A stereoselective synthesis method of α-2'-deoxynucleoside and its application

Abstract

The present invention discloses a stereoselective synthesis method and application of α-2′-deoxynucleosides, which utilizes a phosphine oxide group on a glycosyl donor as a remote directing group. By anti-selectivity, the sugar ring β face is shielded so that the glycosyl acceptor can only carry out nucleophilic attack on the anomeric position of the glycosyl donor from the sugar ring α face, thereby achieving stereoselective glycosidation of the opposite side. This method can efficiently control the stereoselectivity and regioselectivity of the glycosidation reaction, especially for the synthesis of nucleoside derivatives in which C-2′ does not have an adjacent group participating group, showing great advantages. The method has mild reaction conditions and is easy to operate. At the same time, anti-proliferation experiments show that the preferred compounds of α-2′-deoxynucleosides have good inhibitory activity against tumor cells such as SH-SY5Y and LN229, and have good application prospects in the anti-tumor field. The present invention is of great help in exploring the potential value of α-configuration nucleosides, nucleotides and even nucleic acids in drug development.

Description

Technical Field

[0001] The present invention relates to chemical synthesis technology, and in particular to a method and application of stereoselective synthesis of α-2′-deoxynucleoside. Background Art

[0002] Nucleosides and 2'-deoxynucleosides, as essential building blocks of RNA and DNA, play a crucial role in modern drug development. Since 2000, at least 20 nucleosides and their analogs have been approved worldwide as antiviral, antibacterial, anticancer, and antiplatelet drugs, including sofosbuvir, a blockbuster drug for the treatment of chronic hepatitis C, and mononuclear virion, the first oral treatment for COVID-19. Many of these drugs, including those containing unnatural L-ribose and 2-deoxy-L-ribose sugars, require critical N-glycosylation to link the ribose or 2-deoxyribose sugar to a base (i.e., purines and pyrimidines) via a glycosidic bond in the natural β-orientation. However, N-glycosylation of bases poses significant challenges to glycochemistry due to multiple factors, including the poor nucleophilicity of the bases and issues with the N7 / N9 regioselectivity of purines. In particular, glycosylation conditions for 2'-deoxyribosyl donors are even more limited due to their high reactivity and easy hydrolysis and elimination.

[0003] Meanwhile, the stereoselective synthesis of non-natural α-nucleosides remains unresolved. Most examples reported to date are merely low-yield byproducts of the β-nucleoside preparation process. Indeed, there is growing interest in exploring the potential biological activities of α-nucleosides and α-oligonucleotides, including antitumor, antiviral, antiretroviral, antibacterial, and antiparasitic activities. Notably, compared to their natural β-counterparts, they generally exhibit greater stability toward enzymes and can sometimes even act as inhibitors. Therefore, incorporation of α-nucleosides into mRNA vaccines and drugs could improve their metabolic stability. Furthermore, similar to natural DNA, two complementary α-oligonucleotide chains can form an antiparallel double helix structure. Hybridization of α-chains with β-chains can produce parallel double helices or even triple helices with high nuclease resistance, potentially offering an alternative approach to addressing stability issues in nucleic acid drug development. Unfortunately, despite the potential high value of α-nucleosides, further research has been hampered by the difficulty in obtaining these compounds. Therefore, the efficient synthesis of single-configuration α-2′-deoxynucleosides holds significant promise for new drug development. Summary of the Invention

[0004] Objectives of the Invention: The present invention aims to provide a method for the direct synthesis of α-2′-deoxynucleosides with high stereoselectivity and yield, addressing the problems of existing methods with poor stereoselectivity and regioselectivity for such glycosidic bonds. Another objective of the present invention is to provide application prospects for the described α-2′-deoxynucleosides.

[0005] Technical solution: The direct synthesis method of α-2′-deoxynucleosides with high stereoselectivity described in the present invention has the following general reaction formula:

[0006]

[0007] Wherein, Formula I is a glycosyl donor;

[0008] R1 is a hydroxyl substituent at position 5; R2 is a hydroxyl substituent at position 3; LG is a leaving group;

[0009] Formula IINu is a glycosyl acceptor, which is divided into purine base and pyrimidine base;

[0010] The catalyst is selected from any one or both of PPh3AuOTf and PPh3AuNTf2;

[0011] Molecular sieves are MS;

[0012] The reaction temperature is -25°C to 50°C.

[0013] The direct synthesis method of α-2′-deoxynucleosides with high stereoselectivity, when the glycosyl acceptor is a purine base, specifically comprises the following steps:

[0014] (1) A glycosyl donor represented by formula I, a glycosyl acceptor represented by formula II, and a molecular sieve are added to an organic solvent under the protection of an inert gas. The reaction system is then placed at -25°C to 50°C, a catalyst is added, and the reaction is carried out. After the reaction is complete, a crude deoxynucleoside product represented by formula III is obtained.

[0015] The method for directly synthesizing α-2′-deoxynucleosides with high stereoselectivity, wherein the glycosyl acceptor is a pyrimidine base, specifically comprises the following steps:

[0016] (1) Silylation: The glycosyl donor represented by Formula I and the glycosyl acceptor represented by Formula II are added to acetonitrile, and then N, O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) is added at 40-60°C. The reaction is carried out under inert gas protection until the solution is clear.

[0017] (2) removing acetonitrile, then placing the reaction system at -25°C to 50°C, adding an organic solvent, a catalyst and a molecular sieve, and reacting. After the reaction is complete, a crude deoxynucleoside product represented by formula III is obtained.

[0018] The method for directly synthesizing α-2′-deoxynucleoside with high stereoselectivity may be followed by the next step: filtering, vacuum concentrating, and column chromatography the crude deoxynucleoside product represented by Formula III to obtain a pure deoxynucleoside product represented by Formula III.

[0019] In the direct synthesis method of α-2′-deoxynucleoside with high stereoselectivity, the glycosyl donor is 2-deoxyribose of furanose type sugar.

[0020] The direct synthesis method of α-2′-deoxynucleosides with high stereoselectivity, wherein R1 in Formula I and Formula III is selected from benzyl (Bn), benzoyl (Bz), tert-butyldiphenylsilyl (TBDPS), 2-diphenylphosphonoacetyl (DPPA), 2-diphenylphosphonopropionyl, 2-diphenylphosphono (DPP), 2-p-tolylsulfonylacetyl, 2-p-tolylsulfonylacetyl;

[0021] R2 is selected from benzyl (Bn), benzoyl (Bz), acetyl (Ac), tert-butyldiphenylsilyl (TBDPS), tert-butyldimethylsilyl (TBS), 2-diphenylphosphonyl (DPP);

[0022] The leaving group LG in formula I is o-alkynyl benzoate;

[0023] Preferably, the leaving group LG is:

[0024]

[0025] The organic solvent is one or more of dichloromethane, toluene, trifluorotoluene, dichloroethane, ether or acetonitrile.

[0026] In the direct synthesis method of α-2′-deoxynucleoside with high stereoselectivity, the molar ratio of the glycosyl donor represented by formula I to the glycosyl acceptor represented by formula II is 1.0-1.2:1-2.0.

[0027] In the direct synthesis method of α-2′-deoxynucleosides with high stereoselectivity, the glycosyl donor shown in formula I is selected from the following compounds shown in any one of the structures I-1 to I-4:

[0028]

[0029] The direct synthesis method of α-2′-deoxynucleoside with high stereoselectivity, wherein Nu in Formula II includes a compound with any structure shown in the following II-1 to II-15:

[0030]

[0031] The direct synthesis method of α-2′-deoxynucleoside with high stereoselectivity, the deoxynucleoside product represented by formula III is selected from the compounds represented by any one of the following structures III-1 to III-28:

[0032]

[0033]

[0034] The compound shown in formula IV and its pharmaceutically acceptable salt:

[0035]

[0036] R1 is 2-diphenylphosphonyl (DPP); R2 is 2-diphenylphosphonyl (DPP);

[0037] Nu is selected from the following groups:

[0038]

[0039] Use of the compound of formula IV and its pharmaceutically acceptable salt in the preparation of a drug for treating central nervous system tumors. Further preferably, the central nervous system tumors include neuroblastoma and glioma.

[0040] The synthesis method is specifically:

[0041] For purinergic receptors:

[0042] (1) Adding a glycosyl donor represented by Formula I, a glycosyl acceptor represented by Formula II, and a freshly activated molecular sieve to an organic solvent, and then placing the reaction system at -25°C to 50°C under the protection of an inert gas, adding a catalyst, and carrying out the reaction;

[0043] (2) After the reaction is complete, the deoxynucleoside product represented by Formula III is obtained by filtration, vacuum concentration, and column chromatography.

[0044] For pyrimidine receptors:

[0045] (1) Silylation: The glycosyl donor of Formula I and the glycosyl acceptor of Formula II are added to MeCN, and then N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) is added at 40-60°C. Under inert gas protection, the reaction is carried out for 30 minutes until the solution becomes clear. It should be noted that this step requires the addition of BSTFA in MeCN at 40-60°C for silylation of pyrimidines before the subsequent reaction, while this step is not required for purines.

[0046] (2) removing MeCN, then placing the reaction system at -25°C to 50°C, adding an organic solvent, a catalyst, and freshly activated molecular sieves, and carrying out the reaction;

[0047] (3) After the reaction is complete, the deoxynucleoside product represented by Formula III is obtained by filtration, vacuum concentration, and column chromatography.

[0048] Furthermore, the glycosyl donor is furanose 2-deoxyribose;

[0049] Further, preferably, the substituent R1 in Formula I and Formula III is 2-diphenylphosphonoacetyl (DPPA) or 2-diphenylphosphono (DPP);

[0050] Furthermore, since some larger silicon-based protecting groups affect the stereoselectivity of glycosidation during the reaction, preferably, the substituent R2 in Formula I and Formula III is benzyl or 2-diphenylphosphonyl (DPP);

[0051] Furthermore, the leaving group (LG) in Formula I was screened, such as N-phenyl-trifluoroacetimidate or o-alkynyl benzoate. N-phenyl-trifluoroacetimidate assembled at the anomeric position of 2-deoxyribose is very unstable and cannot undergo subsequent glycosylation reaction; while o-alkynyl benzoate has mild reaction conditions during the glycosylation process and excellent reaction effect; therefore, the leaving group LG in Formula I is o-alkynyl benzoate.

[0052] Furthermore, the organic solvent is one of dichloromethane, toluene, dichloroethane or acetonitrile, preferably dichloroethane and dichloromethane.

[0053] Furthermore, the reaction temperature is -25°C to 50°C. In the experiment, PPh3AuNTf2 was used as a catalyst and the glycosylation reaction was carried out in dichloroethane. Taking into account the yield, selectivity and experimental operability, preferably, the most suitable temperature is room temperature.

[0054] Further preferably, for purine acceptors, the molar ratio of the glycosyl donor represented by formula I to the glycosyl acceptor represented by formula II is (1.0-1.2): (1-1.5); for pyrimidine acceptors, the molar ratio of the glycosyl donor represented by formula I to the glycosyl acceptor represented by formula II is (1.0-1.2): (1.5-2.0).

[0055] In certain specific embodiments, when the glycosyl donor is a 2-deoxyribose donor of a furanose type sugar, the preparation method of the glycosyl donor is as follows:

[0056]

[0057] Or:

[0058]

[0059] Or:

[0060]

[0061] Or:

[0062]

[0063] In some embodiments, the method for preparing an optimized glycosyl donor comprises the following steps:

[0064] (1) The corresponding glycosyl donor was dissolved in anhydrous DCM, and DBU and diphenylphosphinoyl chloride were added at 0°C. After stirring at room temperature for 2 h, the mixture was quenched with water, concentrated in vacuo, and purified by column chromatography to obtain a glycoside compound with a phosphorus oxide side chain installed at the 5-position.

[0065] (2) Dissolve in 80% AcOH and add SrCl2·6H2O at 50°C. TLC shows the reaction is complete. Adjust the pH to neutral and remove the anomeric methyl group by column chromatography.

[0066] (3) The compound was dissolved in anhydrous DCM, and then EDCI, DMAP, and o-alkynylbenzoic acid were added. The reaction was carried out at room temperature. After completion, the corresponding glycosyl donor was obtained by column chromatography purification.

[0067] In other embodiments, the method for preparing the optimized glycosyl donor comprises the following steps:

[0068] (1) The corresponding glycosyl donor was dissolved in anhydrous DCM, and EDCI and DPPAOH were added. After stirring at room temperature for 1 h, the mixture was quenched with Et3N, concentrated in vacuo, and purified by column chromatography to obtain a glycoside compound with a phosphorus oxide side chain installed at the 5-position.

[0069] (2) Dissolve in 80% AcOH and add SrCl2·6H2O at 50°C. TLC shows the reaction is complete. Adjust the pH to neutral and remove the anomeric methyl group by column chromatography.

[0070] (3) The compound was dissolved in anhydrous DCM, and then EDCI, DMAP, and o-alkynylbenzoic acid were added. The reaction was carried out at room temperature. After completion, the corresponding glycosyl donor was obtained by column chromatography purification.

[0071] In other embodiments, the method for preparing the optimized glycosyl donor comprises the following steps:

[0072] (1) The corresponding glycosyl donor was dissolved in anhydrous DCM, and DBU and 3-diphenylphosphorylpropionic acid were added. After stirring at room temperature for 1 h, the mixture was quenched with Et3N, concentrated in vacuo, and purified by column chromatography to obtain a glycoside compound with a phosphorus oxide side chain installed at the 5-position.

[0073] (2) Dissolve in 80% AcOH and add SrCl2·6H2O at 50°C. TLC shows the reaction is complete. Adjust the pH to neutral and remove the anomeric methyl group by column chromatography.

[0074] (3) The compound was dissolved in anhydrous DCM, and then EDCI, DMAP, and o-alkynylbenzoic acid were added. The reaction was carried out at room temperature. After completion, the corresponding glycosyl donor was obtained by column chromatography purification.

[0075] In other embodiments, the method for preparing the optimized glycosyl donor comprises the following steps:

[0076] (1) The corresponding glycosyl donor was dissolved in anhydrous DCM, and DBU and diphenylphosphinoyl chloride were added. After stirring at room temperature for 5 h, the mixture was quenched with water, concentrated in vacuo, and purified by column chromatography to obtain a glycoside compound with phosphorus oxide side chains installed at the 3 and 5 positions.

[0077] (2) Dissolve in 80% AcOH and add SrCl2·6H2O at 50°C. TLC shows the reaction is complete. Adjust the pH to neutral and remove the anomeric methyl group by column chromatography.

[0078] (3) The compound was dissolved in anhydrous DCM, and then EDCI, DMAP, and o-alkynylbenzoic acid were added. The reaction was carried out at room temperature. After completion, the corresponding glycosyl donor was obtained by column chromatography purification.

[0079] The synthetic method of the present invention connects a phosphine oxide group to a glycosyl donor and utilizes the remote participation of the phosphine oxide group in the glycosidation reaction process to form a sterically hindered cyclic shielding structure similar to the participation of a neighboring group. This structure can cleverly shield the β face and promote the receptor to attack the α face, thereby obtaining excellent α selectivity.

[0080] Beneficial effects: Compared with the prior art, the present invention has the following advantages: (1) The present invention is the first to discover that commercially available diphenylphosphinoyl groups are used as remote directing groups (C-3 and C-5) to shield the β face of the sugar ring to achieve stereoselective glycosylation of the α face and efficiently synthesize α-2′-deoxyribonucleoside. This reaction is a brand-new idea and reaction mechanism that has not been reported in the literature. Among them, diphenylphosphinoyl groups (which can be directly synthesized using Ph2P(O)Cl) are widely used as precursors for synthesizing various chiral phosphine bidentate ligands (for asymmetric synthesis), but there is no literature report on their use in the present invention's C-3 and C-5 substituted protecting groups to prepare ribonucleosides. (2) In the present invention, different treatment methods are used for glycosyl receptors, purine receptors and pyrimidine receptors, among which pyrimidine receptors need to be silylated. In addition, the inventors have also found that there are special requirements for the selection of leaving groups (LG), and LG is o-alkynyl benzoate as the best. (3) The present invention has good stereoselectivity and regioselectivity, and the glycosylation of purine bases and pyrimidine bases as receptors is a single substitution product dominated by the α configuration. (4) The present invention can efficiently and stereoselectively synthesize α-2′-deoxyribonucleosides, the synthesis process is simple, the reaction conditions are mild, and the substrate application range is wide. (5) III-1 to III-25 synthesized by the present invention are brand-new compounds. (6) The present invention, for the first time, proposes that the target compound has good inhibitory activity against tumor cells such as SH-SY5Y and LN229 through anti-proliferation experiments. At the same time, the α-configuration and DPP group are crucial for maintaining the activity of the preferred compound III-17, which can be used as a lead compound for further development of anti-tumor drugs for central nervous system tumors and has good application prospects in the anti-tumor field. The present invention is of great help in exploring the potential value of α-configuration nucleosides, nucleotides and even nucleic acids in drug development. DETAILED DESCRIPTION

[0081] The present invention will be further described in detail below with reference to the examples, but the scope of protection of the present invention is not limited to these examples. The experimental methods in the following examples are conventional methods unless otherwise specified. The test materials used in the following examples were purchased from conventional biochemical reagent stores unless otherwise specified.

[0082] LG in the present invention refers to: a leaving group;

[0083] Bn in the present invention refers to: benzyl;

[0084] The Ac mentioned in the present invention refers to: acetyl;

[0085] The TBS described in the present invention refers to: tert-butyl dimethylsilyl ether;

[0086] Ph in the present invention refers to: a benzene ring;

[0087] The BSTFA of the present invention refers to: N, O-bis(trimethylsilyl)trifluoroacetamide;

[0088] The PPh3AuNTf2 described in the present invention refers to: triphenylphosphine bis(trifluoromethanesulfonimide) gold;

[0089] The DCM described in the present invention refers to: dichloromethane;

[0090] The DCE mentioned in the present invention refers to: dichloroethane;

[0091] The Et3N mentioned in the present invention refers to triethylamine, CAS#: 121-44-8;

[0092] The Me mentioned in the present invention refers to: methyl;

[0093] MeOH in the present invention refers to: methanol;

[0094] The MeONa described in the present invention refers to: sodium methoxide;

[0095] Bz in the present invention refers to: benzoyl;

[0096] The DPP of the present invention refers to: 2-diphenylphosphonyl;

[0097] The DPPA described in the present invention refers to: 2-diphenylphosphonoacetyl;

[0098] TLC in the present invention refers to: thin layer chromatography;

[0099] The compound of the present invention wherein all hydroxyl groups at position 5 are replaced by 2-diphenylphosphonoacetyl (DPPA) or 2-diphenylphosphono (DPP) and the hydroxyl group at position 3 is protected by a benzyl group is prepared according to the following route 1:

[0100]

[0101] For purine bases,

[0102] The glycosyl donor (1.2 eq, 20 mM) and the glycosyl acceptor (1.0 eq) were dissolved in dry dichloromethane. Under inert gas, molecular sieves (freshly activated) were added and stirred for 5 min. The reaction system was then cooled to -25°C and PPh3AuNTf2 (0.1 eq) was added. The mixture was gradually heated to room temperature with continued stirring. After TLC monitoring indicated the reaction was complete, the molecular sieves were filtered through an organic filter membrane, the mixture was concentrated under reduced pressure, and the corresponding product was isolated by silica gel column chromatography. Unless otherwise specified, the following glycosides were prepared according to the above route.

[0103] For pyrimidine bases,

[0104] The glycosyl donor (1.0 eq, 20 mM) and the glycosyl acceptor (1.5 eq) were dissolved in dry MeCN. Under inert gas, the temperature was raised to 50°C, and N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) (3.0 eq) was added. After the solution turned clear from turbidity, the solvent was evaporated, and dry dichloromethane (DCM) and freshly activated molecular sieves were added. Then, PPh3AuNTf2 (0.1 eq) was added at room temperature. After TLC monitoring indicated the reaction was complete, the molecular sieves were filtered through an organic filter membrane, the mixture was concentrated under reduced pressure, and the corresponding product was isolated by silica gel column chromatography. Unless otherwise specified, the following glycosides were prepared according to the above route.

[0105] The compound of the present invention wherein all 3 and 5 hydroxyl groups in formula III are substituted by 2-diphenylphosphonyl (DPP) is prepared according to the following route 2:

[0106]

[0107] For purine bases,

[0108] The glycosyl donor (1.2 eq, 20 mM) and the glycosyl acceptor (1.0 eq) were dissolved in dry dichloromethane. Under an inert atmosphere, molecular sieves (freshly activated) were added and stirred for 5 min. PPh3AuNTf2 (0.1 eq) was added at room temperature and stirring continued. After TLC monitoring indicated the reaction was complete, the molecular sieves were filtered through an organic filter membrane, the mixture was concentrated under reduced pressure, and the corresponding product was isolated by silica gel column chromatography. Unless otherwise specified, the following glycosides were prepared according to the above route.

[0109] For pyrimidine bases,

[0110] The glycosyl donor (1.0 eq, 20 mM) and glycosyl acceptor (1.5 eq) were dissolved in dry MeCN and the mixture was stirred under inert gas.

[0111] Under protective conditions, the temperature was raised to 50°C, and N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) (3.0 eq) was added. After the solution turned clear from turbidity, the solvent was evaporated, and dry dichloromethane (DCM) and freshly activated molecular sieves were added. Then, PPh3AuNTf2 (0.1 eq) was added at room temperature. After TLC monitoring indicated the reaction was complete, the molecular sieves were filtered through an organic filter membrane, the mixture was concentrated under reduced pressure, and the corresponding product was isolated by silica gel column chromatography. Unless otherwise specified, the following glycosides were prepared according to the above route.

[0112] Example 1 Compound III-1

[0113] According to route 1, the donor II-2 (40 mg, 0.061 mmol) and 2,6-dichloropurine receptor (9.6 mg, 0.051 mmol) were dissolved in dry dichloromethane (2.7 mL) and catalyzed by PPh3AuNTf2 (4.5 mg in 0.3 mL dry CH2Cl2, 0.0061 mmol). The crude product was separated by flash column chromatography to obtain a white syrup, which was the pure product of III-1 (27 mg, 83%, α / β>20:1): [α] D 20 =72.0 (c=1.0 in CHCl3); 1 H NMR (300MHz, CDCl3) δ8.54 (s, 1H), 7.84-7.72 (m, 4H), 7.61-7.42 (m, 6H), 7.34-7.27 (m, 3H), 7.21-7.11 (m, 2H), 6.44 (dd, J=7.7, 1 .5Hz, 1H), 4.55-4.40(m, 3H), 4.20-4.12(m, 2H), 4.07-3.99(m, 1H), 3.52(d, J=13.9Hz, 2H), 2.99-2.83(m, 1H), 2.60-2.47(m, 1H); 13 C NMR (100MHz, CDCl3) δ165.82, 165.76, 152.8, 152.6, 151.4, 145.1, 136.7 0, 132.67, 132.65, 132.6, 132.5, 132.2, 132.0, 131.1, 130.94, 130.92, 1 30.90, 130.82, 130.79, 129.1, 128.97, 128.95, 128.8, 128.7, 128.2, 127.7, 85.5, 84.2, 79.5, 72.1, 65.1, 39.3, 38.7, 38.1; HRMS(ESI)calcdforC 31 H 27 Cl2N4O5PNa[M+Na] + 659.0988, found 659.0982.

[0114] Example 2 Compound III-2

[0115] According to route 1, the donor II-2 (40 mg, 0.061 mmol) and 2-chloropurine receptor (7.9 mg, 0.051 mmol) were dissolved in dry dichloromethane (2.7 mL) and catalyzed by PPh3AuNTf2 (4.5 mg in 0.3 mL dry CH2Cl2, 0.0061 mmol). The crude product was separated by flash column chromatography to obtain a white syrup, which was the pure product of III-2 (16 mg, 53%, α only): [α] D 20 =-28.4 (c = 1.0 in CHCl3); 1 H NMR (300MHz, CDCl3) δ8.93 (s, 1H), 8.54 (s, 1H), 7.85-7.73 (m, 4H), 7.60-7.44 (m, 6H), 7.31 (m, 3H), 7.22-7.16 (m, 2H), 6.49 (dd, J=7. 7, 1.6Hz, 1H), 4.56-4.41 (m, 3H), 4.20-4.09 (m, 2H), 4.07-3.97 (m, 1H), 3.53 (d, J=14.0Hz, 2H), 2.98-2.82 (m, 1H), 2.61-2.46 (m, 1H); 13 C NMR (100MHz, CDCl3) δ165.93, 165.87, 154.4, 152.9, 150.0, 145.4, 136.9, 133.4, 132.8, 132.7, 132.61, 132.58, 132.2, 132.1, 131.2, 131.01, 13 1.03, 130.93, 130.91, 129.2, 129.0, 128.9, 128.8, 128.5, 128.3, 127.8, 127.7, 84.8, 84.1, 79.6, 72.1, 65.2, 39.4, 38.8, 38.2; HRMS(ESI)calcd for C 31 H 28 ClN4O5PNa[M+Na] + 625.1378, found 625.1377.

[0116] Example 3 Compound III-3

[0117] According to route 1, the donor II-2 (40 mg, 0.061 mmol) and 2-iodo-6-chloropurine receptor (14 mg, 0.051 mmol) were dissolved in dry dichloromethane (2.7 mL) and catalyzed by PPh3AuNTf2 (4.5 mg in 0.3 mL dry CH2Cl2, 0.0061 mmol). The crude product was separated by flash column chromatography to obtain a white syrup, which was the pure product of III-3 (31 mg, 84%, α only): [α] D 20 =17.0 (c = 1.0 in CHCl3); 1 H NMR (300MHz, CDCl3) δ8.48 (s, 1H), 7.86-7.72 (m, 4H), 7.62-7.46 (m, 6H), 7.36-7.28 (m, 3H), 7.20-7.14 (m, 2H), 6.42 (dd, J=7.6 , 1.4Hz, 1H), 4.55-4.38(m, 3H), 4.21-4.11(m, 2H), 4.04(m, 1H), 3.54(d, J=14.0Hz, 2H), 2.97-2.83(m, 1H), 2.57-2.46(m, 1H); 13 C NMR (100MHz, CDCl3) δ165.94, 165.88, 152.2, 150.3, 144.6, 136.8, 132.81, 132.79, 132.68, 132.65, 132.3, 132.1, 131.8, 131 .0, 130.9, 129.2, 129.1, 129.0, 128.8, 128.4, 127.8, 116.6, 85.5, 84.4, 79.6, 72.2, 65.2, 39.4, 38.8, 38.3; HRMS(ESI)calcd for C 31 H 27 ClIN4O5PNa[M+Na] + 751.0345, found 751.0346.

[0118] Example 4 Compound III-4

[0119] According to route 1, the donor II-2 (40 mg, 0.061 mmol) and 6-chloropurine receptor (7.9 mg, 0.051 mmol) were dissolved in dry dichloromethane (2.7 mL) and catalyzed by PPh3AuNTf2 (4.5 mg in 0.3 mL dry CH2Cl2, 0.0061 mmol). The crude product was separated by flash column chromatography to obtain a white syrup, which was the pure product of III-4 (25 mg, 82%, α only): [α]D 20 =15.7 (c = 1.0 in CHCl3); 1 H NMR (400MHz, CDCl3) δ8.74 (s, 1H), 8.56 (s, 1H), 7.84-7.74 (m, 4H), 7.60-7.45 (m, 6H), 7.35-7.28 (m, 3H), 7.23-7.13 (m, 2H), 6.54 (dd, J=7.6, 1.7H z, 1H), 4.53-4.50 (m, 1H), 4.49-4.42 (m, 2H), 4.22-4.13 (m, 2H), 4.09-4. 03(m, 1H), 3.53(d, J=14.0Hz, 2H), 2.96-2.82(m, 1H), 2.65-2.55(m, 1H); 13 C NMR (150MHz, CDCl3) δ165.9, 165.8, 152.0, 151.5, 150.9, 144.4, 136.9, 132.62, 132.60, 132.56, 132.5, 132.12, 132.10, 131.9, 131.43, 131.4 1, 131.0, 130.9, 129.08, 129.03, 128.96, 128.95, 128.9, 128.7, 128.3, 127.7, 85.3, 84.0, 79.6, 72.2, 65.1, 39.3, 38.9, 38.0; HRMS(ESI)calcd forC 31 H 28 ClN4O5PNa[M+Na] + 625.1378, found 625.1379.

[0120] Example 5 Compound III-5

[0121] According to route 1, the donor II-3 (40 mg, 0.060 mmol) and 6-chloropurine receptor (7.7 mg, 0.050 mmol) were dissolved in dry dichloromethane (2.7 mL) and catalyzed by PPh3AuNTf2 (4.4 mg in 0.3 mL dry CH2Cl2, 0.0060 mmol). The crude product was separated by flash column chromatography to obtain a white syrup, which was the pure product of III-5 (26 mg, 85%, α only): [α] D 20 =14.9 (c = 1.0 in CHCl3); 1H NMR (300MHz, CDCl3) δ8.72 (s, 1H), 8.58 (s, 1H), 7.80-7.68 (m, 4H), 7.58-7.44 (m, 6H), 7.35-7.26 (m, 3H), 7.21-7.1 3 (m, 2H), 6.57 (dd, J=7.0, 2.2Hz, 1H), 4.66-4.58 (m, 1H), 4.55-4.43 (m, 2H), 4.21-4.03 (m, 3H), 2.78-2.54 (m, 6H); 13 C NMR (100MHz, CDCl3) δ171.9, 171.7, 151.7, 151.1, 150.7, 144.0, 136.3, 132.3, 132.2, 132.00, 131.97, 131.6, 131.3, 131.2, 130.63, 130.62 , 130.54, 130.52, 128.8, 128.7, 128.64, 128.61, 128.5, 128.1, 127.5, 84.8, 83.7, 78.9, 71.9, 64.2, 37.9, 26.1, 25.0, 24.3; HRMS(ESI)calcd for C 32 H 30 ClN4O5PNa[M+Na] + 639.1535, found 639.1529.

[0122] Example 6 Compound III-6

[0123] According to route 1, the donor II-1 (40 mg, 0.066 mmol) and 6-chloropurine receptor (8.5 mg, 0.055 mmol) were dissolved in dry dichloromethane (3.0 mL) and catalyzed by PPh3AuNTf2 (4.9 mg in 0.3 mL dry CH2Cl2, 0.0066 mmol). The crude product was separated by flash column chromatography to obtain a white syrup, which was the pure product of III-6 (30 mg, 98%, α only): [α] D 20 =29.9 (c = 1.0 in CHCl3); 1H NMR (400MHz, CDCl3) δ8.72 (s, 1H), 8.60 (s, 1H), 7.86-7.76 (m, 4H), 7.60-7.52 (m, 2H), 7.52-7.43 (m, 4H), 7.29-7.24 (m, 3H), 7.16-7.12 (m, 2H), 6.61(dd, J=7.4, 1.6Hz, 1H), 4.72-4.66(m, 1H), 4.56-4.43(m, 3H), 4.17 -4.09(m, 1H), 4.08-3.99(m, 1H), 2.79-2.68(m, 1H), 2.67-2.60(m, 1H); 13 C NMR (100MHz, CDCl3) δ151.9, 151.4, 150.9, 144.3, 136.7, 132.70, 132.67, 131.8, 131.7, 131.6, 131.5, 131.44131.39, 131.1, 130.0, 129.8, 128.9, 128.8, 128.7, 128.5, 128.2, 127.7, 85.4, 85.32, 85.27, 79.5, 72.1, 64.32, 64.26, 38.3; HRMS(ESI)calcd for C 29 H 27 ClN4O4P[M+H] + 561.1453, found 561.1449.

[0124] Example 7 Compound III-7

[0125] According to route 1, the donor II-1 (40 mg, 0.066 mmol) and 2,6-dichloropurine receptor (10 mg, 0.055 mmol) were dissolved in dry dichloromethane (3.0 mL) and catalyzed by PPh3AuNTf2 (4.9 mg in 0.3 mL dry CH2Cl2, 0.0066 mmol). The crude product was separated by flash column chromatography to obtain a white syrup, which was the pure product of III-7 (32 mg, 97%, α only): [α] D 20 =20.0 (c = 1.0 in CHCl3); 1H NMR (300MHz, CDCl3) δ8.57 (s, 1H), 7.88-7.75 (m, 4H), 7.62-7.43 (m, 6H), 7.31-7.24 (m, 3H), 7.17-7.09 (m, 2H), 6.5 3(dd, J=7.2, 1.5Hz, 1H), 4.70(m, 1H), 4.57-4.40(m, 3H), 4.18-3.97(m, 2H), 2.77-2.64(m, 1H), 2.64-2.54(m, 1H); 13 C NMR (75MHz, CDCl3) δ152.8, 152.5, 151.5, 145.0, 136.6, 132.73, 132.70, 131.7, 131.6, 131.5, 131.4, 131.2, 130.9 , 129.7, 129.4, 128.9, 128.8, 128.7, 128.2, 127.7, 85.7, 85.6, 85.5, 79.5, 72.1, 64.3, 64.2, 38.5; HRMS(ESI)calcd forC 29 H 25 Cl2N4O4PNa[M+Na] + 617.0876, found 617.0883.

[0126] Example 8 Compound III-8

[0127] According to route 1, the donor II-1 (40 mg, 0.066 mmol) and 2-chloropurine receptor (8.5 mg, 0.055 mmol) were dissolved in dry dichloromethane (3.0 mL) and catalyzed by PPh3AuNTf2 (4.9 mg in 0.3 mL dry CH2Cl2, 0.0066 mmol). The crude product was separated by flash column chromatography to obtain a white syrup, which was the pure product of III-8 (30 mg, 96%, α only): [α] D 20 =15.1 (c=1.0 in CHCl3); 1 H NMR (300MHz, CDCl3) δ8.95 (s, 1H), 8.58 (s, 1H), 7.89-7.76 (m, 4H), 7.62-7.42 (m, 6H), 7.34-7.27 (m, 3H), 7.21-7.11 (m, 2H), 6.60(dd, J=7.4, 1.6Hz, 1H), 4.75-4.66(m, 1H), 4.59-4.43(m, 3H), 4.19-3.97(m, 2H), 2.81-2.65(m, 1H), 2.64-2.53(m, 1H);13 C NMR (100MHz, CDCl3) δ154.4, 152.8, 150.1, 145.3, 136.8, 133.5, 132.78, 132.81, 131.9, 131.8, 131.6, 131.53, 131.49, 131 .2, 130.1, 129.8, 129.0, 128.9, 128.8, 128.3, 127.9, 85.6, 85.5, 84.9, 79.6, 72.2, 64.44, 64.38, 38.5; HRMS(ESI)calcdfor C 29 H 27 ClN4O4P[M+H] + 561.1453, found 561.1449.

[0128] Example 9 Compound III-9

[0129] According to route 1, the donor II-1 (40 mg, 0.066 mmol) and 2-amino-6-chloropurine receptor (17 mg, 0.099 mmol) were dissolved in dry dichloromethane (3.0 mL) and catalyzed by PPh3AuNTf2 (4.9 mg in 0.3 mL dry CH2Cl2, 0.0066 mmol). The crude product was separated by flash column chromatography to obtain a white syrup, which was the pure product of III-9 (27 mg, 71%, α only): [α] D 20 =46.0 (c = 1.0 in CHCl3); 1 H NMR (300MHz, CDCl3) δ8.26 (s, 1H), 7.87-7.74 (m, 4H), 7.58-7.43 (m, 6H), 7.33-7.26 (m, 3H), 7.24-7.14 (m, 2H), 6.39 (dd, J=7.6, 1.9Hz , 1H), 5.32(s, 2H), 4.68-4.58(m, 1H), 4.58-4.47(m, 2H), 4.46-4.40(m, 1H), 4.19-3.92(m, 2H), 2.75-2.62(m, 1H), 2.60-2.50(m, 1H); 13C NMR (75MHz, CDCl3) δ159.1, 153.5, 151.2, 141.3, 136.8, 132.64, 132.61, 131.8, 131.6, 131.5, 131.4, 129.8, 129 .6, 128.9, 128.71, 128.67, 128.1, 127.7, 125.3, 84.8, 84.7, 84.3, 79.5, 72.1, 64.4, 64.3, 38.0; HRMS(ESI)calcd for C 29 H 27 ClN5O4PNa[M+Na] + 598.1381, found 598.1387.

[0130] Example 10 Compound III-10

[0131] According to route 1, the donor I-2 (40 mg, 0.061 mmol) and the uracil acceptor (10 mg, 0.092 mmol) were dissolved in dry MeCN. Under inert gas protection, the temperature was raised to 50°C, and BSTFA (73 μL, 0.28 mmol) was added. After the solution turned from turbid to clear, the solvent was dried and added to dry DCM (1.0 mL). The reaction was catalyzed by PPh3AuNTf2 (4.5 mg in 2.0 mL dry CH2Cl2, 0.0061 mmol) to obtain the crude product. The white syrup obtained after flash column chromatography was the pure product of III-10 (24 mg, 70%, α only): [α] D 20 =3.4 (c = 1.0 in CHCl3); 1 H NMR (400MHz, CDCl3) δ9.53 (s, 1H), 7.80v7.71 (m, 4H), 7.63-7.58 (m, 1H), 7.57-7.43 (m, 6H), 7.38-7.27 (m, 3H), 7.25-7.18 (m, 2H), 6.20 (dd, J =7.6, 2.2Hz, 1H), 5.62 (dd, J = 8.1, 2.0Hz, 1H), 4.49-4.36 (m, 3H), 4.07 -3.87(m, 3H), 3.66-3.46(m, 2H), 2.67-2.51(m, 1H), 2.19-2.11(m, 1H); 13C NMR (100MHz, CDCl3) δ166.03, 165.97, 163.5, 150.8, 140.7, 136.9, 132.6, 131.7, 131.0, 130.9, 130.7, 129.0, 128 .9, 128.81, 128.83, 128.6, 128.2, 127.8, 102.0, 86.6, 83.8, 78.9, 71.5, 65.1, 38.9, 38.3, 37.7; HRMS(ESI)calcd for C 30 H 29 N2O7PNa[M+Na] + 583.1605, found 583.1615.

[0132] Example 11 Compound III-11

[0133] According to route 1, the donor I-2 (40 mg, 0.061 mmol) and the 5-methyluracil acceptor (12 mg, 0.092 mmol) were dissolved in dry MeCN. Under inert gas protection, the temperature was raised to 50°C, and BSTFA (73 μL, 0.28 mmol) was added. After the solution turned from turbid to clear, the solvent was dried and added to dry DCM (1.0 mL). The reaction was catalyzed by PPh3AuNTf2 (4.5 mg in 2.0 mL dry CH2Cl2, 0.0061 mmol) to obtain the crude product. The white syrup obtained after flash column chromatography was the pure product of III-11 (23 mg, 65%, α only): [α] D 20 =2.6 (c = 1.0 in CHCl3); 1 H NMR (400MHz, CDCl3) δ 8.52-8.40 (m, 1H), 7.83-7.74 (m, 4H), 7.59-7.45 (m, 7H), 7.37-7.30 (m, 3H), 7.26-7.22 (m, 2H), 6.23 (dd, J=7.8, 2.4Hz, 1H ), 4.53-4.48(m, 1H), 4.44(m, 2H), 4.05-3.98(m, 3H), 3.53(dd, J=14.2, 1.0Hz, 2H), 2.69-2.55 (m, 1H), 2.19-2.10 (m, 1H), 1.76 (d, J=1.2Hz, 3H); 13C NMR (100MHz, CDCl3) δ165.83, 165.77, 163.6, 150.3, 137.0, 136.5, 132.5 2, 132.50, 132.47, 132.4, 132.3, 132.1, 131.2, 131.1, 131.03, 130.97, 1 30.93, 130.87, 129.0, 128.9, 128.84, 128.76, 128.6, 128.2, 127.7, 110. 3, 86.2, 83.6, 79.2, 71.6, 65.1, 39.3, 38.7, 37.8, 12.4; HRMS(ESI)calcd for C 31 H 31 N2O7PNa[M+Na] + 597.1761, found 597.1764.

[0134] Example 12 Compound III-12

[0135] According to route 1, the donor I-2 (40 mg, 0.061 mmol) and the 5-fluorouracil acceptor (12 mg, 0.092 mmol) were dissolved in dry MeCN. Under inert gas protection, the temperature was raised to 50°C, and BSTFA (73 μL, 0.28 mmol) was added. After the solution turned from turbid to clear, the solvent was dried and added to dry DCM (1.0 mL). The reaction was catalyzed by PPh3AuNTf2 (4.5 mg in 2.0 mL dry CH2Cl2, 0.0061 mmol) to obtain the white syrup obtained after separation of the crude product by flash column chromatography, which was the pure product of III-12 (24 mg, 69%, α only): [α] D 20 =-4.3 (c = 1.0 in CHCl3); 1 H NMR (300MHz, CDCl3) δ7.84-7.73 (m, 5H), 7.59-7.44 (m, 6H), 7.38-7.29 (m, 3H), 7.25-7.20 (m, 2H), 6.19 (dt, J=7 .6, 1.8Hz, 1H), 4.51-4.40(m, 3H), 4.05-3.91(m, 3H), 3.65-3.48(m, 2H), 2.72-2.57(m, 1H), 2.21-2.10(m, 1H); 13C NMR (100MHz, CDCl3) δ165.93, 165.87, 157.3, 157.0, 149.2, 139.1, 136.7, 132.6, 131.8, 131.7, 131.01, 130.98, 130.91, 130.88, 130.8, 1 30.7, 129.0, 128.93, 128.85, 128.8, 128.7, 128.2, 127.7, 125.2, 124.9, 87.0, 83.9, 78.9, 71.6, 65.2, 39.0, 38.4, 37.8; HRMS(ESI)calcd for C 30 H 28 FN2O7PNa[M+Na] + 601.1510, found 601.1517.

[0136] Example 13 Compound III-13

[0137] According to route 1, the donor I-1 (40 mg, 0.066 mmol) and the uracil acceptor (11 mg, 0.099 mmol) were dissolved in dry MeCN. Under inert gas protection, the temperature was raised to 50°C, and BSTFA (79 μL, 0.30 mmol) was added. After the solution turned from turbid to clear, the solvent was dried and added to dry DCM (1.0 mL). The reaction was catalyzed by PPh3AuNTf2 (4.9 mg in 2.3 mL dry CH2Cl2, 0.0066 mmol) to obtain the crude product. The white syrup obtained after flash column chromatography was the pure product of III-13 (30 mg, 89%, α only): [α] D 20 =3.4 (c = 1.0 in CHCl3); 1 H NMR (400MHz, CDCl3) δ9.40 (s, 1H), 7.83-7.75 (m, 4H), 7.69-7.63 (m, 1H), 7.58-7 .51(m, 2H), 7.51-7.43(m, 4H), 7.35-7.25(m, 3H), 7.23-7.16(m, 2H), 6.30(dd, J =7.6, 2.0Hz, 1H), 5.64 (dd, J = 8.2, 1.8Hz, 1H), 4.68-4.62 (m, 1H), 4.51-4.43 (m, 2H), 4.32-4.26(m, 1H), 4.10-3.93(m, 2H), 2.62-2.51(m, 1H), 2.27-2.18(m, 1H); 13C NMR (75MHz, CDCl3) δ163.7, 150.7, 140.8, 136.8, 132.73, 132.69, 131.7, 131.6, 131.5, 131.41, 131.38, 131.2, 129. 5, 129.4, 128.9, 128.8, 128.6, 128.2, 127.8, 101.9, 86.9, 85.4, 85.3, 79.0, 71.5, 64.5, 64.4, 38.0; HRMS(ESI)calcd forC 28 H 27 N2O6PNa[M+Na] + 541.1499, found 541.1501.

[0138] Example 14 Compound III-14

[0139] According to route 1, the donor I-1 (40 mg, 0.066 mmol) and the 5-methyluracil acceptor (12 mg, 0.099 mmol) were dissolved in dry MeCN. Under inert gas protection, the temperature was raised to 50°C, and BSTFA (79 μL, 0.30 mmol) was added. After the solution turned from turbid to clear, the solvent was dried and added to dry DCM (1.0 mL). The reaction was catalyzed by PPh3AuNTf2 (4.9 mg in 2.3 mL dry CH2Cl2, 0.0066 mmol) to obtain the crude product. The white syrup obtained after flash column chromatography was the pure product of III-14 (30 mg, 86%, α only): [α] D 20 =-12.6 (c = 1.0 in CHCl3); 1 H NMR (400MHz, CDCl3) δ9.21 (m, 1H), 7.84-7.75 (m, 4H), 7.58-7.43 (m, 7H), 7.34-7.27 (m, 3H), 7.25-7.20 (m, 2H), 6.37 (dd, J=7.8, 2.3Hz, 1H) ,4.71-4.62(m,1H),4.53-4.43(m,2H),4.34-4.28(m,1H),4.12-3.93(m,2H),2.67-2.54(m,1H),2.25-2.17(m,1H),1.75(d,J=1.2Hz,3H); 13C NMR (100MHz, CDCl3) δ164.0, 150.8, 136.9, 136.6, 132.71, 132.68, 131.7, 131.6, 131.5, 131.4, 131.2, 131.0, 129.8, 1 29.6, 128.9, 128.8, 128.6, 128.2, 127.7, 110.6, 86.3, 85.0, 84.9, 79.3, 71.6, 64.7, 64.6, 37.9, 12.4; HRMS(ESI)calcd forC 29 H 29 N2O6PNa[M+Na] + 555.1655, found 555.1661.

[0140] Example 15 Compound III-15

[0141] According to route 1, the donor I-1 (40 mg, 0.066 mmol) and the 5-fluorouracil acceptor (13 mg, 0.099 mmol) were dissolved in dry MeCN. Under inert gas protection, the temperature was raised to 50°C, and BSTFA (79 μL, 0.30 mmol) was added. After the solution turned from turbid to clear, the solvent was dried and added to dry DCM (1.0 mL). The reaction was catalyzed by PPh3AuNTf2 (4.9 mg in 2.3 mL dry CH2Cl2, 0.0066 mmol) to obtain the crude product. The white syrup obtained after flash column chromatography was the pure product of III-15 (31 mg, 88%, α only): [α] D 20 =4.0 (c = 1.0 in CHCl3); 1 H NMR (400MHz, CDCl3) δ9.77 (d, J=4.7Hz, 1H), 7.86-7.82 (m, 1H), 7.81-7.73 ( m, 4H), 7.58-7.51 (m, 2H), 7.50-7.43 (m, 4H), 7.34-7.27 (m, 3H), 7.25-7.19 (m, 2H), 6.33 (dt, J=7.7, 1.9Hz, 1H), 4.69-4.62 (m, 1H), 4.55-4.45 (m, 2H), 4.31-4.25(m, 1H), 4.07-3.94(m, 2H), 2.66-2.54(m, 1H), 2.24-2.17(m, 1H); 13C NMR (75MHz, CDCl3) δ157.4, 149.4, 136.7, 132.82, 132.79, 131.7, 131.6, 131.53, 131.45, 131.04, 130.98, 129.2, 129.0, 128.8, 128.7, 128.2, 127.8, 125.5, 125.0, 87.0, 85.3, 85.2, 78.9, 71.7, 64.7, 64.6, 37.8; HRMS(ESI)calcd for C 28 H 26 FN2O6PNa[M+Na] + 559.1405, found 559.1412.

[0142] Example 16 Compound III-16

[0143] According to route 1, the donor I-1 (40 mg, 0.066 mmol) and the 5-trifluoromethyluracil acceptor (18 mg, 0.099 mmol) were dissolved in dry MeCN. Under inert gas protection, the temperature was raised to 50°C, and BSTFA (79 μL, 0.30 mmol) was added. After the solution turned from turbid to clear, the solvent was dried and added to dry DCM (1.0 mL). The reaction was catalyzed by PPh3AuNTf2 (4.9 mg in 2.3 mL dry CH2Cl2, 0.0066 mmol) to obtain the crude product. The white syrup obtained after flash column chromatography was the pure product of III-16 (36 mg, 93%, α only): [α] D 20 =-17.3 (c = 1.0 in CHCl3); 1 HNMR (400MHz, CDCl3) δ9.72 (s, 1H), 8.10 (s, 1H), 7.85-7.74 (m, 4H), 7.59-7.51 (m, 2H), 7.51-7.44 (m, 4H), 7.31-7.25 (m, 3H), 7.21-7.13 ( m, 2H), 6.24 (dd, J=7.3, 1.3Hz, 1H), 4.76-4.65 (m, 1H), 4.51-4.41 (m, 2H), 4.31 (m, 1H), 4.13-3.92 (m, 2H), 2.64-2.52 (m, 1H), 2.27 (m, 1H); 13C NMR (100MHz, CDCl3) δ158.9, 149.7, 141.7, 141.6, 136.5, 132.82, 132.79, 131.7, 131.6, 131.5, 131.4, 130.9, 130.8, 129.6, 129.4, 129.0 , 128.8, 128.6, 128.2, 127.8, 123.3, 120.6, 105.0, 104.7, 104.3, 104.0, 87.9, 86.0, 85.9, 79.0, 71.9, 64.4, 64.3, 38.4; HRMS(ESI)calcd for C 29 H 26 F3N2O6PNa[M+Na] + 609.1373, found 609.1372.

[0144] Example 17 Compound III-17

[0145] According to route 1, the donor I-4 (80 mg, 0.11 mmol) and 2,6-dichloropurine receptor (17 mg, 0.093 mmol) were dissolved in dry DCE (5.0 mL) and catalyzed by PPh3AuNTf2 (8.2 mg in 0.30 mL dry DCE, 0.011 mmol). The crude product was separated by flash column chromatography to obtain a white syrup, which was the pure product of III-17 (63 mg, 96%, α / β>20:1): [α] D 20 =v8.5 (c=1.0 in CHCl3); 1 H NMR (300MHz, CDCl3) δ8.37 (s, 1H), 7.82-7.70 (m, 4H), 7.60-7.30 (m, 16H), 6.43 (dd, J=6.9, 1.4Hz, 1 H), 5.30v5.18(m, 1H), 4.94-4.85(m, 1H), 4.13-4.03(m, 2H), 3.02-2.92(m, 1H), 2.82-2.69(m, 1H); 13C NMR (100MHz, CDCl3) δ152.8, 152.1, 151.6, 144.0, 132.89, 132.86, 132.8, 132.72 ,132.70,132.68,131.7,131.64,131.62,131.60,131.5,131.3,131.2,131.1,131 .0, 130.8, 130.7, 129.6, 129.5, 129.4, 128.94, 128.90, 128.81, 128.77, 128.7, 86 .83, 86.78, 86.76, 86.7, 75.22, 75.16, 63.7, 63.6, 39.92, 39.89; HRMS(ESI)calcd for C 34 H 28 Cl2N4O5P2Na[M+Na] + 727.0804, found727.0802.

[0146] Example 18 Compound III-18

[0147] According to route 1, the donor I-4 (80 mg, 0.11 mmol) and 2-amino-6-chloropurine receptor (28 mg, 0.17 mmol) were dissolved in dry CH3CN (2.0 mL) and catalyzed by PPh3AuNTf2 (8.2 mg in 3.6 mL dry DCE, 0.011 mmol). The crude product was separated by flash column chromatography to obtain a white syrup, which was the pure product of III-18 (62 mg, 82%, α only): [α] D 20 =3.2 (c = 1.0 in CHCl3); 1 H NMR (300MHz, CDCl3) δ8.04 (s, 1H), 7.82-7.69 (m, 4H), 7.67-7.49 (m, 7H), 7.47-7.31 (m, 9H), 6.28 (dd, J=7 .1, 1.8Hz, 1H), 5.37-5.17(m, 3H), 4.84-4.69(m, 1H), 4.15-3.93(m, 2H), 2.97-2.83(m, 1H), 2.69(m, 1H); 13C NMR (100MHz, CDCl3) δ159.0, 153.0, 151.3, 140.2, 132.9, 132.83, 132.80, 132.8, 132. 78, 132.68, 132.67, 131.66, 131.64, 131.61, 131.5, 131.34, 131.28, 131.23, 131.17, 1 30.97, 130.96, 130.8, 129.6, 129.5, 129.0, 128.9, 128.84, 128.83, 128.73, 0028.71, 1 25.7, 86.0, 85.91, 85.85, 85.6, 75.04, 74.99, 63.8, 63.7, 39.3, 39.2; HRMS(ESI)calcd for C 34 H 30 ClN5O5P2Na[M+Na] + 708.1303, found 708.1298.

[0148] Example 19 Compound III-19

[0149] According to route 1, the donor I-4 (80 mg, 0.11 mmol) and 2v chloro-6-aminopurine receptor (28 mg, 0.17 mmol) were dissolved in dry CH3CN (2.0 mL) and catalyzed by PPh3AuNTf2 (8.2 mg in 3.6 mL dry DCE, 0.011 mmol). The crude product was separated by flash column chromatography to obtain a white syrup, which was the pure product of III-19 (68 mg, 90%, α / β = 15:1): [α] D 20 =3.6 (c = 1.0 in CHCl3); 1 H NMR (300MHz, CDCl3) δ8.06 (s, 1H), 7.84-7.70 (m, 4H), 7.60-7.34 (m, 16H), 6.38 (dd, J=6.9, 1.7H z, 1H), 6.33 (s, 2H), 5.33-5.14 (m, 1H), 4.96-4.84 (m, 1H), 4.25-3.99 (m, 2H), 2.99-2.63 (m, 2H); 13C NMR (100MHz, CDCl3) δ156.1, 154.0, 150.3, 139.0, 132.8, 132.75, 132.74, 132.73, 132.70, 1 32.63, 132.61, 131.8, 131.7, 131.62, 131.56, 131.52, 131.45, 131.35, 131.27, 131.2, 131.1 1, 131.09, 131.0, 130.9, 129.74, 129.72, 129.64, 129.56, 128.9, 128.8, 128.74, 128.71, 118 .8, 86.40, 86.35, 86.34, 86.33, 86.2, 75.3, 75.2, 63.64, 63.59, 39.9, 39.8; HRMS(ESI)calcd forC 34 H 30 ClN5O5P2Na[M+Na] + 708.1303, found 708.1304.

[0150] Example 20 Compound III-20

[0151] According to route 1, donor I-4 (80 mg, 0.11 mmol) and 2-Boc amino-6v chloropurine receptor (25 mg, 0.093 mmol) were dissolved in dry DCE (5.0 mL) and reacted with PPh3AuNTf2 (8.2 mg in 0.3 mL dry DCE, 0.011 mm o l) The crude product was separated by rapid column chromatography to obtain a white syrup, which was the pure product of III-20 (63 mg, 86%, α only): [α] D 20 =-4.6 (c = 1.0 in CHCl3); 1 H NMR (400MHz, CDCl3) δ8.24 (s, 1H), 7.83-7.71 (m, 4H), 7.60v7.41 (m, 13H), 7.40-7.31 (m, 4H), 6.44 (dd, J=7.0, 1.7H z, 1H), 5.25-5.16 (m, 1H), 4.91-4.82 (m, 1H), 4.13-3.99 (m, 2H), 3.18-3.07 (m, 1H), 2.80-2.67 (m, 1H), 1.53 (s, 9H); 13C NMR (100MHz, CDCl3) δ152.2, 152.1, 151.1, 150.1, 142.4, 132.8, 132.74, 132.71, 1 32.61, 132.59, 132.56, 131.8, 131.7, 131.6, 131.5, 131.4, 131.3, 131.14, 131.07 ,130.9,129.8,129.7,129.5,128.89,128.85,128.81,128.76,128.72,128.68,12 8.2, 86.23, 86.18, 86.1, 81.7, 75.2, 75.1, 63.6, 63.5, 39.5, 28.2; HRMS(ESI)calcd forC 39 H 38 ClN5O7P2Na[M+Na] + 808.1827, found 808.1842.

[0152] Example 21 Compound III-21

[0153] According to route 1, the donor I-4 (80 mg, 0.11 mmol) and 2-fluoro-6-chloropurine receptor (16 mg, 0.093 mmol) were dissolved in dry DCE (5.0 mL) and catalyzed by PPh3AuNTf2 (8.2 mg in 0.3 mL dry DCE, 0.011 mmol). The crude product was separated by flash column chromatography to obtain a white syrup, which was the pure product of III-21 (57 mg, 89%, α only): [α] D 20 =4.3 (c = 1.0 in CHCl3); 1 H NMR (300MHz, CDCl3) δ8.36 (s, 1H), 7.84-7.71 (m, 4H), 7.59-7.44 (m, 12H), 7.43-7.30 (m, 4H), 6.39 (dd, J=6.9 , 1.5Hz, 1H), 5.31-5.19(m, 1H), 4.94-4.84(m, 1H), 4.16-4.01(m, 2H), 3.02-2.88(m, 1H), 2.83-2.65(m, 1H); 13C NMR (100MHz, CDCl3) δ158.1, 155.9, 152.7, 152.6, 152.52, 152.46, 144.0, 143.9, 132.9, 132.85 , 132.83, 132.80, 132.70, 132.67, 132.6, 131.7, 131.62, 131.60, 131.5, 131.22, 131.21, 131.12 , 131.10, 131.07, 130.90, 130.85, 130.8, 129.7, 129.54, 129.46, 128.94, 128.88, 128.8, 128.7 5, 128.67, 86.8, 86.72, 86.69, 86.6, 75.21, 75.16, 63.64, 63.58, 39.80, 39.77; HRMS(ESI)calcd for C 34 H 28 ClFN4O5P2Na[M+Na] + 711.1100, found 711.1095.

[0154] Example 22 Compound III-22

[0155] According to route 1, the donor I-4 (80 mg, 0.11 mmol) and 6-Boc aminopurine receptor (31 mg, 0.093 mmol) were dissolved in dry DCE (5.0 mL) and catalyzed by PPh3AuNTf2 (8.2 mg in 0.3 mL dry DCE, 0.011 mmol). The crude product was separated by flash column chromatography to obtain a white syrup, which was the pure product of III-22 (61 mg, 77%, α only): [α] D 20 =9.5 (c = 1.0 in CHCl3); 1 H NMR (400MHz, CDCl3) δ8.85 (s, 1H), 8.39 (s, 1H), 7.84-7.76 (m, 4H), 7.69-7.62 (m, 2H), 7.60-7.53 (m, 4H), 7.52-7.35 (m, 10 H), 6.53 (dd, J=6.6, 2.7Hz, 1H), 5.33-5.22 (m, 1H), 4.95-4.84 (m, 1H), 4.16-4.06 (m, 2H), 2.92-2.76 (m, 2H), 1.46 (s, 18H); 13C NMR (100MHz, CDCl3) δ152.6, 152.1, 150.5, 150.4, 142.9, 132.8, 132.7, 132.6, 131.8, 1 31.6, 131.5, 131.43, 131.36, 131.32, 131.26, 131.15, 131.12, 131.0, 130.9, 129.78, 1 29.76, 129.7, 129.6, 129.3, 129.0, 128.93, 128.85, 128.84, 128.80, 128.7, 86.21, 86. 16, 86.14, 86.09, 85.7, 83.9, 75.1, 75.0, 63.7, 63.6, 39.7, 39.6, 27.8; HRMS(ESI)calcd for C 44 H 47 N5O9P2Na[M+Na] + 874.2741, found 874.2758

[0156] Example 23 Compound III-23

[0157] According to route 1, the donor I-4 (80 mg, 0.11 mmol) and the uracil acceptor (19 mg, 0.17 mmol) were dissolved in dry MeCN. Under inert gas protection, the temperature was raised to 50°C, and BSTFA (135 μL, 0.51 mmol) was added. After the solution turned from turbid to clear, the solvent was dried and added to dry CH3CN (2.0 mL). The reaction was catalyzed by PPh3AuNTf2 (8.2 mg in 3.3 mL dry CH2Cl2, 0.011 mmol) to obtain the white syrup obtained after separation of the crude product by flash column chromatography, which was the pure product of III-23 (63 mg, 91%, α / β>20:1): [α] D 20 =-7.8 (c = 1.0 in CHCl3); 1 H NMR (400MHz, CDCl3) δ9.21 (m, 1H), 7.80-7.65 (m, 8H), 7.57-7.52 (m, 4H), 7.51-7.37 (m, 9H), 6.17 (dd, J=7.0, 1.7Hz, 1H), 5.50 (d, J=8.2Hz, 1H), 5.09-5.02(m, 1H), 4.97-4.91(m, 1H), 4.09-4.02(m, 1H), 4.01-3.93(m, 1H), 2.70-2.59(m, 1H), 2.50-2.42(m, 1H); 13C NMR (100MHz, CDCl3) δ163.3, 150.2, 139.7, 132.93, 132.90, 132.86, 132.7, 131. 7, 131.63, 131.58, 131.55, 131.48, 131.45, 131.3, 131.2, 131.03, 131.01, 130.9 ,130.8,129.7,129.6,129.52,129.49,129.0,128.89,128.85,128.8,101.5,87 .7, 87.00, 86.97, 86.93, 86.90, 75.5, 75.4, 63.61, 63.56, 40.3; HRMS(ESI)calcd for C 33 H 30 N2O7P2Na[M+Na] + 651.1421, found 651.1411.

[0158] Example 24 Compound III-24

[0159] According to route 1, the donor I-4 (80 mg, 0.11 mmol) and the 5-methyluracil acceptor (21 mg, 0.17 mmol) were dissolved in dry MeCN. Under inert gas protection, the temperature was raised to 50°C, and BSTFA (135 μL, 0.51 mmol) was added. After the solution turned from turbid to clear, the solvent was dried and added to dry CH3CN (2.0 mL). The reaction was catalyzed by PPh3AuNTf2 (8.2 mg in 3.3 mL dry CH2Cl2, 0.011 mmol) to obtain the white syrup obtained after separation of the crude product by flash column chromatography, which was the pure product of III-24 (66 mg, 93%, α / β>20:1): [α] D 20 =5.9 (c = 1.0 in CHCl3); 1 H NMR (400MHz, CDCl3) δ9.21 (s, 1H), 7.79-7.66 (m, 8H), 7.56-7.38 (m, 12H), 7.37-7.35 (m, 1H), 6.23 (dd, J=7.2, 1.9Hz, 1H), 5.07- 5.00(m, 1H), 5.00-4.94(m, 1H), 4.08-4.02(m, 1H), 3.98-3.90(m, 1H), 2.70-2.59(m, 1H), 2.48-2.36(m, 1H), 1.64-1.57(m, 3H); 13C NMR (100MHz, CDCl3) δ163.9, 150.3, 135.6, 132.88, 132.91, 132.84, 132.81, 132.67, 132 .65, 132.6, 131.7, 131.65, 131.58, 131.57, 131.48, 131.46, 131.3, 131.2, 131.05, 131.0 3, 130.8, 129.68, 129.66, 129.5, 129.0, 128.93, 128.88, 128.80, 128.75, 110.2, 87.2, 86 .8, 86.71, 86.68, 86.6, 75.64, 75.58, 63.64, 63.58, 40.14, 40.09, 12.3; HRMS(ESI)calcd for C 34 H 32 N2O7P2Na[M+Na] + 665.1577, found 665.1565.

[0160] Example 25 Compound III-25

[0161] According to route 1, the donor I-4 (80 mg, 0.11 mmol) and the 5-fluoromethyluracil acceptor (22 mg, 0.17 mmol) were dissolved in dry MeCN. Under inert gas protection, the temperature was raised to 50°C, and BSTFA (135 μL, 0.51 mmol) was added. After the solution turned from turbid to clear, the solvent was dried and added to dry CH3CN (2.0 mL). The reaction was catalyzed by PPh3AuNTf2 (8.2 mg in 3.3 mL dry CH2Cl2, 0.011 mmol) to obtain the crude product. The white syrup obtained after separation by flash column chromatography was the pure product of III-26 (69 mg, 97%, α only): [α] D 20 =-12.0 (c = 1.0 in CHCl3); 1 H NMR (400MHz, CDCl3) δ9.80-9.61 (m, 1H), 7.79-7.66 (m, 8H), 7.63 (d, J=6.2Hz, 1H), 7.57-7.38 (m, 12H), 6.20 (dt, J=7.1, 1.6 Hz, 1H), 5.11-5.03 (m, 1H), 4.97-4.91 (m, 1H), 4.10-3.99 (m, 1H), 3.99-3.91 (m, 1H), 2.74-2.62 (m, 1H), 2.51-2.40 (m, 1H); 13C NMR (100MHz, CDCl3) δ157.1, 156.8, 148.7, 141.4, 139.0, 132.99, 132.96, 132.9, 132. 7, 131.7, 131.62, 131.59, 131.5, 131.4, 131.34, 131.32, 131.2, 130.9, 130.78, 130.76 , 130.7, 129.5, 129.42, 129.39, 129.37, 129.0, 128.90, 128.87, 128.8, 124.3, 123.9, 8 7.6, 87.05, 87.00, 86.98, 86.9, 75.5, 75.4, 63.61, 63.56, 40.2, 40.1; HRMS(ESI)calcd for C 33 H 29 FN2O7P2Na[M+Na] + 669.1326, found 669.1318.

[0162] Example 26 Compound III-26

[0163] According to route 1, donor I-4 (80 mg, 0.11 mmol) and 5-trifluoromethyluracil acceptor (30 mg, 0.17 mm o l) was dissolved in dry MeCN and heated to 50°C under inert gas. BSTFA (135 μL, 0.51 mmol) was added. After the solution turned clear from turbidity, the solvent was dried and added to dry CH3CN (2.0 mL). The reaction was catalyzed by PPh3AuNTf2 (8.2 mg in 3.3 mL dry CH2Cl2, 0.011 mmol). The crude product was separated by flash column chromatography to obtain a white syrup, which was pure III-26 (74 mg, 96%, α only): [α] D 20 =-7.1 (c = 1.0 in CHCl3); 1 H NMR (300MHz, CDCl3) δ7.96 (d, J=1.2Hz, 1H), 7.81-7.59 (m, 8H), 7.59-7.35 (m, 12H), 6.14 (dd, J=6.9, 1.4 Hz, 1H), 5.15-5.04 (m, 1H), 4.96-4.87 (m, 1H), 4.10-3.90 (m, 2H), 2.75-2.61 (m, 1H), 2.55-2.44 (m, 1H); 13C NMR (100MHz, CDCl3) δ158.6, 149.2, 140.25, 140.19, 133.0, 132.9, 132.8, 132.75, 132.72, 131.7, 131.61, 131.59, 131.5, 131.3, 131.2, 130.78, 130.76, 130.7, 130. 5, 129.42, 129.40, 129.3, 129.2, 129.0, 128.92, 128.87, 128.8, 104.6, 104.2, 88. 4, 87.52, 87.47, 87.46, 87.4, 75.3, 75.2, 63.6, 63.5, 40.4, 40.3; HRMS(ESI)calcd for C 34 H 29 F3N2O7P2Na[M+Na] + 719.1294, found 719.1297.

[0164] Example 27 Compound III-27

[0165] According to route 1, the donor I-4 (80 mg, 0.11 mmol) and the acceptor II-13 (36 mg, 0.17 mmol) were dissolved in dry MeCN. Under inert gas protection, the temperature was raised to 50 ° C. BSTFA (135 μL, 0.51 mmol) was added. After the solution turned from turbid to clear, the solvent was dried and added to dry CH3CN (2.0 mL). The reaction was catalyzed by PPh3AuNTf2 (8.2 mg in 3.3 mL dry DCE, 0.011 mmol). The crude product was separated by flash column chromatography to obtain a white syrup, which was the pure product of III-27 (41 mg, 51%, α / β>20:1): [α] D 20 =-19.5 (c = 1.0 in CHCl3); 1 H NMR (300MHz, CDCl3) δ8.90 (s, 1H), 8.03-7.91 (m, 3H), 7.85-7.73 (m, 4H), 7.68-7.37 (m, 20H), 6.23 ( dd, J=6.0, 1.9Hz, 1H), 5.12-5.04(m, 2H), 4.20-4.09(m, 1H), 4.09-3.99(m, 1H), 2.77-2.59(m, 2H); 13C NMR (100MHz, CDCl3) δ162.4, 144.4, 133.3, 132.83, 132.80, 132.75, 132.73, 132.68, 13 2.66, 131.7, 131.64, 131.62, 131.57, 131.5, 131.47, 131.2, 131.1, 131.0, 130.8, 130.7 ,129.8,129.7,129.5,129.3,129.1,128.94,128.90,128.81,128.76,128.6,127.5,89 .6, 87.7, 87.63, 87.59, 87.56, 75.6, 75.5, 63.62, 63.56, 40.31, 40.26; HRMS(ESI)calcd forC 40 H 35 N3O7P2Na[M+Na] + 754.1842, found 754.1841.

[0166] Example 28 Compound III-28

[0167] According to route 1, the donor I-4 (80 mg, 0.11 mmol) and the acceptor II-14 (19 mg, 0.17 mmol) were dissolved in dry MeCN. Under inert gas protection, the temperature was raised to 50°C, and BSTFA (135 μL, 0.51 mmol) was added. After the solution turned from turbid to clear, the solvent was dried and added to dry CH3CN (2.0 mL). The reaction was catalyzed by PPh3AuNTf2 (8.2 mg in 3.3 mL dry DCE, 0.011 mmol) to obtain the white syrup obtained after separation of the crude product by flash column chromatography, which was the pure product of III-28 (63 mg, 91%, α only): [α] D 20 =-42.4 (c = 1.0 in CHCl3); 1 H NMR (400MHz, CDCl3) δ8.22 (s, 1H), 7.78-7.69 (m, 4H), 7.67-7.56 (m, 4H), 7.54-7.48 (m, 2H), 7.47-7.31 (m, 10H), 7.22 (s, 1H), 6.28 (s, 1H), 6.11 (dd, J=5.5, 2.4Hz, 1H), 5.07-4.94 (m, 2H), 4.10-3.93 (m, 2H), 2.65-2.51 (m, 2H); 13C NMR (100MHz, CDCl3) δ166.5, 155.0, 153.9, 132.80, 132.77, 132.62, 132.59, 131. 7, 131.60, 131.59, 131.57, 131.48, 131.46, 131.4, 131.2, 131.12, 131.10, 131.0, 130.7, 129.8, 129.7, 129.6, 129.4, 129.0, 128.85, 128.82, 128.71, 128.68, 88.8 , 87.30, 87.27, 87.23, 87.20, 75.5, 75.4, 63.5, 63.4, 40.3, 40.2; HRMS(ESI)calcd forC 32 H 30 N4O6P2Na[M+Na] + 651.1533, found 651.1523.

[0168] The following are in vitro cytotoxicity tests and results of some compounds of the present invention:

[0169] Experimental instruments and materials:

[0170] A microplate reader (Thermo Multiskan FC 357-910480) was purchased from ThermoFisher (USA). Human glioblastoma cells (LN229) and human neuroblastoma cells (SH-SY5Y) were purchased from the Cell Culture Center, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences (Shanghai, China). MTT, fetal bovine serum (FBS), and incomplete culture medium (Dulbecoo's modified Eagle's medium, DMEM) were purchased from Jiangsu KeyGen Biotech Co., Ltd.

[0171] Experimental methods:

[0172] (1) Cell culture: LN229 and SH-SY5Y cells are adherent cells and were cultured in DMEM medium containing 10% fetal bovine serum in an incubator at 37°C and 5% CO2.

[0173] (2) Seeding: When the cells reached the logarithmic growth phase and grew to a density of about 80%, they were digested with 0.25% trypsin and pipetted into single cells for later use. LN229 cells were dispersed into 5 × 10 3 SH-SY5Y cells were dispersed in DMEM incomplete medium at a density of 4*10 3The cells were seeded at a density of 100 μL / mL in a 96-well cell culture plate, with each well containing 100 μL of cell suspension, and cultured in an incubator at 37°C and 5% CO2.

[0174] (3) Dosing: After 12 hours of incubation, the culture medium in the wells was discarded and the test compound was diluted to a target dosing concentration of 100 μM using DMEM incomplete medium. 100 μL of the compound dilution was added to each well of a 96-well cell culture plate. The blank control group was treated with the same amount of incomplete medium. Three replicate wells were set up for each concentration group and incubated in an incubator at 37°C and 5% CO2.

[0175] (4) Reading: After incubation for another 24 hours, add 20 μL of MTT solution to each well and continue incubation at 37°C and 5% CO2. After 4 hours, discard the airborne liquid and add 100 μL of DMSO solution to each well to dissolve the formazan crystals. After shaking for 2 minutes, read the absorbance data of the 96-well plate at 480 nm using a microplate reader. The data are expressed as Mean ± SD. Based on this, the cell viability is calculated using the following formula:

[0176]

[0177] Among them, OD test Represents the absorbance of the test compound administration group, OD blank Represents the background absorption of 100 μL DMSO solution in the plate, OD control Represents the absorbance of the blank control group.

[0178] Table 1 Inhibitory effect of target compounds on SH-SY5Y and LN229

[0179]

[0180] Compound III-17 was selected and IC was further performed at different concentrations (0.32, 1.6, 8, 20, 40, 50, 100, 200 and 1000 μM). 50 Inhibitory concentration determination. Absorbance was read at 492 nm using a microplate reader. Data were analyzed using Prism 7.0 software (GraphPad software) using a nonlinear regression analysis model to calculate the half-inhibitory concentration. Preliminary screening and half-inhibitory concentration values were calculated using Prism 7.0. Data are expressed as mean ± SD (n = 3).

[0181] Table 2 Inhibitory activity of preferred compound III-17 against SH-SY5Y and LN229

[0182]

[0183] *All data are the average of three parallel experiments, in the form of Mean ± SD (n = 3)

[0184] Results analysis: From the activity test results, it can be concluded that only the compounds containing DPP showed significant inhibitory effects, which indicates that the DPP fragment may have some type of anti-tumor effect. As shown in Table 2, the most active compound III-17 had a significant inhibitory effect on SH-SY5Y (IC 50 =5.30±4.21 μM) and LN229 (IC 50 =9.97±1.53μM) showed strong anti-proliferative activity, suggesting that III-17 can be used as a lead compound for further development of anti-tumor drugs for central nervous system tumors.

[0185] In order to further understand the structure-activity relationship (SAR) of α-nucleoside III-17, the present invention conducted IC experiments on it with β-isomers S8 and S9 with natural β-oriented glycosidic bonds and the DPP-free analog S7. 50 Comparison of tests. Antiproliferation assays showed that the two β-isotopes S8 and S9 had no inhibitory effect on these two CNS tumor cell lines, indicating that the non-natural αv configuration is necessary for activity. Removal of the DPP group from III-17 significantly reduced activity, resulting in an IC of α-nucleoside S7. 50 These results indicate that both the α-configuration and the DPP group are crucial for maintaining the activity of the preferred compound III-17.

[0186] The preferred compounds involved in the present invention have good inhibitory activity against tumor cells such as SH-SY5Y and LN229, and have good application prospects in the anti-tumor field.

Claims

1. A method for the direct synthesis of α-2′-deoxynucleosides with high stereoselectivity, characterized in that: The general reaction formula is as follows: Wherein, Formula I is a glycosyl donor; R1 is a hydroxyl substituent at position 5 selected from 2-diphenylphosphonoacetyl, 2-diphenylphosphonopropionyl, and 2-diphenylphosphonyl; R2 is a hydroxyl substituent at position 3 selected from benzyl and 2-diphenylphosphonyl; LG is a leaving group selected from o-alkynyl benzoate; Nu in Formula II is a glycosyl acceptor, which is a purine base or a pyrimidine base; Nu in Formula III is the residue after the reaction of a purine base or a pyrimidine base; The catalyst is selected from PPh3AuNTf2; Molecular sieves are MS; The reaction temperature is -25°C to 50°C.

2. The method for directly synthesizing α-2′-deoxynucleosides with high stereoselectivity according to claim 1, characterized in that: When the glycosyl acceptor is a purine base, the method specifically includes the following steps: (1) A glycosyl donor represented by formula I, a glycosyl acceptor represented by formula II, and a molecular sieve are added to an organic solvent under the protection of an inert gas. The reaction system is then placed at -25°C to 50°C, a catalyst is added, and the reaction is carried out. After the reaction is complete, a crude deoxynucleoside product represented by formula III is obtained.

3. The method for directly synthesizing α-2′-deoxynucleosides with high stereoselectivity according to claim 1, wherein: When the glycosyl acceptor is a pyrimidine base, the method specifically comprises the following steps: (1) Silylation: The glycosyl donor represented by Formula I and the glycosyl acceptor represented by Formula II are added to acetonitrile, and then N, O-bis(trimethylsilyl)trifluoroacetamide is added at 40-60°C. The reaction is carried out under inert gas protection until the solution is clear. (2) removing acetonitrile, then placing the reaction system at -25°C to 50°C, adding an organic solvent, a catalyst and a molecular sieve, and reacting. After the reaction is complete, a crude deoxynucleoside product represented by formula III is obtained.

4. The method for directly synthesizing α-2′-deoxynucleosides with high stereoselectivity according to any one of claims 2 to 3, characterized in that: The next step is to filter, vacuum concentrate, and column chromatograph the crude deoxynucleoside product represented by Formula III to obtain a pure deoxynucleoside product represented by Formula III.

5. The method for directly synthesizing α-2′-deoxynucleosides with high stereoselectivity according to claim 1, characterized in that: The organic solvent is one or more of dichloromethane, toluene, trifluorotoluene, dichloroethane, ether or acetonitrile.

6. The method for directly synthesizing α-2′-deoxynucleosides with high stereoselectivity according to claim 1, characterized in that: The glycosyl donor represented by formula I is selected from the following compounds represented by any one of the structures I-1 to I-4:

7. The method for directly synthesizing α-2′-deoxynucleosides with high stereoselectivity according to claim 1, characterized in that: The Nu in formula II is selected from the compounds shown in any one of the structures shown in the following II-1 to II-15:

8. The method for directly synthesizing α-2′-deoxynucleosides with high stereoselectivity according to claim 1, characterized in that: The deoxynucleoside product represented by formula III is selected from the compounds represented by any one of the structures shown in the following III-1 to III-28:

9. A compound of formula IV or a pharmaceutically acceptable salt thereof: R1 is 2-diphenylphosphonyl; R2 is 2-diphenylphosphonyl; Nu is selected from the following groups:

10. Use of the compound of formula IV according to claim 9 or a pharmaceutically acceptable salt thereof in the preparation of a drug for treating central nervous system tumors.

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