere, add [Fe2(CO)9] (0.363g, 1mmol) and toluene solution (10mL) to a dry 100mL Schlenk bottle, add toluene solution (20mL) containing 1,7-octanediyne ligand (0.106g, 1mmol) under stirring at room temperature; stir and reflux the obtained mixture at 110°C for 2 hours in the dark, after the reaction mixture is cooled to room temperature, the solvent is dried under reduced pressure, and the residual black mixture is separated and purified by column chromatography filled with neutral alumina (100-200 mesh) (eluent: petroleum ether). Yield: 0.019g (5%).

[0037] Characterization data of compound 1: FTIR (DCM, ν CO / cm -1 ):2068,2029,1990,1940. 1 H NMR (400MHz, CDCl3, δ / ppm): 6.41 (s, 2H), 2.76 (d, J = 17.2Hz, 2H), 2.40 (d, J = 16.8Hz, 2H), 1.91–1.69 (m, 4H). 13 C NMR (101MHz, CDCl3, δ / ppm): 212.75, 210.06, 207.06, 148.60, 133.54, 29.46, 22.73.

[0038] The infrared spectrum of compound 1 is shown in Figure 1 , H NMR and C NMR spectra are shown in Figure 2 and Figure 3 .

[0039] Example 2

[0040] Compound 2 Preparation:

[0041] Under argon atmosphere, add [Fe2(CO)9] (0.363g, 1mmol) and toluene solution (10mL) to a dry 100mL Schlenk bottle, add toluene solution (20mL) containing 3,9-dodecadiyne (0.162g, 1mmol) under stirring at room temperature; the obtained mixture is stirred and refluxed at 110°C for 2 hours in the dark, after the reaction mixture is cooled to room temperature, the solvent is dried under reduced pressure, and the residual black mixture is separated and purified by column chromatography filled with neutral alumina (100-200 mesh) (eluent: petroleum ether). Yield: 0.035g (8%).

[0042] Characterization data of compound 2: FTIR (DCM, ν CO / cm -1 ):2059,2020,1979,1920. 1 H NMR (400MHz, CDCl3, δ / ppm): δ2.68–2.46(m,6H),2.40(dq,J=15.2,7.6Hz,2H),1.78(dt,J=12.3,7.1Hz,4H),1.11(t,J=7.4Hz,6H). 13 C NMR (101MHz, CDCl3, δ / ppm): 214.75, 211.66, 206.88, 175.88, 130.98, 35.19, 26.23, 22.55, 16.49.

[0043] The infrared spectrum of compound 2 is shown in Figure 1 , H NMR and C NMR spectra are shown in Figure 4 and Figure 5 The absolute structure of this compound was also confirmed by single crystal diffraction experiments, see Figure 6 .

[0044] The present invention also provides an application of an iron heterocyclopentadiene compound as a carbon monoxide slow-release agent.

[0045] Example 3 Study on the release of CO by compound 2 under light

[0046] 6 mg of compound 2 was added to 3 mL of chloroform to dissolve (molar concentration 5 mM); the solution was irradiated with an external LED lamp with a power of 2 watts, and samples were taken at regular intervals to test the infrared spectrum of the samples. Figure 7 It is the CO release process detected by infrared spectroscopy. Figure 7 It can be seen that the carbonyl characteristic absorption peak of compound 2 is constantly decreasing, that is, CO molecules are released. According to the relationship between its absorbance and time, it can be seen that the reaction conforms to first-order kinetics, and the half-life of its CO release (t 1 / 2 ) is 472 minutes, and the apparent rate constant (k obs ) is 1.47 minutes -1 .

[0047] The present invention also provides an application of ferrocyclopentadiene compounds in catalyzing the hydroboration reduction of aldehyde compounds to obtain organic borate compounds.

[0048] Example 4 Wherein the reactant is benzaldehyde, the product is borate, and the product structural formula is:

[0049] Benzaldehyde (0.3 mmol), pinacol borane (0.36 mmol), CDCl3 (0.5 mL), and compound 2 (1 mol%) were added to a pressure bottle (20 mL); stirred at 25°C for 0.5 hours under nitrogen atmosphere to obtain an organic borate compound (yield 51% by NMR detection). NMR data of the product: 1 H NMR (400MHz, CDCl3) δ7.38–7.28(m,5H),4.92(s,2H),1.26(s,12H); 13 C NMR (101MHz, CDCl3) δ139.13,128.27,127.36,126.70,82.98,66.66,24.53.

[0050] Comparative Example 1: Hydroboration Reduction of Benzaldehyde in the Presence of Catalyst Blank

[0051] Benzaldehyde (0.3 mmol), pinacol borane (0.36 mmol) and CDCl3 (0.5 mL) were added into a pressure bottle (10 mL). The mixture was heated and stirred in an oil bath at 25°C under a nitrogen atmosphere for 0.5 h. The hydrogen nuclear magnetic resonance spectrum showed that benzaldehyde did not react.

[0052] The comparison between Comparative Example 1 and Example 4 shows that the iron heterocyclopentadiene compound 2 can effectively catalyze the hydroboration reduction reaction of aldehydes. In addition, the product can also be obtained in a better yield by increasing the amount of pinacol borane, raising the reaction temperature and other conditions.

[0053] Example 5 Wherein the reactant is n-butyraldehyde, the product is borate, and the product structural formula is:

[0054] Add n-butyraldehyde (0.3 mmol), pinacol borane (0.36 mmol), CDCl3 (0.5 mL), and compound 2 (1 mol%) into a pressure bottle (20 mL), and stir at 25°C for 0.5 hours under nitrogen atmosphere to obtain an organic borate compound (yield 99% by NMR detection). NMR data of the product: 11 H NMR (400MHz, CDCl3) δ3.80 (t, J = 6.4Hz, 2H), 1.50 (dd, J = 14.1, 6.8Hz, 2H), 1.33 (dd, J = 14.8, 7.4Hz, 2H), 1.22 (d, J = 6.6Hz, 15H), 0.88 (t, J = 7.3Hz, 3H); 13 C NMR (101MHz, CDCl3) δ82.60, 64.68, 33.54, 24.90, 24.60, 18.77, 13.77.

[0055] Example 6 Wherein the reactant is n-valeraldehyde, the product is borate, and the product structural formula is:

[0056] Add n-valeraldehyde (0.3 mmol), pinacol borane (1.2 mmol), CDCl3 (0.5 mL), and compound 2 (1 mol%) into a pressure bottle (20 mL), and stir at 25°C for 0.5 hours under nitrogen atmosphere to obtain an organic borate compound (yield 99% by NMR detection). NMR data of the product: 1 H NMR (400MHz, CDCl3) δ3.79 (t, J = 6.2Hz, 2H), 1.53 (s, 2H), 1.29 (s, 4H), 1.25–1.15 (m, 12H), 0.85 (s, 3H); 13 C NMR (101MHz, CDCl3) δ82.62, 64.99, 31.18, 24.91, 24.61, 22.42, 14.06.

[0057] Example 7 Wherein the reactant is 1-octanal, the product is borate, and the product structural formula is:

[0058]

[0059] 1-Octanal (0.3 mmol), pinacol borane (0.36 mmol), CDCl3 (0.5 mL), and compound 2 (1 mol%) were added to a pressure bottle (20 mL), and stirred at 25°C for 0.5 hours under a nitrogen atmosphere to obtain an organic borate compound (yield 99% by NMR detection). NMR data of the product: 1 H NMR (400MHz, CDCl3) δ3.79 (t, J = 6.3Hz, 2H), 1.51 (d, J = 6.2Hz, 4H), 1.22 (d, J = 7.1Hz, 20H), 0.83 (d, J = 6.7Hz, 3H); 13 C NMR (101MHz, CDCl3) δ82.59, 64.99, 31.85, 31.48, 29.30, 25.62, 24.59, 22.67, 14.10.

[0060] Example 8 Wherein the reactant is isobutylaldehyde, the product is borate, and the product structural formula is:

[0061] Isobutyraldehyde (0.3 mmol), pinacol borane (0.36 mmol), CDCl3 (0.5 mL), and compound 2 (1 mol%) were added to a pressure bottle (20 mL), and stirred at 25°C for 0.5 hours under a nitrogen atmosphere to obtain an organic borate compound (yield 99% by NMR detection). NMR data of the product: 1 H NMR (400MHz, CDCl3) δ3.58 (d, J = 6.5 Hz, 2H), 1.78 (dt, J = 13.2, 6.6 Hz), 1.23 (d, J = 7.2 Hz, 12H), 0.86 (d, J = 6.7 Hz, 6H); 13 C NMR (101MHz, CDCl3) δ82.61,71.38,29.83,24.91,24.60,18.77.

[0062] Example 9 Wherein the reactant is E-2-pentenal, the product is borate, and the product structural formula is:

[0063] E-2-pentenal (0.3 mmol), pinacol borane (0.6 mmol), CDCl3 (0.5 mL), and compound 2 (1 mol%) were added to a pressure bottle (20 mL), and stirred at 25°C for 3 hours under a nitrogen atmosphere to obtain an organic borate compound (yield 99% by NMR detection). NMR data of the product: 1H NMR (400MHz, CDCl3) δ5.71–5.63(m,1H),5.49(d,J=15.3Hz,1H),4.24(d,J=3.0 Hz,2H),2.02–1.95(m,2H),1.20(dd,J=4.9,1.6Hz,12H),0.93(t,J=7.3Hz,3H); 13 C NMR (101MHz, CDCl3) δ134.49,126.06,82.69,65.45,25.19,24.88,13.34.

[0064] Example 10 Wherein the reactant is benzaldehyde, the product is borate, and the product structural formula is:

[0065] Benzaldehyde (0.3 mmol), pinacol borane (0.6 mmol), CDCl3 (0.5 mL), and compound 2 (1 mol%) were added to a pressure bottle (20 mL), and stirred at 25°C for 3 hours under a nitrogen atmosphere to obtain an organic borate compound (yield 99% by NMR detection). NMR data of the product: 1 H NMR (400MHz, CDCl3) δ7.38–7.28(m,5H),4.92(s,2H),1.26(s,12H); 13 C NMR (101MHz, CDCl3) δ139.13,128.27,127.36,126.70,82.98,66.66,24.53.

[0066] Example 11 Wherein the reactant is 3-chlorobenzaldehyde, the product is borate, and the product structural formula is:

[0067] 3-Chlorobenzaldehyde (0.3mmol), pinacol borane (0.6mmol), CDCl3 (0.5mL), and compound 2 (1mol%) were added to a pressure bottle (20mL), and stirred at 25°C for 3 hours under a nitrogen atmosphere to obtain an organic borate compound (yield 99% by NMR detection). NMR data of the product: 1 H NMR (400MHz, CDCl3) δ7.38(s,2H),5.90(s,1H),5.04(s,1H),4.92(s,2H),1.29(s,12H); 13 C NMR (101MHz, CDCl3) δ141.22,134.19,129.57,127.45,126.74,124.65,83.15,65.87,24.58.

[0068] Example 12 Wherein the reactant is p-chlorobenzaldehyde, the product is borate, and the product structural formula is:

[0069] Add p-chlorobenzaldehyde (0.3 mmol), pinacol borane (0.6 mmol), CDCl3 (0.5 mL), and compound 2 (1 mol%) into a pressure bottle (20 mL), and stir at 25°C for 3 hours under nitrogen atmosphere to obtain an organic borate compound (yield 99% by NMR detection). NMR data of the product: 1 H NMR (400MHz, CDCl3) δ7.28 (dd, J=12.7, 6.7Hz, 2H), 6.98 (t, J=8.5Hz, 2H), 4.85 (s, 2H), 1.24 (s, 12H); 13 C NMR (101MHz, CDCl3) δ135.01,128.47,115.22,115.00,83.08,66.07,24.61.

[0070] Example 13 Wherein the reactant is 4-alkynylbenzaldehyde, the product is borate ester, and the product structure is:

[0071]

[0072] 4-Alkynylbenzaldehyde (0.3mmol), pinacol borane (0.36mmol), CDCl3 (0.5mL), and compound 2 (1mol%) were added to a pressure bottle (20mL), and stirred at 25°C for 0.5 hours under nitrogen atmosphere to obtain an organic borate compound (yield 99% by NMR detection). NMR data of the product: 1 H NMR (400MHz, CDCl3) δ7.49–7.27(m,4H),4.89(s,2H),3.04(s,1H),1.28–1.13(m,12H); 13 C NMR (101MHz, CDCl3) δ139.99,132.03,126.44,121.04,83.51,83.04,77.16,66.16,24.58.

[0073] Example 14 Wherein the reactant is thiophene-2-carboxaldehyde, the product is boric ester, and the product structure is:

[0074] Thiophene-2-carboxaldehyde (0.3 mmol), pinacol borane (0.6 mmol), CDCl3 (0.5 mL), and compound 2 (1 mol%) were added to a pressure bottle (20 mL), and heated and stirred in an oil bath at 50°C for 3 hours under a nitrogen atmosphere to obtain an organic borate compound (yield 99% by NMR detection). NMR data of the product: 1 H NMR (400MHz, CDCl3) δ7.27–7.22(m,1H),7.00(s,1H),6.97–6.91(m,1H),5.03(s,2H),1.25(s,12H); 13 C NMR (101MHz, CDCl3) δ141.90,126.64,125.95,125.58,83.20,61.69,24.68.

[0075] Example 15 Wherein the reactant is furfural, the product is borate, and the product structural formula is:

[0076] Furfural (0.3 mmol), pinacol borane (0.6 mmol), toluene (2 mL), and compound 2 (1 mol%) were added to a pressure bottle (20 mL), and heated and stirred in an oil bath at 50°C for 3 hours under a nitrogen atmosphere to obtain an organic borate compound (yield 99% by NMR detection). NMR data of the product: 1 H NMR (400MHz, CDCl3) δ7.23(d,J=4.9Hz,1H),6.99(d,J=2.3Hz,1H),6.95–6.90(m,1H),5.02(s,2H),1.24(s,12H); 13 C NMR (101MHz, CDCl3) δ141.96,126.59,125.89,125.52,83.14,61.63,24.89.

[0077] Example 16 Wherein the reactant is pyridine-2-carboxaldehyde, the product is borate ester, and the product structural formula is:

[0078] Pyridine-2-carboxaldehyde (0.3 mmol), pinacol borane (0.6 mmol), CDCl3 (0.5 mL), and compound 2 (1 mol%) were added to a pressure bottle (20 mL), and stirred at 25°C for 3 hours under a nitrogen atmosphere to obtain an organic borate compound (yield 99% by NMR detection). NMR data of the product: 1H NMR (400MHz, CDCl3) δ8.49 (d, J = 4.8Hz, 1H), 7.83 (t, J = 7.7Hz, 1H), 7.36 (dd, J = 16.2, 7.6Hz, 2H), 4.96 (s, 2H), 1.17 (d, J = 22.3Hz, 12H); 13 C NMR (101MHz, CDCl3) δ159.58,143.10,139.84,123.47,120.03,80.66,66.22,25.41.

[0079] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. An application of an iron heterocyclopentadiene compound in catalyzing the hydroboration reduction of an aldehyde compound to obtain an organic borate ester compound, wherein the reaction formula of the application is as follows: ； in, The iron heterocyclopentadiene compound has a structure shown in the following formula: ； The aldehyde compound has a structure shown in the following formula: ； The organic borate compound has a structure as shown in the following formula: ； R is hydrogen or ethyl; R' is n-propyl, isopropyl, n-butyl, n-heptyl, 1-butenyl, phenyl, m-chlorophenyl, p-chlorophenyl, p-ethynylphenyl, 2-furyl, 2-thienyl, or 2-pyridyl.

2. The use according to claim 1, characterized in that In the borohydride reduction reaction, the amount of the iron heterocyclopentadiene compound is 0.1-2% of the molar amount of the aldehyde compound; the amount of the pinacol borane is 1.2-2 times the molar amount of the aldehyde compound; the reaction solvent is chloroform, the reaction time is 0.5-3 hours, and the reaction temperature is 25-50°C.

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