Photoresponsive degradable polymer and preparation method thereof

Abstract

The invention belongs to the technical field of photodegradable polymers, and discloses a photoresponsive degradable polymer and a preparation method thereof. The method comprises the following steps: carrying out an enyne double decomposition reaction on a monomer containing a photodegradable group, or carrying out a reaction on the monomer containing the photodegradable group and an enyne monomer without a photoresponse fragment through block copolymerization or random copolymerization to obtain the photoresponse degradable polymer, the monomer containing the photodegradable group is an acyclic tension monomer. According to the invention, the photo-responsive degradable polymer with high molecular weight and controllable polymerization effect is successfully obtained through an alkene-alkyne cascade metathesis reaction; and the method disclosed by the invention has a relatively good effect.

Description

Technical Field

[0001] The invention belongs to the technical field of organic chemistry and polymer chemistry, and discloses a light-responsive degradable polymer and a preparation method thereof. Background Art

[0002] At present, common polymerization methods include cationic polymerization, anionic polymerization and free radical polymerization (such as atom transfer radical polymerization, ATRP), etc., and have been widely developed and utilized. The 2005 Nobel Prize in Chemistry was awarded to Yves Chauvin, Robert H. Grubbs and Richard R. Schrock in recognition of the three scientists who developed the metathesis method in organic synthesis. Ring-Opening Metathesis Polymerization (ROMP) has been widely studied as a type of olefin metathesis. It has milder reaction conditions, faster reaction speed, better functional group tolerance, and is a living polymerization. Moreover, unlike other traditional polymerizations, the polymer obtained by ROMP still retains unsaturated double bonds. Ring-opening metathesis polymerization is essentially an olefin metathesis reaction. After polymerization, olefin polymers containing double bonds are obtained, and more functional polymers can be obtained by post-polymerization modification, hydrogenation and other means.

[0003] Ring-opening metathesis polymerization mostly uses norbornene as a monomer, extending its application in different fields. At present, preliminary explorations have been made in molecular recognition, drug delivery, fluorescence imaging, biomaterials, etc. However, the polyolefins with a full carbon skeleton are not easy to degrade, causing certain pollution and harm to the environment. With its development, many scientists have developed some acid-base degradable polymers, but most of them require strong acid or strong base conditions, which have certain limitations.

[0004] The present invention provides a photodegradable polymer, which uses alkene and alkyne cascade metathesis as a polymerization method, introduces degradation groups that can respond to different wavelengths, and achieves degradation in different wavelength bands under mild conditions. Summary of the invention

[0005] In order to overcome the shortcomings and deficiencies of the prior art, the object of the present invention is to provide a photoresponsive degradable polymer and a method for preparing the same. The present invention solves the problem of single polymer degradability, and synthesizes photoresponsive polymers by metathesis of ene and alkyne, thereby expanding the scope of photodegradable polymers. In addition, it is difficult for the existing monomer main chain to accommodate the photoresponsive module, and the cascade ene and alkyne metathesis polymerization has no requirements for ring tension, and the method of the present invention can overcome this problem.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A method for preparing a photoresponsive degradable polymer comprises the following steps:

[0008] The monomer containing the photodegradable group is subjected to an ene-alkyne metathesis reaction to obtain a photoresponsive degradable polymer;

[0009] The monomer containing the photodegradable group is

[0010] R1, R2 are photodegradable groups, such as o-nitrobenzyl, anthracene, pyrene, and coumarin derivatives;

[0011] R1 is specifically

[0012]

[0013] R2 is specifically Or the monomer containing the photodegradable group is

[0014]

[0015] -R4-R3, R5 is a group containing -NH-C(O)-, and R6 is O or -OC(O)-.

[0016] The -R4-R3 is specifically

[0017] The phenylene group is substituted at the ortho, meta or para position. R5 is -CH2-NH-C(O)-CH2-.

[0018] The monomer containing a photodegradable group is specifically one or more of the following structural compounds:

[0019]

[0020]

[0021] The monomer containing a photodegradable group is a monomer without ring strain.

[0022] The catalyst for the olefin and acetylene metathesis reaction is a Grubbs third-generation catalyst, preferably benzylene-[1,3-bis(trimethylphenyl)-2-imidazolinylidene]-dichloro-bis(3-chloropyridine)ruthenium, or benzylene-[1,3-bis(trimethylphenyl)-2-imidazolinylidene]-dichloro-bipyridine ruthenium.

[0023] The solvent of the reaction is THF or DCM; the reaction time is ≥5 min. After the reaction is completed, ethyl vinyl ether is added to terminate the reaction, triethylamine is added or not (triethylamine is not added when the monomer M8 or M9 is self-polymerized), and the solvent is removed.

[0024] The concentration of the monomer containing photodegradable groups in the solvent is 0.01-0.2 M. The molar ratio of the catalyst used in the reaction to the monomer containing photodegradable groups is 1:(20-100).

[0025] The monomer containing the photodegradable group is of formula I, and the general formula of the photoresponsive degradable polymer is The wavy line on the left connects the groups from the catalyst;

[0026] The monomer containing the photodegradable group is of formula II, and the general formula of the photoresponsive degradable polymer is The wavy line on the left connects the groups from the catalyst;

[0027] The monomer containing the photodegradable group is of formula III, and the general formula of the photoresponsive degradable polymer is The wavy line on the left connects the groups from the catalyst;

[0028] The monomer containing the photodegradable group is of formula IV, and the general formula of the photoresponsive degradable polymer is The wavy line on the left connects the groups from the catalyst.

[0029] The ene-alkyne metathesis reaction can also be a block copolymerization or random copolymerization of monomer M1 and an ene-alkyne monomer without a photoresponsive fragment to obtain a photoresponsive degradable polymer. The catalyst of the reaction is a Grubbs third generation catalyst, such as G3 or G3-Cl.

[0030] The block copolymerization refers to reacting the ene-yne ​​monomer without a photoresponsive fragment under a protective atmosphere under the action of a catalyst, and then adding the monomer M1 for copolymerization to obtain a photoresponsive degradable polymer. The reaction temperature is room temperature. The ene-yne ​​monomer without a photoresponsive fragment is preferably the following formula V.

[0031] The random copolymerization refers to mixing the monomer M1 with the ene-yne ​​monomer without a photoresponsive segment under a protective atmosphere, and copolymerizing them under the action of a catalyst to obtain a photoresponsive degradable polymer. The ene-yne ​​monomer without a photoresponsive segment is preferably the following formula VI.

[0032] The ene-yne ​​monomer without a photoresponsive segment is

[0033]

[0034] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0035] 1. The present invention successfully obtains a type of light-responsive degradable polymer with high molecular weight and controllable polymerization effect through alkene and alkyne cascade metathesis reaction.

[0036] 2. In the method of the present invention, both the polymerization of small ring monomers and the polymerization of large ring monomers have good effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figures 1 to 14 They are the GPC curves of the polymerization of M1~M2, M4~M15 respectively; Figure 1 Corresponding to M1 aggregation, Figure 2 Corresponding to M2 aggregation, Figure 3 Corresponding to M4 aggregation, Figure 4 Corresponding to M5 aggregation, Figure 5 Corresponding to M6 aggregation, Figure 6 Corresponding to M7 aggregation, Figure 7 Corresponding to M8 aggregation, Figure 8 Corresponding to M9 aggregation, Fig. 9 Corresponding to M10 aggregation, Fig.10 Corresponding to M11 aggregation, Fig.11 Corresponding to M12 aggregation, Fig.12 Corresponding to M13 aggregation, Fig.13 Corresponding to M14 aggregation, Fig.14 Corresponding to M15 aggregation;

[0038] Fig.15 is the GPC curve of block polymerization;

[0039] Fig.16 is the GPC curve of random copolymerization;

[0040] Fig.17 GPC curve of degradation of P1;

[0041] Fig.18 The control group P Bn GPC curve of degradation;

[0042] Fig.19 is the GPC curve of P10 degradation;

[0043] Fig. 20 is the GPC curve of block copolymer degradation;

[0044] Fig.21 This is the GPC curve of random copolymer degradation. DETAILED DESCRIPTION

[0045] The present invention is further described in detail below in conjunction with specific examples, but the embodiments of the present invention are not limited thereto. All the solvents used in the polymerization of the present invention are from a solvent purification system. Ultraviolet lamp: GHUV-365.

[0046] The catalyst is prepared by exchanging ligands between commercially available Grubbs2-generation catalyst and pyridine to obtain Grubbs3-generation catalyst, i.e. G3. The catalyst is then exchanged between commercially available Grubbs3-Cl catalyst and 3-chloropyridine to obtain Grubbs3-Cl catalyst, i.e. G3-Cl.

[0047] The preparation method of the monomer containing photodegradable groups of the structural formula I comprises the following steps: furfuryl alcohol undergoes Achmatowicz reaction under the action of m-CPBA to obtain a six-membered ring hemiacetal compound 1; the compound is dissolved in anhydrous DCM, Boc2O and DMAP are added to obtain a Boc-protected compound 2; different nucleophilic reagents are added, and Tsuji-Trust reaction is carried out under the action of Pd2(dba)3 to obtain a compound 3 substituted with different photoresponsive groups; NaBH4 and CeCl3 are then added to carry out Luche reduction to obtain a compound 4; and finally, a light-nobu reaction is carried out with propargylamine substituted with Mes under the joint action of DIAD (or DEAD) and PPh3 to obtain a monomer containing two chiral centers and a clear stereo configuration. See monomers M1-M7.

[0048] The reaction equation is

[0049]

[0050] The method for preparing a monomer containing a photodegradable group with a structural formula of formula II comprises the following steps: xylose is reacted under the action of Et3N, DMAP and acetic anhydride to obtain a tetraacetyl-substituted xylose derivative; HBr is added to cause a bromination reaction, and then an intramolecular elimination reaction occurs under the action of DBU to obtain an intermediate 5; with the addition of different nucleophilic reagents, under the condition of boron trifluoride as Lewis acid, a Ferrier rearrangement occurs to obtain acrylone intermediate 6; and a monomer with a clear stereo configuration can be obtained through a Luche reaction and a Mitsunobu reaction.

[0051] The preparation methods of monomers M8-M9 are similar, and the reaction equation is:

[0052]

[0053] The preparation methods of the monomers M11-13 containing photodegradable groups are similar to those of M10.

[0054] The monomers M14 and M15 containing photodegradable groups can be prepared by existing methods.

[0055] Example 1

[0056] Synthesis of monomer M1:

[0057] (1) Preparation of Compound 2

[0058] Compound 1 (6.0mmol, 1.0eq), 2-nitrobenzyl alcohol (10.8mmol, 1.8eq) and PPh3 (0.6mmol, 0.1eq) were dissolved in anhydrous DCM (12mL), and Pd2(dba)3 (0.15mmol, 0.025eq) was added at 0°C after deoxygenation, and the mixture was reacted for 3h at room temperature. After the reaction was completed, saturated sodium bicarbonate aqueous solution was added to terminate the reaction, and the mixture was extracted with DCM and dried with Na2SO4. After the organic phase was concentrated, the product was directly purified by column chromatography, and the polarity of the eluent was PE:EA=10:1 to obtain compound 2. Yield: 1.32g, 88%, the product was a yellow oily liquid.

[0059] The structure of compound 1: The structure of compound 2 is

[0060] The characterization test of compound 2 is as follows:

[0061] HRMS(ESI)[M+H] + calcd.for C 12 H 12 NO5,249.0637,found,249.0643.

[0062] 1 H NMR (400MHz, CDCl3): δ8.09(d,J=8.2Hz,1H),7.73(d,J=7.8Hz,1H),7.66(t,J=7.6Hz,1H),7.49(t,J=7.8Hz,1H),6.95(dd,J=10.3,3.3Hz,1H) ,6.20(d,J=10.3Hz,1H),5.38(d,J=3.3Hz,1H),5.25(d,J=14.3Hz,1H),5.08(d,J=14.3Hz,1H),4.47(d,J=17.0Hz,1H),4.15(d,J=16.9Hz,1H).

[0063] 13 C NMR (100MHz, CDCl3): δ194.45,147.47,143.75,133.89,133.57,129.16,128.76,128.36,125.09,93.41,67.99,66.63.

[0064] (2) Preparation of Compound 3

[0065] Compound 2 (5.28 mmol, 1.0 eq) and CeCl3 (2.11 mmol, 0.4 eq) were dissolved in DCM (5 mL) and MeOH (5 mL) and cooled to -78°C, NaBH4 (0.22 g, 5.81 mmol, 1.1 eq) was added and reacted at -78°C for 4 h; after the reaction was completed, saturated sodium bicarbonate aqueous solution was added to terminate the reaction, DCM was extracted, Na2SO4 was dried, and the organic phase was concentrated and directly purified by column chromatography. The polarity of the eluent was PE:EA=6:1 to obtain compound 3. Yield: 1.18 g, 89%, the product was a white solid. The melting point of compound 3: 95-97°C.

[0066] The structure of compound 3:

[0067] HRMS(ESI)[M+H] + calcd.for C 12 H 14 NO5,252.0866,found,252.0859.

[0068] 1 H NMR (400MHz, CDCl3): δ8.05(d,J=8.2Hz,1H),7.76(d,J=7.8Hz,1H),7.63(t,J =7.6Hz,1H),7.44(t,J=7.8Hz,1H),6.06(d,J=10.3Hz,1H),5.83(dt,J=10.5, 2.0Hz,1H),5.17(d,J=14.6Hz,1H),5.07(s,1H),4.97(d,J=14.6Hz,1H),4.27 (t,J=6.8Hz,1H),3.81(dd,J=11.0,5.3Hz,1H),3.69(dd,J=11.0,8.2Hz,1H).

[0069] 13 C NMR (100MHz, CDCl3): δ147.61,134.47,133.69,133.64,129.24,128.33,127.15,124.84,94.66,67.17,53.93,53.12.

[0070] (3) Preparation of M1

[0071] Compound 3 (4.7 mmol, 1.0 eq), Mes-substituted propargylamine (4.7 mmol, 1.0 eq) and PPh3 (7.52 mmol, 1.6 eq) were dissolved in anhydrous THF (63 mL), DEAD (1.23 g, 1.5 eq) was added at 0°C and reacted at room temperature for 24 h. After the organic phase was concentrated, the product was directly purified by column chromatography. The polarity of the eluent was PE:EA=10:1. Yield: 1.92 g, 87%, the product was a yellow solid. The melting point of monomer M1: 74-76°C. Mes-substituted propargylamine: The structure of M1 is

[0072] The characterization tests for M1 are as follows:

[0073] HRMS(ESI)[M+H] + calcd.for C 24 H 27 N2O6S,470.1512,found,470.1512.

[0074] 1 H NMR (400MHz, CDCl3): δ8.05 (dd, J=8.2, 1.3Hz, 1H), 7.70 (d, J=7.8Hz, 1H), 7.62 (td, J=7.6,1.3Hz,1H),7.54-7.36(m,1H),6.95(s,2H),6.12(ddd,J=10.1,3.2,1.5Hz,1H ),5.96(dd,J=10.1,5.0Hz,1H),5.20-5.07(m,2H),4.95(d,J=14.5Hz,1H),4.35-4. 11(m,2H),4.11-3.89(m,3H),2.62(s,6H),2.30(s,3H),2.20-1.99(t,J=2.4Hz,1H).

[0075] 13 C NMR (100MHz, CDCl3): δ147.67,143.13,140.59,134.23,133.68,132.47,132.21,130.59,129 .21,128.43,126.71,124.91,93.19,80.18,71.73,66.97,62.48,48.19,33.36,22.93,22.12.

[0076] Example 2

[0077] Preparation of monomer M8:

[0078] (1) Preparation of Compound 6

[0079] Compound 5 (3.0 mmol, 1.0 eq) and 2-nitrobenzyl alcohol 1 (3.6 mmol, 1.2 eq) were dissolved in anhydrous DCM (12 mL), and BF3·OEt2 (48%) (6.0 mmol, 2.0 eq) was added at 0°C. The mixture was reacted for 30 min in an ice bath. After the reaction was completed, a saturated aqueous sodium bicarbonate solution was added to terminate the reaction, and the mixture was extracted with DCM and dried with Na2SO4. After the organic phase was concentrated, the product was directly purified by column chromatography. The polarity of the eluent was PE:EA=5:1. Yield: 0.62 g, 83%, and the product was an orange oily liquid.

[0080] Compound 5: Compound 6:

[0081] HRMS(ESI)[M+H] + calcd.for C 12 H 12 NO5,250.0710,found,250.0709.

[0082] 1 H NMR (400MHz, CDCl3): δ8.16-7.99(m,1H),7.75(d,J=7.8Hz,1H),7.63(t,J= 7.6Hz,1H),7.43(t,J=7.8Hz,1H),7.10(ddd,J=10.5,3.9,1.8Hz,1H),6.15( dq,J=10.5,2.3Hz,1H),5.25(dd,J=15.2,3.4Hz,1H),5.06(dd,J=15.2,3.4 Hz,1H),4.94(s,1H),4.72-4.50(m,1H),4.32(ddd,J=19.2,3.8,1.9Hz,1H).

[0083] 13 C NMR (100MHz, CDCl3): δ188.16,148.40,148.36,147.06,134.03,133.68,128.68,128.39,124.86,124.74,124.71,97.48,67.22,59.98.

[0084] (2) Preparation of Compound 7

[0085] Compound 6 (2.2 mmol, 1.0 eq) and CeCl3 (0.88 mmol, 0.4 eq) were dissolved in DCM (4.5 mL) and MeOH (4.5 mL). NaBH4 (92 mg, 2.42 mmol, 1.1 eq) was added at -78°C and reacted for 4 h at -78°C. After the reaction was completed, saturated sodium bicarbonate aqueous solution was added to terminate the reaction, extracted with DCM, dried with Na2SO4, and the organic phase was concentrated and directly purified by column chromatography. The polarity of the eluent was PE:EA=4:1. Yield: 0.5 g, 90%, the product was a white solid. Melting point: 98-100°C.

[0086] Compound 7:

[0087] HRMS(ESI)[M]calcd.for C 12 H 13 NO5,251.0794,found,251.0794.

[0088] 1 H NMR (400MHz, CDCl3): δ8.09(dd,J=8.2,1.3Hz,1H),7.84-7.71(m,1H),7.66(td,J=7.6,1.3Hz,1H),7.57-7.41(m,1H),5.86(dd,J=10.6 ,2.2Hz,1H),5.83-5.76(m,1H),5.25(d,J=14.8Hz,1H),5.07(d,J=14.9Hz,1H),5.02(d,J=3.9Hz,1H),4.27(s,1H),4.22-4.02(m,2H).

[0089] 13 C NMR (100MHz, CDCl3): δ134.13,133.89,128.98,128.52,127.43,126.04,125.02,96.89,66.72,64.41,60.85.

[0090] (3) Preparation of M8

[0091] Compound 7 (0.45 g, 1.8 mmol, 1.0 eq), Mes-substituted propargylamine (0.43 g, 1.8 mmol, 1.0 eq) and PPh3 (0.76 g, 2.88 mmol, 1.6 eq) were dissolved in anhydrous THF (24 mL, 0.075 M), DIAD (0.55 g, 0.53 mL, 2.7 mmol, 1.5 eq) was added at 0°C and reacted at room temperature for 24 h. After concentrating the organic phase, the product was directly purified by column chromatography, and the polarity of the eluent was PE:EA=6:1. Yield: 0.74 g, 88%, the product was a yellow solid. Melting point: 92-94°C.

[0092] M8:

[0093] HRMS(ESI)[M]calcd.for C 24 H 26 N2O6S,470.1512,found,470.1514.

[0094] 1 H NMR (400MHz, CDCl3): δ8.09 (dd, J=8.2, 1.3Hz, 1H), 7.72-7.67 (m, 1H), 7.63 (t d,J=7.6,1.3Hz,1H),7.48-7.42(m,1H),6.93(s,2H),6.33-6.06(m,1H),5.75 -5.56(m,1H),5.29-5.10(m,2H),4.94(d,J=15.4Hz,1H),4.34-4.13(m,4H),4 .04(dd,J=18.4,2.5Hz,1H),2.62(s,6H),2.28(s,3H),2.11(t,J=2.4Hz,1H).

[0095] 13 C NMR (100MHz, CDCl3): δ147.13,143.08,140.67,134.42,133.94,132.56,132.19,131.42,128 .72,128.18,124.90,120.80,98.92,80.12,71.70,66.31,59.35,52.81,32.64,22.96,21.12.

[0096] Example 3

[0097] Preparation of Monomer M10

[0098] (1) Preparation of Compound 8

[0099] L-serine (95.2mmol, 1.0eq) was dissolved in methanol (96mL, 1M), thionyl chloride (285.6mmol) was added at 0℃, and the mixture was reacted at 65℃ for 18h. The organic phase was dried by vortexing, dissolved in anhydrous DCM (350mL), and Et3N (228.5mmol, 2.4eq) was added. After 5min, p-toluenesulfonyl chloride (104.7mmol, 1.1eq) was added under ice bath conditions and the mixture was reacted at room temperature for 18h. After the reaction was completed, a saturated sodium chloride aqueous solution was added to terminate the reaction, and the mixture was extracted with DCM and dried over Na2SO4. After the organic phase was concentrated, the crude product and imidazole (190.4mmol, 2.0eq) were dissolved in anhydrous DMF (300mL), and TBSCl (142.8mmol) was added at 0℃. After the reaction was completed, the mixture was extracted with EtOAc and dried over Na2SO4. The organic phase was dried by spin drying, and the crude product, K2CO3 (285.6mmol), TBAI (19.0mmol) and 3-bromopropyne (152.3mmol, 1.6eq) were dissolved in CH3CN (476mL). After the reaction was completed, the product was filtered through diatomaceous earth, and the organic phase was concentrated and directly purified by column chromatography (Compound 8). The polarity of the eluent was PE:EA=4:1. Yield: 36.7g, 85%, the product was a yellow solid. Melting point: 46-48°C.

[0100] Compound 8:

[0101] HRMS(ESI)[M+H] + calcd.for C 22 H 36 NO5SSi,454.2078,found,454.2074.

[0102] 1 H NMR (400MHz, CDCl3): δ6.92(s,2H),4.46(t,J=4.4Hz,1H),4.33(d,J=2.4Hz,2H),4.21(dd,J=10.5,3.9Hz,1H),4.13(dd ,J=10.5,5.0Hz,1H),3.64(s,3H),2.60(s,6H),2.27(s,3H),2.03(t,J=2.4Hz,1H),0.84(s,9H),0.02(d,J=7.8Hz,6H).

[0103] 13C NMR (100MHz, CDCl3): δ169.84,142.97,140.78,132.43,132.06,80.24,71. 19,62.94,59.94,52.14,34.48,25.73,22.96,21.06,18.16,-5.59,-5.84.

[0104] (2) Preparation of Compound 9

[0105] Compound 8 (33.06 mmol, 1.0 eq) was dissolved in anhydrous DCM (143 mL) and cooled to -83°C, diisobutylaluminum hydride (46.28 mmol, 1.4 eq, 1.0 M / hexane) was added, and after 2.5 h, isopropanol (20 mL) and Rochelle salt (50 mL) were added, stirred at room temperature overnight, extracted with EtOAc, and dried over Na2SO4. Ethyl diphenylphosphine acetate (36.3 mmol, 1.1 eq) was dissolved in anhydrous THF (150 mL), and 60% NaH (1.46 g, 36.63 mmol, 1.0 eq) was added at 0°C. After 0.5h, the reaction solution was cooled to -78°C; the crude product (15.7g, 36.3mmol, 1.1eq) was dissolved in 100mL of anhydrous THF and added thereto, reacted at -78°C for 1h, and then continued to react at -10°C for 1h. After the reaction was completed, a saturated aqueous solution of ammonium chloride was added to terminate the reaction, extracted with EtOAc, dried with Na2SO4, and the organic phase was concentrated and directly purified by column chromatography. The polarity of the eluent was PE:EA=10:1. Yield: 10.3g, 63%, the product was a colorless oily liquid.

[0106] Compound 9:

[0107] HRMS(ESI)[M+H] + calcd.for C 25 H 39 NO5SSi,494.2391,found,494.2394.

[0108] 1H NMR (400MHz, CDCl3): δ6.87 (s, 2H), 6.67 (dd, J=11.7, 8.6Hz, 1H), 5.74 (dd, J=1 1.7,1.3Hz,1H),5.35-5.23(m,1H),4.44(dd,J=18.5,2.4Hz,1H),4.21(dd,J=1 8.5,2.4Hz,1H),4.08(q,J=7.1Hz,2H),3.96-3.74(m,2H),2.54(s,6H),2.26(t ,J=2.5Hz,1H),2.24(s,3H),1.21(t,J=7.1Hz,3H),0.81(s,9H),-0.04(s,6H).

[0109] 13 C NMR (100MHz, CDCl3): δ165.31,145.11,142.59,140.66,132.50,131.88,120.60,80.62 ,72.50,63.36,60.22,56.28,32.56,25.80,22.81,20.96,18.19,14.18,-5.51,-5.78.

[0110] (3) Preparation of Compound 10

[0111] Compound 9 (42.0 mmol, 1.0 eq) was dissolved in anhydrous DCM (140 mL), and diisobutylaluminum hydride (105.0 mmol, 2.5 eq, 1.0 M / hexane) was added at -50°C. After 0.5 h, isopropanol (40 mL) and Rochelle's salt (150 mL) were added, and the mixture was stirred overnight at room temperature, extracted with EtOAc, dried with Na2SO4, and the organic phase was concentrated and directly purified by column chromatography (Compound 10), and the polarity of the eluent was PE:EA=5:1. Yield: 17.0 g, 90%, and the product was a colorless liquid.

[0112] Compound 10:

[0113] HRMS(ESI)[M+H] + calcd.for C 23 H 38 NO4SSi,452.2285,found,452.2288.

[0114] 1H NMR (400MHz, CDCl3): δ6.95(s,2H),6.21-5.76(m,2H),4.74-4.58(m,1H),4.17-4.07(m,2H),4.00(dd,J=18.5,2.5Hz,1H), 3.96-3.89(m,1H),3.81-3.68(m,2H),2.61(s,6H),2.29(s,3H),2.21(t,J=2.5Hz,1H),0.84(s,9H),0.01(d,J=1.1Hz,6H).

[0115] 13 C NMR (100MHz, CDCl3): δ143.05,140.71,133.25,132.59,132.09,126.86,80.03 ,72.57,64.23,58.04,54.78,32.71,25.89,22.85,21.02,18.34,-5.44,-5.56.

[0116] (4) Compound 12

[0117] Compound 11 (44.0 mmol, 1.1 eq), 3,4-dimethoxybenzyl alcohol (40.0 mmol, 1.0 eq), EDCI (80.0 mmol, 2.0 eq) and DMAP (20.0 mmol, 0.5 eq) were dissolved in anhydrous THF (134 mL) and reacted at room temperature for 24 h. After the reaction was completed, EtOAc was extracted and dried over Na2SO4. After the organic phase was concentrated, the product was directly purified by column chromatography. The polarity of the eluent was PE:EA=22:1. Yield: 19.14 g, 86%, the product was a white solid.

[0118] Compound 11: Compound 12:

[0119] Melting point: 98-100℃.

[0120] HRMS(ESI)[MH] - calcd.for C 23 H 22 NO6S,440.1173,found,440.1176.

[0121] 1H NMR (400MHz, CDCl3): δ8.50 (t, J=1.7Hz, 1H), 8.22 (dd, J=7.8, 1.4Hz, 1H), 8.01 (ddd,J=7.8,1.9,1.2Hz,1H),7.55(t,J=7.8Hz,1H),7.21(m,3H),7.15(m,2H), 7.03(dd,J=8.2,2.0Hz,1H),6.98(d,J=2.0Hz,1H),6.87(d,J=8.2Hz,1H),5.31 (s,2H),5.06(t,J=6.1Hz,1H),4.15(d,J=6.1Hz,2H),3.89(s,3H),3.88(s,3H).

[0122] 13 C NMR (100MHz, CDCl3): δ165.06,149.46,149.14,140.90,135.96,133.69,131.54,131.27,129.47 ,128.80,128.35,128.08,128.01,127.96,121.79,112.20,111.21,67.64,56.07,56.05,47.41.

[0123] (8) Preparation of Compound 15

[0124] Compound 10 (8.0 mmol, 1.0 eq), compound 12 (8.8 mmol, 1.1 eq) and PPh3 (10.4 mmol, 1.3 eq) were dissolved in anhydrous THF (106 mL), and DEAD (9.6 mmol, 1.2 eq) was added at 0°C. The reaction was allowed to proceed at room temperature for 24 h. After the reaction was completed, the organic phase was concentrated and the product (compound 15) was directly purified by column chromatography. The polarity of the eluent was PE:EA=6:1. Yield: 5.95 g, 85%, the product was an orange oily liquid.

[0125] Compound 15:

[0126] HRMS(ESI)[M+H] + calcd.for C 46 H 59 N2O9S2Si,875.3426,found,875.3425.

[0127] 1H NMR (400MHz, CDCl3): δ8.48(d,J=1.9Hz,1H),8.26(d,J=7.7Hz,1H),7.98(dd,J=8.0,1.7Hz,1H),7.60(t,J=7.7Hz ,1H),7.31-7.19(m,5H),7.04(dd,J=8.1,1.8Hz,1H),6.99(d,J=2.1Hz,1H),6.87(d,J=8.1Hz,1H),6.83(s,2H),5. 72(t,J=10.3Hz,1H),5.38-5.29(m,3H),4.42(d,J=15.1Hz,1H),4.21(dt,J=10.4,6.0Hz,1H),4.17-4.01(m,2H), 3.94-3.85(m,7H),3.77-3.58(m,4H),2.47(s,6H),2.23(s,3H),2.12(t,J=2.3Hz,1H),0.82(s,9H),-0.03(s,6H).

[0128] 13 C NMR (100MHz, CDCl3): δ165.04,149.39,149.09,142.98,141.05,140.48,135.87,1 33.60,132.70,132.10,131.56,131.36,129.75,129.54,128.67,128.46,128.41, 128.32,127.99,127.94,121.74,112.08,111.12,80.14,72.41,67.61,64.28,56.02,56.00,54.41,51.24,44.80,33.24,25.91,22.90,21.00,18.32,-5.42,-5.55.

[0129] (9) Preparation of Compound 16

[0130] Compound 15 (7.67 mmol, 1.0 eq) was dissolved in anhydrous THF (32 mL), and TBAF (11.5 mmol, 1.5 eq, 1 M / THF) and AcOH (38.35 mmol, 5.0 eq) were added at 0°C and reacted at room temperature for 24 h. After the reaction was completed, EtOAc was extracted and dried over Na2SO4. After the organic phase was concentrated, the product was directly purified by column chromatography, and the polarity of the eluent was PE:EA=2:1. Yield: 5.25 g, 90%, the product was a white solid. Melting point: 60-62°C.

[0131] Compound 16:

[0132] HRMS(ESI)[M+H] + calcd.for C 40 H 45 N2O9S2,761.2561,found,761.2564.

[0133] 1 H NMR (400MHz, CDCl3): δ8.46(t,J=1.8Hz,1H),8.27(dt,J=7.9,1.4Hz,1H),7.98(dd,J=7.9,1.6Hz,1H),7.61(t,J=7.9Hz ,1H),7.34-7.27(m,3H),7.22-7.15(m,2H),7.04(dd,J=8.2,1.9Hz,1H),6.99(d,J=1.9Hz,1H),6.87(d,J=8.2Hz,1H),6 .84(s,2H),5.58-5.48(m,1H),5.36-5.28(m,3H),4.31(d,J=14.9Hz,1H),4.25-4.20(m,1H),4.15-4.03(m,2H),3.89(s ,3H),3.88(s,3H),3.86-3.74(m,2H),3.56(dd,J=12.0,5.4Hz,1H),3.48-3.38(m,2H),2.46(s,6H),2.24-2.20(s,4H).

[0134] 13 C NMR (100MHz, CDCl3): δ165.08,149.45,149.11,143.44,140.73,140.63,13 5.46,133.73,132.24,132.09,131.62,131.36,130.40,129.65,128.84,12 8.36,128.33,128.19,127.93,126.49,121.81,112.16,111.15,79.70,72. 94,67.75,62.97,56.06,56.03,55.20,51.63,44.33,32.51,22.88,21.04.

[0135] (10) Preparation of Compound 17

[0136] Compound 16 (5.0 mmol, 1.0 eq), compound 14 (5.5 mmol, 1.1 eq) and EDCI (7.5 mmol, 1.5 eq) were dissolved in anhydrous DCM (25 mL), and DMAP (0.5 mmol, 0.1 eq) was added at 0°C. The reaction was carried out at room temperature for 24 h. After the reaction was completed, DCM was extracted and dried over Na2SO4. After the organic phase was concentrated, the product was directly purified by column chromatography. The polarity of the eluent was PE:EA=2:1. Yield: 4.11 g, 82%, the product was a white solid.

[0137] Compound 14: Compound 17:

[0138] Melting point: 52-54℃.

[0139] HRMS(ESI)[M+H] + calcd.for calcd.for C 48 H 49 BrN3O 12 S2,1002.1936,found,1002.1928.

[0140] 1 H NMR (400MHz, CDCl3): δ8.48(t,J=1.8Hz,1H),8.37-8.24(m,2H),8.11(dd,J=8.4,1.8Hz,1H),8.02(dd,J=8.3,2.4Hz,2H),7.63(t,J=7.8Hz,1H ),7.32-7.17(m,5H),7.04(dd,J=8.1,2.0Hz,1H),7.00(d,J=2.0Hz,1H),6.88(d,J=8.1Hz,1H),6.82(s,2H),5.71-5.56(m,1H),5.46(ddd,J=1 1.0,8.5,4.6Hz,1H),5.34(s,2H),5.04-4.76(m,3H),4.46(dd,J=11.9,8.3Hz,1H),4.42-4.32(m,2H),4.17(d,J=14.9Hz,1H),4.08(dd,J=18. 5,2.5Hz,1H),3.97-3.90(m,1H),3.89(d,J=4.4Hz,6H),3.87-3.78(m,1 H),3.56(ddd,J=16.5,4.8,2.1Hz,1H),2.49(s,6H),2.25-2.15(m,4H).

[0141] 13C NMR (100MHz, CDCl3): δ164.91,163.89,150.58,149.39,149.07,143.26,140.45,140.4 2,135.43,134.11,133.70,133.21,132.55,132.31,132.17,131.63,131.32,130.86,1 29.60,128.75,128.30,128.11,127.92,125.29,125.12,121.69,112.10,111.14,79.16,73.25,67.61,64.52,55.99,55.97,52.04,51.97,44.85,42.20,32.65,22.77,20.94.

[0142] (11) Preparation of Compound 18

[0143] Compound 17 (4.7 mmol, 1.0 eq), tert-butyloxycarbonyl 6-aminocaproic acid (5.64 mmol, 1.2 eq) and K2CO3 (7.05 mmol, 1.5 eq) were dissolved in acetone (23.5 mL). The mixture was stirred overnight at room temperature. After the reaction was completed, the mixture was extracted with EtOAc and dried with Na2SO4. The organic phase was concentrated and the product was directly purified by column chromatography. The polarity of the eluent was PE:EA=3:2. Yield: 5.07 g, 93%. The product was a yellow solid. Melting point: 48-50°C.

[0144] Compound 18:

[0145] HRMS(ESI)[M]calcd.for C 59 H 68 N4O 16 S2,1152.4072,found,1152.4078.

[0146] 1H NMR(400MHz,CDCl3):δ8.46(t,J=1.8Hz,1H),8.26(dt,J=7.8,1.4Hz,1H),8.23(d,J=1.8Hz,1H),8.12-7.95(m,3H),7.61(t,J=7.8Hz,1H),7.29-7.22(m,3H),7.22-7.18(m,2H),7.03(dd,J=8.2,2.0Hz,1H),6.98(d,J=2.0Hz,1H),6.86(d,J=8.2Hz,1H),6.81(s,2H),5.66-5.58(m,1H),5.50-5.40(m,3H),5.33(s,2H),4.81(td,J=8.8,5.5Hz,1H),4.58(s,1H),4.45(dd,J=11.8,8.3Hz,1H),4.37-4.27(m,2H),4.15(d,J=14.9Hz,1H),4.05(dd,J=18.5,2.5Hz,1H),3.95-3.84(m,7H),3.80(ddd,J=16.6,8.5,1.5Hz,1H),3.55(ddd,J=16.6,4.7,2.0Hz,1H),3.09(q,J=6.5Hz,2H),2.47(s,6H),2.41(t,J=7.4Hz,2H),2.20(s,3H),2.17(t,J=2.4Hz,1H),1.70-1.61(m,2H),1.52-1.44(m,2H),1.39-1.30(m,2H).

[0147] 13 C NMR(100MHz,CDCl3):δ172.81,164.81,164.11,155.98,150.21,149.32,149.00,143.19,140.43,140.33,135.36,133.96,133.60,132.27,132.12,132.10,131.54,131.45,131.25,130.93,130.21,129.53,128.67,128.22,128.19,128.03,127.85,125.03,124.96,121.62,112.05,111.09,79.13,78.92,73.19,67.53,64.39,62.37,55.91,55.88,53.50,51.89,44.70,40.30,33.83,32.53,29.67,28.39,26.20,24.45,22.69,20.85.

[0148] (12) Preparation of monomer M10:

[0149] Compound 18 (4.39 mmol, 1.0 eq) was dissolved in anhydrous DCM (22 mL), and triethylsilane (43.9 mmol, 10.0 eq) and TFA (57.1 mmol, 13.0 eq) were added in sequence. The reaction mixture was allowed to react at room temperature for 4 hours, and the reaction mixture was concentrated after dilution with acetone. The crude product and HATU (8.72 mmol, 2.0 eq) were dissolved in DMF (878 mL), and after 30 minutes, N,N-diisopropylethylamine (21.95 mmol, 5.0 eq) was added. After 36 hours, the reaction mixture was concentrated, washed with 1N HCl, 0.5N NaOH, and saturated brine in sequence, extracted with EtOAc, and dried with Na2SO4. After concentrating the organic phase, the product (monomer M10) was directly purified by column chromatography, and the polarity of the eluent was PE:EA=1:1. Yield: 2.06 g, 53%, the product was a white solid. Melting point: 140-142°C.

[0150] Monomer M10:

[0151] HRMS(ESI)[M+H] + calcd.for C 45 H 49 N4O 11 S2,885.2834,found,885.2842.

[0152] 11H NMR (400 MHz, CDCl3): δ 8.43 (d, J = 1.5 Hz, 1H), 8.25 (dt, J = 7.8, 1.5 Hz, 1H), 8.17 - 8.09 (m, 3H), 7.92 (dt, J = 7.8, 1.5 Hz, 1H), 7.64 (t, J = 7.8 Hz, 1H), 7.37 - 7.30 (m, 3H), 7.30 - 7.26 (m, 1H), 7.19 (t, J = 5.9 Hz, 1H), 6.87 (s, 2H), 5.68 - 5.41 (m, 4H), 5.21 (td, J = 9.1, 5.5 Hz, 1H), 4.58 (dd, J = 11.9, 8.9 Hz, 1H), 4.45 (dd, J = 11.9, 5.6 Hz, 1H), 4.36 (d, J = 14.5 Hz, 1H), 4.25 (d, J = 14.5 Hz, 1H), 4.01 - 3.73 (m, 3H), 3.53 (dq, J = 13.2, 6.5 Hz, 1H), 3.49 - 3.41 (m, 1H), 3.19 (dq, J = 12.5, 6.1 Hz, 1H), 2.58 - 2.46 (m, 8H), 2.22 (s, 3H), 2.15 (t, J = 2.5 Hz, 1H), 1.71 (dq, J = 14.2, 7.1 Hz, 2H), 1.65 - 1.57 (m, 2H), 1.47 - 1.31 (m, 2H).

[0153] 13 13C NMR (100 MHz, CDCl3): δ 173.21, 165.32, 165.26, 150.02, 143.70, 140.84, 139.58, 132.83, 132.62, 132.34, 130.37, 130.31, 129.88, 129.72, 128.89, 128.65, 128.33, 125.12, 124.36, 124.12, 73.51, 64.87, 62.13, 53.24, 51.21, 45.44, 39.86, 33.63, 32.59, 28.69, 26.03, 24.13, 22.85, 21.07.

[0154] Example 4

[0155] Monomers M1-M7 (20-100eq) were added to a 10mL vial equipped with a stirrer, placed under a nitrogen atmosphere, and dissolved in deoxygenated THF at room temperature; Grubbs third generation (G3) initiator (1eq) solution was prepared in another 4mL vial; an appropriate volume of G3 solution was quickly added to the stirred reaction mixture containing the monomer solution using a microliter syringe to make the total monomer concentration 0.08M. After the specified time, the polymerization was terminated by adding an excess of ethyl vinyl ether (EVE), the reaction mixture was stirred for 1 minute, and then triethylamine (0.1mL) was added and the reaction mixture was concentrated in vacuo. The polymers were characterized by GPC and 1H NMR. The polymerization results of M1-M7 are shown in Table 1. The GPC curves of the polymerization results of M1-M2, M4-M7 are shown in Figures 1 to 6 shown.

[0156] The polymerization reaction equation of M1-M7:

[0157]

[0158] Table 1 Aggregation results of M1-M7

[0159]

[0160] [a] Calculated by H NMR spectroscopy; [b] Determined by GPC with THF as the mobile phase and polyacrylate as the standard. In the table, t represents the polymerization reaction time, and Conv. (%) represents the conversion rate.

[0161] Example 5

[0162] Monomers M8-M9 (25-100 eq) were added to a 10 mL vial equipped with a stirrer and placed under a nitrogen atmosphere. They were dissolved in deoxygenated THF at room temperature. A Grubbs third generation (G3-Cl) initiator (1 eq) solution was prepared in another 4 mL vial. An appropriate volume of G3-Cl solution was quickly added to the stirred reaction mixture containing the monomer solution using a microliter syringe to make the total monomer concentration 0.1 M. After the specified time, the polymerization was terminated by adding an excess of ethyl vinyl ether (EVE). The reaction mixture was stirred for 1 minute and the reaction mixture was concentrated in vacuo. GPC and 1 The polymers were characterized by H NMR.

[0163] The polymerization results of M8-M9 are shown in Table 2. The GPC curve of the polymerization results of M8-M9 is shown in Table 2. Figures 7-8 shown.

[0164] The polymerization reaction equation of M8-M9 is:

[0165]

[0166] Table 2 Aggregation results of M8-M9

[0167]

[0168] [a] Calculated by H NMR spectroscopy; [b] Determined by GPC with THF as the mobile phase and polyacrylate as the standard.

[0169] Example 6

[0170] Monomers M10-M15 (25-100eq) were added to a 10mL vial equipped with a stirrer and placed under a nitrogen atmosphere. They were dissolved in deoxygenated DCM at room temperature. A Grubbs third generation (G3) initiator (1eq) solution was prepared in another 4mL vial. An appropriate volume of G3 solution was quickly added to the stirred reaction mixture containing the monomer solution using a microliter syringe to make the total monomer concentration 0.1M. After a specified time, the polymerization was terminated by adding an excess of ethyl vinyl ether (EVE). The reaction mixture was stirred for 1 minute, then a certain volume of triethylamine (0.1mL) was added and the reaction mixture was concentrated in vacuo. The reaction mixture was analyzed by GPC and 1 The polymers were characterized by H NMR. The polymerization results of M10-M13 are shown in Tables 3, 4, and 5. The GPC curves of the polymerization results of M10-M13 are shown in Figures 9 to 12 The polymerization results of M14-M15 are shown in Table 6. The GPC curve of the polymerization results of M14-M15 is shown in Table 6. Figures 13-14 shown.

[0171] The polymerization reaction equation of M10-M11 is:

[0172]

[0173] Table 3: Polymerization results of M10-M11

[0174]

[0175] [a] Calculated by H-NMR spectroscopy; [b] Determined by GPC with CHCl3 as the mobile phase and polystyrene as the standard.

[0176] The polymerization reaction equation of M12 is:

[0177]

[0178] Table 4 Aggregation results of M12

[0179]

[0180] [a] Calculated by H NMR spectroscopy; [b] Determined by GPC with CHCl3 as the mobile phase and polystyrene as the standard. The polymerization reaction equation of M13 is:

[0181]

[0182] Table 5 Aggregation results of M13

[0183]

[0184] [a] Calculated by H NMR spectrum; [b] Determined by GPC with CHCl3 as the mobile phase and polystyrene as the standard. The polymerization reaction equation of M14-M15 is:

[0185]

[0186] Table 6 Aggregation results of M14-M15

[0187]

[0188] [a] Calculated by H-NMR spectroscopy; [b] Determined by GPC with CHCl3 as the mobile phase and polystyrene as the standard.

[0189] Example 7

[0190] Block copolymerization: Monomers MBn (20eq) and M1 (30eq) or monomers MBn (25eq) and M1 (40eq) were added to two different 5ml vials, placed under a nitrogen atmosphere, and dissolved in deoxygenated THF at room temperature. Prepare Grubbs third generation (G3) initiator (1eq) solution in another 4mL vial. Use a microliter syringe to quickly add an appropriate volume of G3 solution to the stirring solution containing MBn to a monomer concentration of 0.08M. After stirring the reaction mixture for 6 minutes, use a microliter syringe to quickly add the M1 solution to the reaction solution to a concentration of 0.08M, and then stir at room temperature. After 12 minutes or 15 minutes, add an excess of ethyl vinyl ether (EVE) to terminate the polymerization. Stir the reaction mixture for 1 minute, then add a certain volume of triethylamine (0.1mL), and concentrate the reaction mixture in vacuo. Use GPC and 1 The polymer was characterized by H NMR. The block polymerization results are shown in Table 7. The GPC curve of the block polymerization results is shown in Fig.15 shown.

[0191] Block polymerization reaction equation:

[0192]

[0193] Table 7 Block polymerization results

[0194]

[0195] [a] Calculated by H NMR spectroscopy; [b] Determined by GPC with THF as the mobile phase and polyacrylate as the standard.

[0196] Example 9

[0197] Random copolymerization: Monomers M1 and Mcarb (25 and 50 eq, respectively) were added together into a 10 mL vial equipped with a stirrer, placed under a nitrogen atmosphere, and dissolved in deoxygenated THF at room temperature. In another 4 mL vial, a Grubbs third generation (ligand is 3-chloropyridine) initiator (G3-Cl) solution was prepared. An appropriate volume of G3-Cl solution was quickly added to the stirring bottle containing the monomer solution using a microliter syringe to make a total monomer concentration of 0.1 M, and then stirred at 0°C. After the specified time, the polymerization was terminated by adding an excess of ethyl vinyl ether (EVE). The reaction mixture was stirred for 1 minute, then a certain volume of triethylamine (0.1 mL) was added, and the reaction mixture was concentrated in vacuo. Use GPC and 1 The random copolymerization results are shown in Table 8, and the GPC curves are shown in Fig.16 shown.

[0198] The reaction equation of copolymerization:

[0199]

[0200] Table 8 Random copolymerization results

[0201]

[0202] [a] Determined by GPC with THF as the mobile phase and polyacrylate as the standard.

[0203] Degradation test:

[0204] P1 and control group P Bn The block copolymers prepared in Example 8, P10, and random copolymers prepared in Example 9 were subjected to a photodegradation test under 365 nm ultraviolet light. The GPC degradation curves are shown in FIG. Figure 17-21 shown.

Claims

1. A method for preparing a photoresponsive degradable polymer, characterized in that: The following steps are involved: The monomer containing the photodegradable group is subjected to an ene-alkyne metathesis reaction to obtain a photoresponsive degradable polymer; The monomer containing the photodegradable group is a monomer without ring strain; The monomer containing the photodegradable group is R1, R2 are photodegradable groups; Or the monomer containing the photodegradable group is -R4-R3-, R5 is a group containing -NH-C(O)-, and R6 is O or -OC(O)-.

2. The method for preparing a photoresponsive degradable polymer according to claim 1, characterized in that: R1 is specifically R2 is specifically The -R4-R3 is specifically The phenylene group is substituted in the ortho, meta, or para position; R5 is -CH2-NH-C(O)-CH2-.

3. The method for preparing the photoresponsive degradable polymer according to claim 2, characterized in that: The monomer containing a photodegradable group is specifically one or more of the following structural compounds:

4. The method for preparing a photoresponsive degradable polymer according to claim 1, characterized in that: The catalyst for the olefin and alkyne metathesis reaction is a Grubbs third generation catalyst; The solvent of the reaction is THF or DCM; the reaction time is ≥5 min; The concentration of the monomer containing photodegradable groups in the solvent is 0.01-0.2M; the molar ratio of the catalyst used in the reaction to the monomer containing photodegradable groups is 1:(20-100).

5. The method for preparing a photoresponsive degradable polymer according to claim 4, characterized in that: The catalyst for the olefin and acetylene metathesis reaction is benzylidene-[1,3-bis(trimethylphenyl)-2-imidazolinylidene]-dichloro-bis(3-chloropyridine)ruthenium or benzylidene-[1,3-bis(trimethylphenyl)-2-imidazolinylidene]-dichloro-bispyridine ruthenium.

6. The method for preparing a photoresponsive degradable polymer according to claim 1, characterized in that: After the reaction is completed, ethyl vinyl ether is added to terminate the reaction, triethylamine is added or not, and the solvent is removed.

7. The method for preparing a photoresponsive degradable polymer according to claim 1, characterized in that: The monomer containing the photodegradable group is of formula I, and the general formula of the photoresponsive degradable polymer is The wavy line on the left connects the groups from the catalyst; The monomer containing the photodegradable group is of formula II, and the general formula of the photoresponsive degradable polymer is The wavy line on the left connects the groups from the catalyst; The monomer containing the photodegradable group is of formula III, and the general formula of the photoresponsive degradable polymer is The wavy line on the left connects the groups from the catalyst; The monomer containing the photodegradable group is of formula IV, and the general formula of the photoresponsive degradable polymer is The wavy line on the left connects the groups from the catalyst.

8. The method for preparing a photoresponsive degradable polymer according to claim 1, characterized in that: Alternatively, a monomer containing a photodegradable group is reacted with an ene-yne ​​monomer without a photoresponsive segment through block copolymerization or random copolymerization to obtain a photoresponsive degradable polymer.

9. The method for preparing a photoresponsive degradable polymer according to claim 8, characterized in that: When the monomer containing the photodegradable group is When the reaction is carried out by block copolymerization or random copolymerization; The block copolymerization refers to reacting ene and acetylene monomers without photoresponsive fragments under a protective atmosphere under the action of a catalyst, and then adding monomers containing photodegradable groups to carry out copolymerization to obtain photoresponsive degradable polymers; The random copolymerization refers to mixing a monomer containing a photodegradable group with an ene-yne ​​monomer without a photoresponsive segment under a protective atmosphere, and copolymerizing them under the action of a catalyst to obtain a photoresponsive degradable polymer; The ene-yne ​​monomer without a photoresponsive segment is 10. A photoresponsive degradable polymer obtained by the preparation method according to any one of claims 1 to 9.

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