A carborane skeleton macrocyclic molecule and a synthesis method and application thereof

Abstract

The application provides a carborane skeleton macrocyclic molecule and a synthesis method and application thereof, and belongs to the technical field of organic synthesis. The application comprises the following steps: at room temperature, a compound I is reacted with n-butyllithium in an inert atmosphere to obtain a compound II; after 2 hours, CS2 is added to react to obtain a compound III; after 6 hours, a compound IV is added to react, so that a target compound is obtained. Compared with the prior art, the application significantly enriches the structural diversity of supramolecular macrocycles. The compound has a significant adsorption effect on chlorinated volatile organic compounds (CVOCs).

Description

Technical Field

[0001] This invention relates to the field of organic synthesis technology, and in particular to a carborane skeleton macrocyclic molecule, its synthesis method, and its applications. Background Technology

[0002] More than half a century has passed since Pederson's groundbreaking discovery of the host molecule for synthesis (J.Am. Chem. Soc. 1967, 89, 2495-2496). Today, macrocyclic chemistry, a branch of supramolecular chemistry, has developed into a mature discipline (Coordin. Chem. Rev. 2023, 493, 215256). This field encompasses a variety of molecular systems, including cyclodextrins, crown ethers, columnar aromatics, cucurbiturates, and calixarnes, while new macrocyclic compounds continue to emerge. Currently, an increasing number of functional supramolecular assembly systems are being developed and studied, with applications expanding to catalysis, molecular motors, nanomedicine, sensing, and many other fields. Although these systems are mature and their preparation processes are well-developed, limitations such as the limited types of synthetic reactions and the convergence of molecular structures still exist, severely restricting the structural diversity and application scope of macrocyclic compounds. In recent years, carboranes have attracted widespread attention in the field of supramolecular chemistry due to their abundant reaction sites and unique three-dimensional aromaticity.

[0003] Carboranes, due to their unique geometry and electronic structure, have been widely used in functional materials (Chem. Rev. 2016, 116, 14307-14378), organometallic / coordination chemistry (J. Am. Chem. Soc. 2022, 144, 8371-8378), and drug discovery (Chem. Rev. 2021, 431, 213684). In recent years, significant progress has been made in the construction of macrocyclic molecules based on carborane units. For example, researchers have demonstrated that carborane-based macrocyclic molecules prepared through BH bond activation reactions mediated by noble metals (such as iridium (Ir), rhodium (Rh), and palladium (Pd)) exhibit excellent host-guest properties (J. Am. Chem. Soc. 2020, 142, 8532-8853). Furthermore, combining hydrophobic o-carboranes with aggregation-induced emission (AIE) groups (tetraphenylene) successfully prepared cationic cyclic p-phenylenes with Z-shaped cavities (Chinese. Chem. Lett. 2024, 35, 110074). Another study embedded o-carboranes into the cyclic p-phenylene (CPPs) framework to construct a "necklace-like" macrocyclic structure (Angew. Chem. Int. Ed. 2023, 62, e202213470). While these strategies have significant research value and practical applications, they still have many limitations, such as the reliance on single preparation methods, dependence on specific molecular skeletons and functional groups, and complex reaction conditions. Despite the great potential of this strategy, mild and novel methods for constructing carborane macrocyclic molecules remain to be developed.

[0004] Chlorinated volatile organic compounds (CVOCs) are widely recognized as a class of highly toxic and persistent air pollutants. Among them, dichloromethane (DCM), due to its widespread use and high volatility, has become a key component of this class of pollutants. Therefore, the removal of DCM has become a critical environmental issue, urgently requiring effective solutions.

[0005] In summary, existing methods for synthesizing carborane macrocyclic molecules require the use of toxic compounds and involve complex reaction conditions, resulting in shortcomings in terms of economy and environmental friendliness. Furthermore, the application prospects of carborane macrocyclic molecules are not yet fully explored. Given the possibility of weak interactions in the macrocyclic compounds we studied, we envision utilizing this unique bonding behavior to achieve the separation of dichloromethane. Therefore, developing new methods for synthesizing carborane macrocyclic molecules and their related applications is of great significance. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a carborane-based macrocyclic molecule and its synthetic method. Carborane itself, or with a suitable superbase, can undergo a hydrogen-extracting reaction to yield a nucleophilic carborane anion, which, under appropriate conditions, can undergo nucleophilic addition reactions with suitable compounds. Using this strategy, various electron-deficient compounds, such as benzyl bromide, carbon dioxide, CS2, isothiocyanates, and paraformaldehyde, can be readily modified onto carborane without the use of catalysts. Furthermore, the adsorption of dimethyl cyanide (DCM) is achieved through intermolecular interactions. This method provides a simple, efficient, economical, and green synthetic route for the functionalization of carborane skeletons.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] In a first aspect, the present invention provides a carborane macrocyclic molecule with the following V-structure:

[0009]

[0010] V

[0011] R1 is one of -H, -OMe (methoxy), or -4-Py (4-pyridyl); R2 is one of -H, -OMe, or -4-Py. R1 and R2 can be the same or different.

[0012] Furthermore, R1 = R2 = -H.

[0013] Furthermore, R1 = -H, R2 = -OMe.

[0014] Furthermore, R1 = -4-Py, R2 = -H.

[0015] Furthermore, R1 = -4-Py, R2 = -OMe.

[0016] In a second aspect, the present invention provides a method for synthesizing the carborane skeleton macrocyclic molecule described in the first aspect, comprising:

[0017] (1) The steps for reacting compound I with n-butyllithium (n-BuLi) to obtain compound II:

[0018]

[0019] I II;

[0020] (2) The steps for reacting compound II with CS2 to obtain compound III:

[0021]

[0022] II III;

[0023] (3) The steps for obtaining target compound V by nucleophilic addition reaction of compound III and compound IV:

[0024]

[0025] III IV V

[0026] Furthermore, the reaction is carried out using a one-pot process.

[0027] Furthermore, the molar ratio of compound I, n-butyllithium, CS2 and compound IV is 1.0:2.2:2.4:1.0.

[0028] Furthermore, in step (1), the reaction is carried out in an inert atmosphere.

[0029] Furthermore, in step (3), the nucleophilic addition reaction is carried out in the presence of ultra-dry tetrahydrofuran solvent.

[0030] Thirdly, the present invention provides an application of a carborane-based macrocyclic molecule in the adsorption of halogen compounds.

[0031]

[0032] Furthermore, the halogen compound is DCM (CH2Cl2).

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0034] This invention provides a method for synthesizing a carborane-based macrocyclic molecule without the need for catalysts or transition metals, under room temperature conditions. The method for synthesizing this carborane-based macrocyclic molecule is characterized by readily available raw materials, simple operation, mild reaction conditions, economy, and environmental friendliness. Compared with existing macrocyclic molecules, this macrocyclic molecule has significant application value in the field of CVOCs adsorption. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the embodiments will be briefly described below.

[0036] Figure 1 The diagram shows the synthetic route of the carborane skeleton macrocyclic molecule and the adsorption diagram of CVOCs in a specific embodiment of the present invention.

[0037] Figure 2 This is an XRD single-crystal diffraction structure diagram of V-1, a macrocyclic molecule with a carborane skeleton, in a specific embodiment of the present invention.

[0038] Figure 3This is a diffusion-ordering NMR image of the host-guest complex formed by the carborane skeleton macrocyclic molecule V-4 and DCM in a specific embodiment of the present invention. Detailed Implementation

[0039] The present application will be further described below with reference to specific embodiments.

[0040] It should be noted that terms such as "upper", "lower", "left", "right", and "middle" used in this specification are only for clarity of description and are not intended to limit the scope of implementation. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered as within the scope of this application.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the term “and / or” as used herein includes any and all combinations of one or more of the associated listed items.

[0042] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0043] As used herein, the term “about” is used to provide for the flexibility and imprecision associated with a given term, measure, or value. Those skilled in the art can readily determine the degree of flexibility for a particular variable.

[0044] As used herein, the term “at least one of…” is intended to be synonymous with “one or more of…”. For example, “at least one of A, B, and C” explicitly includes only A, only B, only C, and combinations thereof.

[0045] This invention provides a method for synthesizing a carborane skeleton macrocyclic molecule, comprising the following steps:

[0046] At room temperature, compound I reacts with n-butyllithium in an inert atmosphere to give compound II;

[0047]

[0048] I II

[0049] Two hours later, CS2 was added and the reaction yielded compound III.

[0050]

[0051] III

[0052] After 6 hours, compound IV was added under an inert atmosphere to undergo a nucleophilic addition reaction to obtain the target compound;

[0053]

[0054] IV

[0055] In Formula IV, R1 is one of -H, -OMe, and -4-Py; R2 is one of -H, -OMe, and -4-Py.

[0056] In this invention, after the nucleophilic addition reaction is completed, silica gel chromatography separation is further included. The stationary phase for silica gel chromatography separation is silica; the mobile phase for silica gel chromatography separation is DCM or a mixture of DCM; the DCM mixture is a mixture of DCM and petroleum ether or DCM and methanol, wherein the volume ratio of DCM to petroleum ether is 5~10:1; and the volume ratio of DCM to methanol is 80~100:1.

[0057] This invention does not have any special limitations on the source of the reagents and compounds used; conventional sources are acceptable.

[0058] Example 1

[0059] according to Figure 1 The synthetic route shown below is used to synthesize the target compound V-1. The specific steps are as follows:

[0060] In a pre-dried reaction tube, compound I (0.1 mmol) and ultra-dry tetrahydrofuran (1 mL) were added under nitrogen protection, followed by slow dropwise addition of n-butyllithium (0.22 mmol) at room temperature. After reacting at room temperature for 1 hour, CS2 (0.24 mmol) was slowly added, and stirring continued at room temperature for 6 hours. Then, dibenzyl bromide compound IV-1 (0.1 mmol) was added and stirred for 12 hours. The reaction mixture was then subjected to vacuum distillation and silica gel chromatography (stationary phase: SiO2, mobile phase: DCM and petroleum ether, volume ratio 5-10:1; the product was obtained by vacuum distillation after collection) to obtain the target compound V-1. Compound V-1 was dissolved in DCM and slowly evaporated to obtain crystals of the target compound. Figure 2 ).

[0061]

[0062] I IV-1 V-1

[0063] The structural verification experimental data are as follows:

[0064] Orange solid. Yield: 0.043 mmol, 34.4 mg, 43% yield. 1H NMR (500 MHz, CDCl3) δ 7.17 (d, J = 12.8 Hz, 8H), 4.20 (s, 8H), 3.14 - 2.17 (m, 20H). 13 CNMR (126 MHz, CDCl3) δ 219.3, 133.3, 129.8, 48.3, 44.4. 11 B NMR (160 MHz inCDCl3) δ -13.28, -15.53. IR (neat): 2927, 2625, 2362, 1600, 1467, 1380, 1091,903, 724, 649 cm -1 . HRMS (ESI-TOF / MS): m / z [M+H] + calcd for C 24 H 37 B 20 S5 + :798.2656; found: 798.2656.

[0065] The obtained compound was verified to be compound V-1.

[0066] Example 2

[0067] according to Figure 1 The synthetic route shown below is used to synthesize the target compound V-2. The specific steps are as follows:

[0068] In a pre-dried reaction tube, compound I (0.1 mmol) and ultra-dry tetrahydrofuran (1 mL) were added under nitrogen protection, followed by slow dropwise addition of n-butyllithium (0.22 mmol) at room temperature. After reacting at room temperature for 1 hour, CS2 (0.24 mmol) was slowly added, and stirring continued at room temperature for 6 hours. Then, dibenzyl bromide compound IV-2 (0.1 mmol) was added and stirred for 12 hours. The reaction mixture was then subjected to vacuum distillation and silica gel chromatography (stationary phase: SiO2, mobile phase: DCM and petroleum ether, volume ratio 5-10:1; the product was obtained by vacuum distillation after collection) to obtain the target compound V-2.

[0069]

[0070] I IV-2 V-2

[0071] The structural verification experimental data are as follows:

[0072] Orange solid. Yield: 0.038 mg, 32.5 mg, 38% yield.1 H NMR (500 MHz, CDCl3)δ 7.19 (d, J = 7.7 Hz, 2H), 6.81 (d, J = 7.8 Hz, 2H), 6.76 (s, 2H), 4.29 (s,4H), 4.26 (s, 4H), 3.81 (s, 6H), 3.23 - 2.11 (m, 20H). 13 C NMR (126 MHz, CDCl3) δ 218.1, 158.0, 135.0, 131.3, 121.8, 121.5, 111.5, 45.0, 39.8, 14.2. 11 B NMR (160 MHz in CDCl3) δ -9.84, -11.77, -13.28. IR (neat): 2922, 2852,2610, 1461, 1267, 1173, 1086, 951, 713 cm -1 Anal. Calcd for C 26 H 40 B 20 O2S8 (M =857.28): C, 36.43; H, 4.70; S, 29.92. Found: C, 36.54; H, 4.67; S, 30.08.

[0073] The obtained compound was verified to be compound V-2.

[0074] Example 3

[0075] according to Figure 1 The synthetic route shown below synthesizes compound V-3. The specific steps are as follows:

[0076] In a pre-dried reaction tube, compound I (0.1 mmol) and ultra-dry tetrahydrofuran (1 mL) were added under nitrogen protection, followed by slow dropwise addition of n-butyllithium (0.22 mmol) at room temperature. After reacting at room temperature for 1 hour, CS2 (0.24 mmol) was slowly added, and stirring continued at room temperature for 6 hours. Then, dibenzyl bromide compound IV-3 (0.1 mmol) was added and stirred for 12 hours. The reaction mixture was then subjected to vacuum distillation and silica gel chromatography (stationary phase: SiO2, mobile phase: DCM and methanol, volume ratio 100:1; the product was obtained by vacuum distillation after collection) to give compound V-3.

[0077]

[0078] I IV-3 V-3

[0079] The structural verification experimental data are as follows:

[0080] Orange solid. Yield: 0.034 mg, 32.4 mg, 34% yield. 1 H NMR (300 MHz, CDCl3)δ 8.66 (t, J = 4.5 Hz, 4H), 7.44 - 7.29 (m, 4H), 7.25 - 7.15 (m, 6H), 4.39 -4.30 (m, 4H), 4.28 - 4.17 (m, 4H), 3.57 - 1.94 (m, 20H). 13 C NMR (126 MHz, CDCl3) δ 216.7, 216.0, 150.0, 147.5, 140.6, 134.5, 134.3, 131.3, 131.1,130.8, 130.7, 129.8, 129.8, 123.9, 43.6, 43.6, 42.1, 42.1. 11 B NMR (160 MHz inCDCl3) δ -10.78, -13.67. IR (neat): 2931, 2607, 2292, 1543, 1376, 1091, 903,735, 681 cm -1 HRMS (ESI-TOF / MS): m / z [M] + calcd for C 34 H 42 B 20 N2S8 + : 952.3188;found: 952.3149.

[0081] The obtained compound was verified to be compound V-3.

[0082] Example 4

[0083] according to Figure 1 The synthetic route shown below synthesizes compound V-4. The specific steps are as follows:

[0084] In a pre-dried reaction tube, compound I (0.1 mmol) and ultra-dry tetrahydrofuran (1 mL) were added under nitrogen protection, followed by slow dropwise addition of n-butyllithium (0.22 mmol) at room temperature. After reacting at room temperature for 1 hour, CS2 (0.24 mmol) was slowly added, and stirring continued at room temperature for 6 hours. Then, dibenzyl bromide compound IV-4 (0.1 mmol) was added and stirred for 12 hours. The reaction mixture was then subjected to vacuum distillation and silica gel chromatography (stationary phase: SiO2, mobile phase: DCM and methanol, volume ratio 100:1; the product was obtained by vacuum distillation after collection) to give compound V-4.

[0085]

[0086] I IV-4 V-4

[0087] The structural verification experimental data are as follows:

[0088] Yellow solid. Yield: 0.031 mmol, 31.4 mg, 31% yield. 1 H NMR (500 MHz, CD2Cl2) δ 8.51 (d, J = 5.1 Hz, 4H), 7.16 (d, J = 5.3 Hz, 6H), 6.88 (s, 2H), 4.31 (d, J = 4.4 Hz, 4H), 4.19 (d, J = 4.1 Hz, 4H), 3.80 (s, 5H), 3.00 - 1.97 (m, 20H). 13 C NMR (126 MHz, CD2Cl2) δ 217.7, 216.2, 158.0, 149.3, 147.8,132.8, 132.4, 132.2, 124.2, 122.6, 112.8, 56.0, 43.0, 39.4, 13.8. 11 B NMR (160MHz in CDCl3) δ -10.89, -13.49. IR (neat): 2922, 2609, 2360, 1598, 1314,1078, 735, 568 cm -1 HRMS (ESI-TOF / MS): m / z [M] + calcd for C 36 H 46 B 20 N2O2S8 + :1011.3377; found: 1011.3404.

[0089] The obtained compound was verified to be compound V-4.

[0090] Application examples

[0091] Compound V-4 adsorbs CVOCs compounds

[0092] A 4 mL open sample vial containing 5 mg of solid V-4 (host molecule) without guest molecules was placed in a 10 mL sealed sample vial containing 2 mL of DCM guest molecule solution, and the sealed sample vial was left to stand overnight. Subsequently, solid V-4 was recovered, dried under a nitrogen stream, and its adsorption behavior was characterized by ¹H NMR and diffusion-ordered nuclear magnetic resonance (DOSY) spectroscopy. The obtained compound was confirmed to be the compound shown in Formula VI.

[0093]

[0094] Structural verification experimental data such as Figure 3 As shown, Figure 3 This indicates that DCM forms a host-guest complex with the host molecule V-4, with a diffusion coefficient of D = 4.42 × 10⁻⁶. -6 • cm 2 • S -1 .

[0095] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

[0096] The above embodiments are merely preferred embodiments of the present invention, but the implementation of the present invention is not limited to the above embodiments. Any changes, modifications, substitutions, or combinations made without departing from the spirit and principle of the present invention, such as various combinations of solutions in the embodiments, should be considered equivalent replacements and are all within the protection scope of the present invention.

Claims

1. A carborane-based macrocyclic molecule, characterized in that, It has the following V-structure: ； R1 is one of -H, -OMe, or -4-Py; R2 is one of -H, -OMe, or -4-Py.

2. The carborane macrocyclic molecule as described in claim 1, characterized in that, R1= R2= -H; R1= -H, R2= -OMe; R1= -4-Py, R2= -H; R1= -4-Py, R2= -OMe.

3. A method for synthesizing a carborane skeleton macrocyclic molecule as described in claim 1 or 2, characterized in that, include: (1) The steps for reacting compound I with n-butyllithium to obtain compound II: ； (2) The steps for reacting compound II with CS2 to obtain compound III: ； (3) The steps for obtaining target compound V by nucleophilic addition reaction of compound III and compound IV: 。 4. The method as described in claim 3, characterized in that, The reaction was carried out using a one-pot process.

5. The method as described in claim 3, characterized in that, The molar ratio of compound I, n-butyllithium, CS2 and compound IV is 1.0:2.2:2.4:1.

0.

6. The method as described in claim 3, characterized in that, In step (1), the reaction is carried out in an inert atmosphere.

7. The method as described in claim 3, characterized in that, In step (3), the nucleophilic addition reaction is carried out in the presence of ultra-dry tetrahydrofuran solvent.

8. The application of a carborane skeleton macrocyclic molecule as described in claim 1 or 2 in the adsorption of halogen compounds.

9. The application as described in claim 8, characterized in that, The halogen compound is CH2Cl2.

Images