A method for preparing two-dimensional chiral graphdiyne by terminal alkyne coupling

Abstract

This invention discloses a method for preparing two-dimensional chiral graphyne via terminal alkyne coupling. The method uses a chiral graphyne framework as the building block and hexaethynylbenzene and chiral terminal alkyne monomers as co-building units. By optimizing the catalytic system (a combination of copper-based catalyst and organic base) and controlling key process parameters such as coupling reaction time, a one-pot in-situ construction of two-dimensional chiral graphyne is achieved. This invention significantly shortens the synthetic route, greatly simplifies the processing steps, and avoids damage to the intrinsic conjugated framework of graphyne during post-modification processes, providing a new approach for obtaining structurally complete and stable two-dimensional chiral graphyne materials.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis technology, specifically a method for preparing two-dimensional chiral graphyne via terminal alkyne coupling. Background Technology

[0002] Graphdiyne (GDY) is a type of phosphine composed of sp and sp. 2 Graphdiyne, a novel allotrope of carbon formed through hybridization, contains benzene rings and 1,3-diyne bonds in its structure. Due to its unique conjugated structure, uniform pore distribution, and excellent semiconductor properties, graphdiyne materials have shown great application potential in various fields such as energy storage (e.g., lithium-ion batteries), electro / photocatalysis, nonlinear optics, and gas separation membranes. Currently, the main methods for preparing graphdiyne materials include: in-situ cross-coupling on copper surfaces, gas / liquid or liquid / liquid interface synthesis, explosive synthesis, and solid-phase synthesis. Graphdiyne derivatives are also prepared using similar methods, requiring the initial preparation of functionalized monomers using organic synthesis techniques, followed by the preparation of the corresponding graphdiyne derivatives using the aforementioned material preparation methods. With increasing demands for material functionalization and differentiated applications, chirality, as an important structural feature, plays an irreplaceable role in many areas such as asymmetric catalysis, chiral separation, circularly polarized light detection, and spintronic devices. However, effectively introducing chiral structures into graphdiyne remains a major research challenge.

[0003] Existing technologies (such as those described in patent CN 118479464 A) employ a modified Hummer method to first prepare graphyne oxide, and then use the oxygen-containing functional groups on its surface for chiral small-molecule post-modification to obtain chiral graphyne derivatives. Similarly, patent CN 116926053 A also utilizes the abundant oxygen-containing functional groups on graphyne quantum dots (GDQDs), introducing chiral groups through post-modification and purifying them using dialysis. All of these methods follow a two-step strategy of "synthesis first, modification later," that is, achieving chiral functionalization through multiple chemical reactions based on the graphyne skeleton prepared by terminal alkyne coupling. However, this route suffers from common problems such as lengthy preparation processes and cumbersome processing steps, and the post-modification process often involves the potential destruction of the intrinsic structure of graphyne.

[0004] Therefore, achieving chiral functionalization of graphyne while preserving its intrinsic structure has become a core challenge in the preparation of chiral graphyne derivatives. While traditional terminal alkyne coupling reactions are technically mature in constructing carbon-carbon triple bonds, effective strategies are still lacking to achieve chiral selectivity control of monomers during assembly. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies that require post-modification to introduce chirality, are lengthy processes, and easily damage the intrinsic structure of graphyne. This invention provides a method for directly preparing two-dimensional chiral graphyne via terminal alkyne coupling. This method uses a chiral graphyne framework as the building block and hexaethynylbenzene and chiral terminal alkyne monomers as co-building units. By optimizing the catalytic system (a combination of copper-based catalysts and organic bases) and controlling key process parameters such as coupling reaction time, a one-pot in-situ construction of two-dimensional chiral graphyne is achieved. Compared to existing technologies, this invention significantly shortens the synthetic route, greatly simplifies the processing steps, and avoids damage to the intrinsic conjugated framework of graphyne during post-modification, providing a new approach for obtaining structurally complete and stable two-dimensional chiral graphyne materials.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for preparing two-dimensional chiral graphyne via terminal alkyne coupling includes the following steps: Step S1: The raw material containing alkyne bonds, the chiral small molecule, the amidation reagent and the first organic base are fully dissolved in an organic solvent and reacted at 25°C for 18-24 hours. Then, the product is separated and purified by column chromatography to obtain the chiral terminal alkyne product. The molar ratio of the alkyne-containing raw material, the chiral small molecule, the amidating reagent, and the first organic base is 1:1:(1~4):(3~6). Add 1-5 mmol of alkynyl-containing raw material per 10 mL of organic solvent; Step S2: Add a copper catalyst and a second organic base to the alkynyl monomer solution and react at 20-200 degrees Celsius for 3-8 hours in an inert atmosphere; The mass ratio of alkynyl monomer, copper catalyst, and second organic base is 4: (2.5~3.5): (3000~4000); Step S3: Add the chiral terminal alkyne product solution dropwise to the reaction solution obtained in the previous step, and continue to maintain for 5-24 h. After a series of treatments such as filtration and washing with organic solvent, the chiral graphyne derivative R / S-GDY can be prepared. The molar ratio of the alkynyl monomer and the chiral terminal alkynyl product required for the reaction solution is 1: (0.3~0.6).

[0007] The alkyne-containing raw material is a carboxylic acid compound containing a carbon-carbon triple bond, specifically p-alkynylbenzoic acid; The chiral small molecule is a chiral compound with an active amino group, specifically (R / S)-1,1,1-trifluoroisopropylamine hydrochloride; The alkynyl monomer is an organic compound containing a carbon-carbon triple bond, specifically hexaethynylbenzene (HEB). The amidating agent is selected from one or more of the following: N,N'-dicyclohexylcarbodiimide (DCC), 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCl), 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate (HATU), benzotriazole-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate (PyBOP), and 1-hydroxybenzotriazole (HOBt).

[0008] The organic solvent is selected from one or more of the following: dichloromethane, chloroform, N,N-dimethylformamide, acetone, toluene, anhydrous ethanol, anhydrous methanol, tetrahydrofuran, or ethyl acetate.

[0009] The copper catalyst is selected from at least one of the following: cuprous chloride, cuprous iodide, cuprous bromide, copper acetate, and copper powder.

[0010] The first organic base and the second organic base may be the same or different, and may be one or more of triethylamine, N,N-diisopropylethylamine, pyridine, N-ethyldiisopropylamine, tetramethylethylenediamine, and 4-dimethylaminopyridine.

[0011] The inert atmosphere is argon, nitrogen, or helium.

[0012] The essential features of this invention are: Currently, in the basic synthesis of graphyne, the deprotected monomer (hexaethynylbenzene) is directly added to an alkaline organic solution, followed by material growth on a copper foil surface. This process mainly utilizes the terminal alkyne coupling reaction catalyzed by the copper surface to construct two-dimensional graphyne. However, due to the lack of effective means to induce and control chiral configurations in this reaction system, and the fact that copper foil surface growth is a heterogeneous catalytic process, it is difficult to provide a chiral selection environment. This results in the product being a chiral graphyne material, making it impossible to directly construct intrinsically chiral structures.

[0013] This invention employs a terminal alkyne coupling method to prepare two-dimensional chiral graphyne derivatives in a one-pot process through the combined action of a copper catalyst and an organic base. The copper catalyst, acting as the active center, first reacts with the terminal alkyne hydrogen in the terminal alkyne monomer to form a copper-acetylide intermediate. The organic base acts as an auxiliary ligand and proton acceptor, promoting the deprotonation process of the terminal alkyne and accelerating the coupling reaction by regulating the electronic properties and spatial environment of the copper center through coordination. Under this synergistic catalytic mechanism, the pre-designed chiral terminal alkyne monomer effectively transfers its chiral configuration to the two-dimensional growth system during the coupling process. By controlling the reaction time, in-situ construction and locking of the chiral structure within the graphyne framework are achieved. The resulting product does not disrupt the intrinsic graphyne framework, exhibits Raman spectra with D and G band peak positions and intensity ratios highly consistent with intrinsic graphyne, and displays a typical symmetrical Cotton effect in its circular dichroism (CD) spectrum, demonstrating a structure-property synergistic optimization effect.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention provides a method for preparing two-dimensional chiral graphyne via terminal alkyne coupling. By designing chiral terminal alkyne molecules, only parameters such as the catalytic system (a combination of copper-based catalyst and organic base) and reaction time need to be controlled to directly construct chiral graphyne derivatives in a one-pot process during the terminal alkyne coupling. Compared with the existing two-step method of "first synthesizing the graphyne substrate and then modifying the chirality," this invention omits the steps of preparing oxidized graphyne, activating oxygen-containing functional groups, post-modifying the chiral molecules, and dialysis purification. This is mainly because this invention uses hexaethynylbenzene and chiral terminal alkyne monomers as co-building units, and the chiral groups directly participate in the in-situ construction of the chiral graphyne skeleton through the terminal alkyne coupling reaction, rather than being attached later. Therefore, there is no need to prepare an achiral graphyne skeleton in advance, nor is it necessary to introduce reaction sites through strong oxidation. This fundamentally avoids the "activation-grafting-purification" process required by the post-modification method. The reaction system contains only the target product and a small amount of unreacted monomers and catalysts, and conventional solvent washing can meet the purification requirements, eliminating the need for time-consuming dialysis techniques.

[0015] This invention features a simple and easy-to-operate process, significantly shortening the synthesis cycle and greatly reducing processing steps. It effectively avoids the synthesis of complex chiral small molecules, preserving the intrinsic structural integrity of graphyne while endowing it with chiral characteristics, making it more suitable for the large-scale preparation of chiral graphyne derivatives. Therefore, this invention opens a new path for constructing high-performance chiral carbon materials suitable for chiral optoelectronics, possessing significant scientific and application value. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the synthetic route for R / S chiral small molecules; Figure 2The CD spectra of the chiral small molecules obtained in Examples 1 and 3 are shown. Figure 3 The 1H NMR spectrum of the R-configuration small molecule obtained in Example 1; Figure 4 The Raman spectrum of intrinsic graphynylene obtained in Example 1; Figure 5 This is a schematic diagram illustrating the synthesis of the chiral graphynylene derivatives obtained in Examples 2 and 3; Figure 6 The Raman spectrum of the chiral graphynylene derivative obtained in Example 2; Figure 7 The CD spectra of the chiral graphynylene derivatives obtained in Examples 2 and 3 are shown. Figure 8 The image shows a scanning electron microscope (SEM) image of the chiral graphyne derivative obtained in Example 2. Figure 9 The 1H NMR spectrum of the S-configuration small molecule obtained in Example 3; Figure 10 The Raman spectrum of the chiral graphynylene derivative obtained in Example 3; Detailed Implementation

[0017] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. The following embodiments are for illustrative purposes only, and the present invention is not limited to these embodiments. Any modifications or equivalent substitutions to the technical solution of the present invention that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the present invention.

[0018] The hexaethynylbenzene of this invention is a known material; the preparation method of hexaethynylbenzene involved in the following examples is as follows: Weigh 120 mg of 1,2,3,4,5,6-hexa((trimethylsilyl)ethynyl)benzene (HEB-TMS) and dissolve it in a two-necked round-bottom flask containing 80 mL of tetrahydrofuran (THF) with stirring. Add 3.5 mL of tetrabutylammonium fluoride (TBAF, 1M) under an inert atmosphere and react at 0 °C for 20–30 min. Hexaacetylenylbenzene (HEB) is obtained after extraction with an organic solvent and evaporation under reduced pressure; however, this method is not limited to this.

[0019] Example 1: Preparation of GDY Step S1: Weigh 3 mmol (438 mg) of p-alkynylbenzoic acid (alkynyl-containing raw material), 3 mmol (449 mg) of (R)-1,1,1-trifluoroisopropylamine hydrochloride, 3.6 mmol of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCl) (EDCl) (690 mg), 3.6 mmol of 1-hydroxybenzotriazole (HOBt) (486 mg), and 9 mmol of N,N-diisopropylethylamine (1.2 g). Add these to a round-bottom flask containing 10 mL of dichloromethane with stirring. The reaction is carried out at room temperature. The reaction progress is monitored by thin-layer chromatography. Prepare a suitable polarity developing solvent (petroleum ether, dichloromethane, ethyl acetate). After concentrating the reaction solution by rotary evaporation, separate and purify the target chiral terminal alkyne product (compound 1) by column chromatography. The obtained compound 1 is a white solid.

[0020] Its synthetic route is as follows Figure 1 As shown, the CD spectrum of compound 1 is as follows: Figure 2 As shown in the spectrum, compound 1 exhibits a negative Cotton effect at 245 nm, confirming its distinct chiral configuration, and its CD spectrum shows a mirror-symmetric distribution with that of compound 2 in Example 3. Figure 2 This mirror symmetry relationship confirms that compound 1 and compound 2 have opposite absolute configurations. This was confirmed using proton nuclear magnetic resonance spectroscopy (NMR). 1 Compound 1 was characterized by 1H NMR, and the results are as follows: Figure 3 As shown, the data is as follows: 1 H NMR (400MHz, CDCl3) δ 7.74 (d, J = 8.5 Hz, 2H), 7.58 (d, J = 8.5 Hz, 2H), 6.10 (d, J = 9.0Hz, 1H), 5.00 – 4.86 (m, 1H), 3.23 (s, 1H), 1.43 (d, J = 7.0 Hz, 3H). The above data are consistent with the structure of target compound 1, confirming the successful synthesis of the chiral terminal alkyne monomer.

[0021] In step S2, 30 mg (0.16 mmol) CuI and 40 mL (31 g, 267 mmol) tetramethylethylenediamine were added to a two-necked flask containing 60 mL of acetone. After deoxygenation, the reaction was carried out under a nitrogen atmosphere. Then, HEB (40 mg, 0.18 mmol) was dissolved in 60 mL of THF and added dropwise to the reaction system at 50 °C. The reaction was carried out for 8 hours. The mass ratio of HEB : CuI : tetramethylethylenediamine was 4 : 3 : 3100.

[0022] Step S3: The upper reaction liquid is then directly filtered, washed with organic solvent, and dried to obtain material GDY. Raman spectroscopy is used to characterize GDY (e.g., ...). Figure 4 Four characteristic peaks were obtained, with the D peak at 1396 cm⁻¹. -1 G peak (1583 cm) -1 ), characteristic peak of alkyne bond vibration (1972 cm⁻¹) -1 2178 cm -1 The peak positions and relative intensities of the four characteristic peaks mentioned above are highly consistent with the typical Raman spectra of graphdiene reported in the literature, confirming that the method successfully prepared graphdiene with complete sp / sp... 2 Intrinsic graphynylene material with a conjugated framework. This Raman spectrum will serve as a control to evaluate the retention of the intrinsic framework in the subsequently prepared one-pot chiral derivative (R / S-GDY) (see Example 2). Figure 6 Example 3, Figure 10 ).

[0023] Example 2: Preparation of chiral derivative R-GDY Step S1 is the same as step S1 in Example 1; Step S2 is the same as step S2 in Example 1; In step S3, compound 1 (20 mg, 0.083 mmol) was dissolved in 40 mL of THF to prepare a compound 1 solution, which was then added dropwise to the reaction system obtained in step S2. After maintaining the reaction for 15 h, the reaction solution was filtered, washed, and dried to obtain the chiral derivative R-GDY. The molar ratio of HEB to compound 1 in step S2 was 1:0.46.

[0024] The synthetic route of R-GDY is as follows: Figure 5 As shown, Raman spectroscopy was used to characterize the structure of R-GDY. Figure 6 The spectrum shows four characteristic peaks: D peak (1398 cm⁻¹). -1 G peak (1582 cm) -1 ) and two characteristic peaks of alkyne bond vibration (1970 cm⁻¹) -12183 cm -1 The peak positions and relative intensities of the above characteristic peaks are similar to those of the intrinsic GDY in Example 1 (). Figure 4 The results are largely consistent, indicating that the R-GDY prepared using the co-construction strategy of this invention fully retains the intrinsic sp / sp of graphyne. 2 Conjugated framework. The chiral characteristics of R-GDY were characterized using CD spectroscopy, and the results are as follows: Figure 7 As shown in the image. The spectrum shows that R-GDY exhibits a negative Cotton effect at 676 nm, confirming its definite chiral configuration. The CD spectrum is compared with that of S-GDY in Example 3. Figure 7 In comparison, the two exhibit mirror-symmetric distributions at the same wavelength—the negative Cotton effect of R-GDY corresponds to the positive Cotton effect of S-GDY. This mirror-symmetry relationship confirms that R-GDY and S-GDY have opposite absolute configurations, indicating that the chiral configuration of the chiral terminal alkyne monomer was successfully transferred to the graphyne framework during construction. The morphology of R-GDY was observed using scanning electron microscopy (SEM), and the results are as follows: Figure 8 As shown, R-GDY exhibits a typical two-dimensional lamellar structure, consistent with the morphological characteristics of graphodyne materials, further confirming that the co-construction strategy did not alter the two-dimensional morphological characteristics of the material. Based on the combined characterization results of Raman spectroscopy, CD spectroscopy, and SEM, this invention successfully prepared R-GDY chiral graphodyne derivatives possessing both intrinsic skeletal integrity and clear chiral characteristics. Compared to the existing two-step process of "first synthesizing the substrate, then modifying the chirality" (as described in patents CN 118479464 A and CN116926053 A), this invention, through the co-construction strategy of hexaethynylbenzene and chiral terminal alkyne monomers, introduces chirality while completely preserving the intrinsic graphodyne skeletal framework (confirmed by Raman spectroscopy), avoiding damage to the framework during the post-modification process, thus demonstrating the feasibility and effectiveness of the co-construction strategy of this invention.

[0025] Example 3: Preparation of chiral derivative S-GDY Step S1 is the same as step S1 in Example 1, except that (R)-1,1,1-trifluoroisopropylamine hydrochloride 3 mmol (449 mg) is replaced with (S)-1,1,1-trifluoroisopropylamine hydrochloride 3 mmol (449 mg). After purification by column chromatography, the chiral terminal alkyne product (compound 2) is obtained. Compound 2 is a white solid. Its synthetic route is as follows: Figure 1 As shown, the CD spectrum of compound 2 is as follows: Figure 2 As shown in the spectrum, compound 2 exhibits a positive Cotton effect at 245 nm, confirming its distinct chiral configuration, and its CD spectrum shows a mirror-symmetric distribution with that of compound 1 in Example 1. Figure 2This mirror symmetry relationship confirms that compound 2 has the opposite absolute configuration to compound 1. The results were obtained using proton nuclear magnetic resonance spectroscopy (NMR). 1 Compound 2 was characterized by 1H NMR, and the results are as follows: Figure 9 As shown, the data is as follows: 1 ¹H NMR (400 MHz, CDCl₃) δ 7.74 (d, J = 8.5 Hz, 2H), 7.58 (d, J = 8.5 Hz, 2H), 6.10 (d, J = 9.0 Hz, 1H), 5.00 – 4.86 (m, 1H), 3.23 (s, 1H), 1.43 (d, J = 7.0 Hz, 3H). These data are consistent with the structure of target compound 2, confirming the successful synthesis of the chiral terminal alkyne monomer.

[0026] Step S2 is the same as step S2 in Example 1; In step S3, compound 2 (20 mg, 0.083 mmol) was dissolved in 40 mL of THF to prepare a compound 2 solution, which was then added dropwise to the reaction system obtained in step S2. After maintaining the reaction for 15 h, the reaction solution was filtered, washed, and dried to obtain the chiral derivative S-GDY. The molar ratio of HEB to compound 2 in step S2 was 1:0.46.

[0027] The synthetic route of S-GDY is as follows: Figure 5 As shown, Raman spectroscopy was used to characterize the structure of S-GDY. Figure 10 The spectrum shows four characteristic peaks: D peak (1398 cm⁻¹). -1 G peak (1582 cm) -1 ) and two characteristic peaks of alkyne bond vibration (1970 cm⁻¹) -1 2183 cm -1 The peak positions and relative intensities of the above characteristic peaks are similar to those of the intrinsic GDY Raman spectrum in Example 1. Figure 4 The results are largely consistent, indicating that the S-GDY prepared using the co-construction strategy of this invention fully retains the intrinsic sp / sp of graphyne. 2 Conjugated framework. Furthermore, its Raman characteristic peak positions and relative intensities are similar to those of R-GDY in Example 2 ( Figure 6 The results are completely consistent, further confirming that this co-construction strategy has good universality and scalability in the preparation of chiral graphdiene. The chiral characteristics of S-GDY were characterized using CD spectroscopy, and the results are as follows: Figure 7 As shown in the spectrum, S-GDY exhibits a positive Cotton effect at 676 nm, confirming its distinct chiral configuration. This is compared to the CD spectrum of R-GDY in Example 2. Figure 7 In comparison, both exhibit mirror-symmetric distributions at the same wavelength. This mirror-symmetry confirms that S-GDY and R-GDY have opposite absolute configurations, indicating that the chiral configuration of the chiral terminal alkyne monomer was successfully transferred to the graphyne framework during construction. Regarding the microstructure, since S-GDY and R-GDY are chiral enantiomers, based on the common knowledge that enantiomers have the same physical properties in achiral environments, it is reasonable to presume that the morphology of S-GDY is consistent with that of R-GDY, i.e., exhibiting a typical two-dimensional lamellar structure (SEM results for R-GDY can be found in...). Figure 8 Based on the above characterization results, this invention successfully prepared an S-GDY chiral graphyne derivative that possesses both intrinsic skeletal integrity and well-defined chiral characteristics. The successful preparation of S-GDY further verifies the feasibility and universality of the proposed strategy of co-constructing hexaethynylbenzene with chiral terminal alkyne monomers, providing a reliable technical path for the controllable construction of chiral graphyne materials.

[0028] Application prospects of R-GDY / S-GDY obtained by this invention: The R-GDY and S-GDY obtained in this invention have the following structural features: (1) The circular dichroism spectrum shows a clear symmetrical Cotton effect ( Figure 7 (2) Raman spectroscopy shows that the characteristic peak positions and intensity ratios of the D and G bands are almost identical to those of intrinsic graphynylene. Figure 4 , Figure 6 , Figure 10 ), confirming that it completely retains the two-dimensional conjugated framework of graphdiene. (3) Scanning electron microscopy (SEM) characterization shows that the obtained material maintains a complete two-dimensional sheet morphology ( Figure 8 R-GDY / S-GDY possesses the basic structural foundation for film formation. Based on these structural characteristics, R-GDY / S-GDY has significant application potential in the following areas: Chiral optoelectronic devices: Utilizing the Cotton effect, selective response to circularly polarized light can be achieved, which can be used to construct circularly polarized light emission / detection devices, chiral light modulators, etc. Chiral biosensing and recognition: By utilizing the differential affinity of chiral microenvironment for enantiomers such as amino acids and drug molecules, combined with the excellent electronic transport properties of graphyne, highly sensitive and selective chiral electrochemical sensors can be constructed.

[0029] Asymmetric catalysis: used as a chiral inducible catalyst or chiral catalyst support for reactions such as asymmetric hydrogenation and asymmetric coupling.

[0030] Chiral separation membranes: Utilizing their two-dimensional sheet structure, separation membranes can be assembled. Combined with the enantiomeric recognition capability provided by the intrinsic chiral environment and the inherent pore transport characteristics of the graphyne skeleton, selective permeation and separation of enantiomeric substances such as amino acids and chiral drugs can be achieved.

[0031] The present invention further illustrates a method for preparing two-dimensional chiral graphodyne by end-acetylation coupling using the above embodiments, but is not limited to specific process steps. Any improvements made to the present invention by other skilled in the art by means of addition or substitution under the inspiration of the present invention shall fall within the protection scope of the present invention.

[0032] Matters not covered in this invention are common knowledge.

Claims

1. A method for preparing two-dimensional chiral graphyne via terminal alkyne coupling, characterized in that, The method includes the following steps: Step S1: The raw material containing alkyne bonds, the chiral small molecule, the amidation reagent and the first organic base are fully dissolved in an organic solvent and reacted at 25 °C for 18-24 hours. Then, the product is separated and purified by column chromatography to obtain the chiral terminal alkyne product. The molar ratio of the alkyne-containing raw material, the chiral small molecule, the amidating reagent, and the first organic base is 1:1:(1~4):(3~6). Add 1-5 mmol of alkynyl-containing raw material per 10 mL of organic solvent; Step S2: Add a copper catalyst and a second organic base to the alkynyl monomer solution and react at 20-200 degrees Celsius for 3-8 hours in an inert atmosphere; The mass ratio of alkynyl monomer, copper catalyst, and second organic base is 4: (2.5~3.5): (3000~4000); Step S3: Add the chiral terminal alkyne product solution dropwise to the reaction solution obtained in the previous step, and continue to maintain for 5-24 h. After filtration and washing, two-dimensional chiral graphyne is prepared. The molar ratio of the alkynyl monomer and the chiral terminal alkynyl product required for the reaction solution is 1: (0.3~0.6). The alkyne-containing raw material is p-alkynylbenzoic acid; The chiral small molecule is (R / S)-1,1,1-trifluoroisopropylamine hydrochloride; The alkynyl monomer is hexaethynylbenzene.

2. The method for preparing two-dimensional chiral graphyne via terminal alkyne coupling as described in claim 1, characterized in that, The amidating agent is one or more of N,N'-dicyclohexylcarbodiimide, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate, benzotriazole-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate, and 1-hydroxybenzotriazole.

3. The method for preparing two-dimensional chiral graphyne via terminal alkyne coupling as described in claim 1, characterized in that, The organic solvent is selected from one or more of the following: dichloromethane, chloroform, N,N-dimethylformamide, acetone, toluene, anhydrous ethanol, anhydrous methanol, tetrahydrofuran, or ethyl acetate.

4. The method for preparing two-dimensional chiral graphyne via terminal alkyne coupling as described in claim 1, characterized in that, The copper catalyst is cuprous chloride, cuprous iodide, cuprous bromide, copper acetate, or copper powder.

5. The method for preparing two-dimensional chiral graphyne via terminal alkyne coupling as described in claim 1, characterized in that, The first organic base and the second organic base may be the same or different, and may be one or more of triethylamine, N,N-diisopropylethylamine, pyridine, N-ethyldiisopropylamine, tetramethylethylenediamine, and 4-dimethylaminopyridine.

6. The method for preparing two-dimensional chiral graphyne via terminal alkyne coupling as described in claim 1, characterized in that, The inert atmosphere is argon, nitrogen, or helium.

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