A KI / PPh 3 Promoted decarboxylative cyclization of 1,6-enynes with N-hydroxyphthalimide esters

Abstract

The present invention relates to a KI / PPh3-promoted decarboxylation cyclization method of 1,6-enyne and N-hydroxyphthalimide ester. The method is carried out by adding 1,6-enyne compounds, N-hydroxyphthalimide ester, KI / PPh3 and solvent into a Schlenk reaction bottle, filling with nitrogen and stirring the reaction under 5W blue light (456nm) irradiation conditions to achieve an efficient decarboxylation cyclization reaction.

Description

Technical Field

[0001] The present application belongs to the field of organic synthesis, and specifically relates to a KI / PPh3-promoted decarboxylation cyclization method of 1,6-enyne and N-hydroxyphthalimide ester. Background Art

[0002] Carboxylic acids are a class of stable, cheap and readily available raw materials. They are one of the most suitable and basic synthetic platforms in the construction of complex molecular frameworks. Therefore, generating free radicals through decarboxylation has become one of the powerful strategies to achieve cyclization. Generally speaking, N-hydroxyphthalimide esters, as donors of alkyl radicals, can be decarboxylated to generate free radicals with the help of the following systems: (1) heating conditions, (2) electrocatalysis, (3) visible light catalysis, etc. However, decarboxylation under thermal conditions requires transition metal catalysts and bases, and electrochemical decarboxylation still requires dangerous and explosive electrosynthetic additives. Visible light catalysis has become an ideal decarboxylation condition that has attracted much attention due to its renewable, mild, and unique activation mode.

[0003] The free radical cyclization reaction of 1,n-enynes is an important way to quickly prepare cyclic compounds, especially complex cyclic compounds. At present, people have developed a series of methods for the cyclization of 1,n-enynes with free radicals. However, most of the existing strategies require harsh conditions, usually using oxidants as free radical initiators and transition metals as catalysts to achieve the cyclization reaction of 1,n-enynes. Based on the inventors' continued research interest in green and sustainable chemistry, in the present invention, we propose a method for the photocatalytic decarboxylation cyclization reaction of 1,6-enynes with N-hydroxyphthalimide esters using cheap and readily available KI / PPh3 as a photocatalyst. Summary of the invention

[0004] The present invention aims to overcome the deficiencies of the prior art and to provide a KI / PPh3-promoted decarboxylation cyclization method for 1,6-enyne and N-hydroxyphthalimide ester, which can prepare the target product in a high yield under mild conditions.

[0005] The present invention provides a KI / PPh3-promoted decarboxylation cyclization method of 1,6-enyne and N-hydroxyphthalimide ester, comprising the following steps:

[0006] Add the 1,6-eneyne compound of Formula 1, the N-hydroxyphthalimide ester of Formula 2, an iodine source, a ligand and a solvent into a Schlenk reaction flask, fill the reaction flask with nitrogen and stir the reaction under 5W blue light (456nm) irradiation conditions, monitor the reaction progress by TLC or GC until the raw materials react completely, and obtain a decarboxylation cyclization product (I) by post-treatment;

[0007] The structure of the 1,6-enyne compound shown in Formula 1, the N-hydroxyphthalimide ester shown in Formula 2 and the target product shown in Formula I is as shown in the following formula (see Formula 1):

[0008]

[0009] In the compounds represented by Formula 1, Formula 2, and Formula I, R 1 Selected from C1-C 10 Alkyl, substituted or unsubstituted C6-C 20 Aryl;

[0010] R 2 Selected from hydrogen, C1-C 10 Alkyl, substituted or unsubstituted C6-C 20 Aryl;

[0011] R 3 Selected from C1-C 10 Alkyl, C6-C 20 Aryl;

[0012] R 4 Selected from C1-C 10 Alkyl, C6-C 20 Aryl.

[0013] wherein the substituents in the substituted or unsubstituted are selected from halogen, C1-C 10 Alkyl, C1-C 10 Halogenated alkyl, C1-C 10 Alkoxy, nitro, cyano.

[0014] Preferably, R 1 Selected from C1-C 10 Alkyl, substituted or unsubstituted C6-C 20 Aryl;

[0015] R 2 Selected from hydrogen, C1-C 10 Alkyl, substituted or unsubstituted C6-C 20 Aryl;

[0016] R 3 Selected from C1-C 10 Alkyl, C6-C 20 Aryl;

[0017] R 4 Selected from C1-C 10 Alkyl, C6-C 20 Aryl.

[0018] wherein the substituents in the substituted or unsubstituted are selected from halogen, C1-C 10 Alkyl, C1-C 10Halogenated alkyl, C1-C 10 Alkoxy, nitro or cyano.

[0019] Preferably, the iodine source is selected from potassium iodide, sodium iodide, tetrabutylammonium iodide or ammonium iodide.

[0020] Preferably, the ligand is selected from triphenylphosphine, tricyclohexylphosphine, tri(4-methoxyphenyl)phosphine or tri(4-fluorophenyl)phosphine.

[0021] Preferably, the amount of potassium iodide is 1.0-2.0 equivalents.

[0022] Preferably, the triphenylphosphine is used in an amount of 10-30 mol%.

[0023] Preferably, the blue light power is 2W-45W.

[0024] Preferably, the solvent is N,N-dimethylformamide, dimethyl sulfoxide, acetonitrile, acetone, tetrahydrofuran or ethanol.

[0025] Preferably, the post-treatment operation is as follows: the reaction solution after the reaction is completed is extracted with ethyl acetate, the organic phase is dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to remove the solvent, and the residue is separated by column chromatography, the elution solvent is: ethyl acetate / n-hexane, to obtain a decarboxylation cyclization product (I).

[0026] Preferably, the iodine source is potassium iodide, the ligand is triphenylphosphine, the amount of potassium iodide is 1.5 equivalents, the amount of triphenylphosphine is 20 mol%, the blue light power is 5 W, and the solvent is N, N-dimethylformamide. The beneficial effect of the present invention is: a KI / PPh3-promoted decarboxylation cyclization method of 1,6-enyne and N-hydroxyphthalimide ester is proposed. The method has the advantages of a wide range of reaction substrates, simplicity and high efficiency, and is particularly suitable for industrial production. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below in conjunction with specific embodiments, but the present invention is not limited thereto.

[0028] The experimental methods described in the following examples are conventional methods unless otherwise specified; the reagents and raw materials can be obtained from commercial sources and / or prepared according to known methods unless otherwise specified.

[0029] Examples 1-7 are experiments for optimizing reaction conditions.

[0030] Example 1

[0031]

[0032] A 1,6-enyne compound (39.8 mg, 0.2 mmol) of formula 1a, N-hydroxyphthalimide ester (109.2 mg, 0.4 mmol) of formula 2a, potassium iodide (49.5 mg, 1.5 eq), triphenylphosphine (PPh3, 10.5 mg, 20 mol%), and N,N-dimethylformamide (2.0 mL) were added to a Schlenk bottle, and then nitrogen was filled into the reaction bottle and stirred under 5 W blue light (456 nm) irradiation conditions. The reaction progress was monitored by TLC until the raw material disappeared (reaction time was 18 hours). After the reaction was completed, the reaction solution was extracted with ethyl acetate, the organic phase was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to remove the solvent, and the residue was separated by column chromatography (elution solvent: ethyl acetate / n-hexane) to obtain the target product I-1 (83% yield); 1 HNMR(400MHz, CDCl3)δ:7.70-7.68(m,2H),7.41-7.37(m,2H),7.18-7.14(m,1H),5.23(t, J=2.4Hz,1H),5.09(t,J=2.8Hz,1H),4.47-4.43(m,2H),1.86-1.81(m,1H ),1.61-1.52(m,8H),1.30(s,3H),1.12-1.07(m,2H),0.95-0.88(m,2H); 13 C NMR (101MHz, CDCl3) δ: 177.6, 146.0, 139.2, 129.0, 124.6, 119.9, 107.9, 52.0, 49.3, 46.6, 35.1, 34.7, 33.6, 26.9, 26.4, 26.3, 26.2; HRMS m / z(ESI)calcd for C 19 H 26 NO([M+H] + )284.2009,found 284.2004.

[0033] Example 2

[0034] The amount of the free radical precursor N-hydroxyphthalimide ester used was 1.0 equivalent (54.6 mg), and the other conditions were the same as in Example 1. The yield of the target product I-1 was 75%.

[0035] Example 3

[0036] The amount of iodine source potassium iodide used was 1.0 equivalent (33.0 mg), and the other conditions were the same as in Example 1. The yield of the target product I-1 was 76%.

[0037] Example 4

[0038] The amount of the ligand triphenylphosphine used was 10 mol% (5.3 mg), and the other conditions were the same as in Example 1. The yield of the target product I-1 was 74%.

[0039] Example 5

[0040] The iodine source tetrabutylammonium iodide replaced potassium iodide, and the other conditions were the same as in Example 1. The yield of the target product I-1 was 68%.

[0041] Example 6

[0042] The ligand tricyclohexylphosphine replaced triphenylphosphine, and the other conditions were the same as in Example 1. The yield of the target product I-1 was 72%.

[0043] Example 7

[0044] The solvent dimethyl sulfoxide replaced N,N-dimethylformamide, and the other conditions were the same as in Example 1, and the yield of the target product I-1 was 50%.

[0045] It can be seen from the above examples 1-7 that the best reaction conditions are the reaction conditions of Example 1, i.e., iodine source potassium iodide (1.5 eq), ligand triphenylphosphine (20 mol%), free radical precursor N-hydroxyphthalimide ester (2.0 eq), in a nitrogen atmosphere and irradiated with 5W blue light (456 nm). On the basis of obtaining the best reaction conditions, the inventors further selected 1,6-eneyne compounds with different substituents and N-hydroxyphthalimide ester compounds as raw materials under the best reaction conditions to develop an efficient decarboxylation cyclization reaction method.

[0046] Example 8

[0047]

[0048] A 1,6-enyne compound (39.8 mg, 0.2 mmol) of formula 1a, N-hydroxyphthalimide ester (103.6 mg, 0.4 mmol) of formula 2b, potassium iodide (49.5 mg, 1.5 eq), triphenylphosphine (PPh3, 10.5 mg, 20 mol%), and N,N-dimethylformamide (2.0 mL) were added to a Schlenk bottle, and then nitrogen was filled into the reaction bottle and stirred under 5 W blue light (456 nm) irradiation conditions. The reaction progress was monitored by TLC until the raw material disappeared (reaction time was 18 hours). After the reaction was completed, the reaction solution was extracted with ethyl acetate, the organic phase was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to remove the solvent, and the residue was separated by column chromatography (elution solvent: ethyl acetate / n-hexane) to obtain the target product I-2 (80% yield); 1HNMR(400MHz, CDCl3)δ:7.73-7.70(m,2H),7.41-7.37(m,2H),7.18-7.14(m,1H),5.24(t, J=2.0Hz,1H),5.11(t,J=2.8Hz,1H),4.46-4.44(m,2H),1.97-1.92(m,1H),1.73-1 .68(m,3H),1.57-1.52(m,3H),1.43-1.39(m,2H),1.32(s,3H),1.14-1.08(m,2H); 13 C NMR(101MHz, CDCl3)δ:177.6,146.1,139.2,129.0,124.5,119.8,108.0,52.1,49.9,46.0,37.1,34.4,32.8,26.3, 25.3,24.8; HRMS m / z(ESI)calcd for C 18 H 24 NO([M+H] + )270.1852,found270.1858.

[0049] Example 9

[0050]

[0051] Add the 1,6-enyne compound (39.8 mg, 0.2 mmol) of formula 1a, N-hydroxyphthalimide ester (130.0 mg, 0.4 mmol) of formula 2c, potassium iodide (49.5 mg, 1.5 eq), triphenylphosphine (PPh3, 10.5 mg, 20 mol%), N,N-dimethylformamide (2.0 mL) into a Schlenk bottle, then fill the reaction bottle with nitrogen and stir the reaction under 5 W blue light (456 nm) irradiation conditions, monitor the reaction progress by TLC until the raw material disappears (reaction time is 18 hours), after the reaction is completed, extract the reaction solution with ethyl acetate, dry the organic phase with anhydrous sodium sulfate, filter and concentrate under reduced pressure to remove the solvent, separate the residue by column chromatography (elution solvent: ethyl acetate / n-hexane) to obtain the target product I-3 (0.0402 g, 60% yield); 1H NMR(400MHz, CDCl3)δ:7.71-7.69(m,2H),7.42-7.38(m,2H),7.19-7.15 (m,1H),5.20(t,J=2.4Hz,1H),5.16(t,J=2.8Hz,1H),4.55-4.52(m,2H),1.91(d,J= 14.4Hz,1H),1.86-1.83(m,3H),1.63-1.53(m,10H),1.46-1.42(m,3H),1.29(s,3H); 13 C NMR(101 MHz, CDCl3)δ:177.8,146.2,139.2,129.0,124.6,120.1,108.7,53.9,52.0,47.9,43.8,36.9,34.2, 30.5,28.7; HRMS m / z(ESI)calcd for C 23 H 30 NO([M+H] + )336.2322, found 336.2316.

[0052] Example 10

[0053]

[0054] A 1,6-enyne compound (39.8 mg, 0.2 mmol) of formula 1a, N-hydroxyphthalimide ester (98.8 mg, 0.4 mmol) of formula 2d, potassium iodide (49.5 mg, 1.5 eq), triphenylphosphine (PPh3, 10.5 mg, 20 mol%), and N,N-dimethylformamide (2.0 mL) were added to a Schlenk bottle. Then, nitrogen was filled into the reaction bottle and stirred under 5 W blue light (456 nm) irradiation conditions. The reaction progress was monitored by TLC until the raw material disappeared (reaction time was 18 hours). After the reaction was completed, the reaction solution was extracted with ethyl acetate, the organic phase was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to remove the solvent, and the residue was separated by column chromatography (elution solvent: ethyl acetate / n-hexane) to obtain the target product I-4 (87% yield); 1HNMR(500MHz, CDCl3)δ:7.73-7.71(m,2H),7.41-7.37(m,2H),7.18-7.15(m,1H),5.24(t, J=2.5Hz,1H),5.17(t,J=2.5Hz,1H),4.52-4.51(m,2H),2.06(d,J=14.5Hz,1H),1.64(d,J=14.5Hz,1H),1.31(s,3H),0.90(s,9H); 13 C NMR(126MHz, CDCl3)δ:177.5,145.9,139.2,129.0,124.5,119.8,108.9,52.6,51.9,48.7,32.0,31.2,30.1; HRMS m / z(ESI)calcd forC 17 H 24 NO([M+H] + )258.1852, found 258.1846.

[0055] Embodiment 11

[0056]

[0057] A 1,6-enyne compound (39.8 mg, 0.2 mmol) of formula 1a, N-hydroxyphthalimide ester (104.4 mg, 0.4 mmol) of formula 2e, potassium iodide (49.5 mg, 1.5 eq), triphenylphosphine (PPh3, 10.5 mg, 20 mol%), and N,N-dimethylformamide (2.0 mL) were added to a Schlenk bottle, and then nitrogen was filled into the reaction bottle and stirred under 5 W blue light (456 nm) irradiation conditions. The reaction progress was monitored by TLC until the raw material disappeared (reaction time was 18 hours). After the reaction was completed, the reaction solution was extracted with ethyl acetate, the organic phase was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to remove the solvent, and the residue was separated by column chromatography (elution solvent: ethyl acetate / n-hexane) to obtain the target product I-5 (81% yield); 1HNMR(400MHz, CDCl3)δ:7.72-7.70(m,2H),7.41-7.37(m,2H),7.18-7.14(m,1H),5.22(t, J=2.4Hz,1H),5.17(t,J=2.4Hz,1H),4.52-4.49(m,2H),2.01(d,J=14.4Hz,1H),1.64(d,J= 14.4Hz,1H),1.31(s,3H),1.23-1.18(m,2H),0.84(s,3H),0.82(d,J=2.8Hz,3H),0.78(d,J =7.6Hz,3H); 13 C NMR(101MHz, CDCl3)δ:177.7,146.0,139.2,129.0,124.6,119.9,108.8, 51.9,50.2,48.6,36.5,34.4,30.2,27.9,27.6,8.4; HRMS m / z(ESI)calcd forC 18 H 26 NO([M+H] + ) 272.2009, found 272.2001.

[0058] Example 12

[0059]

[0060] Add the 1,6-enyne compound (39.8 mg, 0.2 mmol) of formula 1a, N-hydroxyphthalimide ester (118.0 mg, 0.4 mmol) of formula 2f, potassium iodide (49.5 mg, 1.5 eq), triphenylphosphine (PPh3, 10.5 mg, 20 mol%), N,N-dimethylformamide (2.0 mL) into a Schlenk bottle, then fill the reaction bottle with nitrogen and stir the reaction under 5 W blue light (456 nm) irradiation conditions, monitor the reaction progress by TLC until the raw material disappears (reaction time is 18 hours), after the reaction is completed, extract the reaction solution with ethyl acetate, dry the organic phase with anhydrous sodium sulfate, filter and concentrate under reduced pressure to remove the solvent, separate the residue by column chromatography (elution solvent: ethyl acetate / n-hexane) to obtain the target product I-6 (84% yield); 1HNMR(500MHz, CDCl3)δ:7.71-7.68(m,2H),7.39-7.36(m,2H),7.26-7.25(m,2H), 7.17-7.12(m,4H),5.21(t,J=2.5Hz,1H),5.05(t,J=2.5Hz,1H),4.41-4.39(m,2H),2. 62-2.59(m,1H),2.56-2.51(m,1H),1.92-1.88(m,1H),1.60-1.57(m,3H),1.31(s,3H); 13 C NMR (126MHz, CDCl3) δ: 177.2, 145.8, 142.0, 139.0, 128.9, 128.4, 128.3, 125.8, 124.6, 119.8, 107.8, 52.0, 49.9, 39.3, 36.1, 26.6, 24.8; HRMS m / z(ESI)calcd for C 21 H 24 NO([M+H] + )306.1852, found 306.1856.

[0061] Embodiment 13

[0062]

[0063] Add the 1,6-enyne compound (39.8 mg, 0.2 mmol) of formula 1a, N-hydroxyphthalimide ester (149.6 mg, 0.4 mmol) of formula 2g, potassium iodide (49.5 mg, 1.5 eq), triphenylphosphine (PPh3, 10.5 mg, 20 mol%), N,N-dimethylformamide (2.0 mL) into a Schlenk bottle, then fill the reaction bottle with nitrogen and stir the reaction under 5 W blue light (456 nm) irradiation conditions, monitor the reaction progress by TLC until the raw material disappears (reaction time is 18 hours), after the reaction is completed, extract the reaction solution with ethyl acetate, dry the organic phase with anhydrous sodium sulfate, filter and concentrate under reduced pressure to remove the solvent, separate the residue by column chromatography (elution solvent: ethyl acetate / n-hexane) to obtain the target product I-7 (70% yield); 1HNMR(400MHz, CDCl3)δ:7.71-7.68(m,2H),7.42-7.38(m,2H),7.19-7.15(m,1H),5.26(t, J=2.0Hz,1H),5.12(t,J=2.4Hz,1H),4.53-4.41(m,2H),4.04-3.86(m,2H),2.6 5-2.54(m,2H),1.92-1.86(m,1H),1.60-1.50(m,6H),1.42(s,9H),1.32(s,3H); 13 C NMR (101MHz, CDCl3) δ: 177.2, 154.8, 145.6, 139.0, 129.0, 124.8, 119.9, 108.2, 79.2, 51.8, 49.1, 45.3, 33.7, 33.1, 32.5, 29.7, 28.4; HRMS m / z(ESI)calcd for C 23 H 33 N2O3([M+H] + )385.2486, found 345.2488.

[0064] Embodiment 14

[0065]

[0066] Add the 1,6-enyne compound (45.8 mg, 0.2 mmol) of formula 1b, N-hydroxyphthalimide ester (98.8 mg, 0.4 mmol) of formula 2d, potassium iodide (49.5 mg, 1.5 eq), triphenylphosphine (PPh3, 10.5 mg, 20 mol%), N,N-dimethylformamide (2.0 mL) into a Schlenk bottle, then fill the reaction bottle with nitrogen and stir the reaction under 5 W blue light (456 nm) irradiation conditions, monitor the reaction progress by TLC until the raw material disappears (reaction time is 18 hours), after the reaction is completed, extract the reaction solution with ethyl acetate, dry the organic phase with anhydrous sodium sulfate, filter and concentrate under reduced pressure to remove the solvent, separate the residue by column chromatography (elution solvent: ethyl acetate / n-hexane) to obtain the target product I-8 (88% yield); 1HNMR(400MHz, CDCl3)δ:7.61-7.59(m,2H),6.93-6.91(m,2H),5.22(t,J=2.4Hz,1H), 5.16(t,J=2.4Hz,1H),4.47(t,J=2.4Hz,2H),3.80(s,3H),2.05(d,J=14.4Hz,1H),1.62(d,J=14.4Hz,1H),1.30(s,3H),0.89(s,9H); 13 C NMR(101MHz, CDCl3)δ:177.1,156.6,146.1,132.4,121.6,114.2,108.8,55.5,52.6,52.3,48.5,32.0,31.2,30.1; HRMS m / z(ESI)calcdfor C 18 H 26 NO([M+H] + )288.1958, found 288.1952.

[0067] Embodiment 15

[0068]

[0069] A 1,6-enyne compound (42.6 mg, 0.2 mmol) of formula 1c, N-hydroxyphthalimide ester (98.8 mg, 0.4 mmol) of formula 2d, potassium iodide (49.5 mg, 1.5 eq), triphenylphosphine (PPh3, 10.5 mg, 20 mol%), and N,N-dimethylformamide (2.0 mL) were added to a Schlenk bottle, and then nitrogen was filled into the reaction bottle and stirred under 5 W blue light (456 nm) irradiation conditions to react. The reaction progress was monitored by TLC until the raw material disappeared (reaction time was 18 hours). After the reaction was completed, the reaction solution was extracted with ethyl acetate, the organic phase was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to remove the solvent, and the residue was separated by column chromatography (elution solvent: ethyl acetate / n-hexane) to obtain the target product I-9 (90% yield); 1 HNMR(400MHz, CDCl3)δ:7.60-7.57(m,2H),7.20-7.17(m,2H),5.23-5.21(m,1H), 5.16-5.14(m,1H),4.50-4.48(m,2H),2.33(s,3H),2.07-2.02(m,1H),1.71-1.68(m,1H),1.30(s,3H),0.89(s,9H); 13C NMR(101MHz, CDCl3)δ:177.3,146.1,136.7,134.2,129.5,119.9,108.8,52.6,52.0,48.6,32.0,31.2,30.1,20.9; HRMS m / z(ESI)calcd for C 18 H 26 NO([M+H] + )272.2009, found 272.2003.

[0070] Example 16

[0071]

[0072] A 1,6-enyne compound (46.6 mg, 0.2 mmol) of formula 1d, N-hydroxyphthalimide ester (98.8 mg, 0.4 mmol) of formula 2d, potassium iodide (49.5 mg, 1.5 eq), triphenylphosphine (PPh3, 10.5 mg, 20 mol%), and N,N-dimethylformamide (2.0 mL) were added to a Schlenk bottle. Then, nitrogen was filled into the reaction bottle and stirred under 5 W blue light (456 nm) irradiation conditions. The reaction progress was monitored by TLC until the starting material disappeared (reaction time was 18 hours). After the reaction was completed, the reaction solution was extracted with ethyl acetate, the organic phase was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to remove the solvent, and the residue was separated by column chromatography (elution solvent: ethyl acetate / n-hexane) to obtain the target product I-10 (85% yield); 1 H NMR(400MHz, CDCl3)δ:7.70-7.66(m,2H),7.35-7.33(m,2H),5.25(t,J=2.4Hz, 1H), 5.18 (t, J = 2.8Hz, 1H), 4.48 (t, J = 2.4Hz, 2H), 2.05 (d, J = 14.4Hz, 1H), 1.64 (d, J = 14.4Hz, 1H), 1.31 (s, 3H), 0.88 (s, 9H); 13 C NMR(101MHz, CDCl3)δ:177.7,145.4,137.7,129.6, 129.0,120.8,109.2,52.6,51.8,48.7,32.0,31.2,30.0; HRMS m / z(ESI)calcd forC 17 H 23 ClNO ([M+H] + )292.1463, found 292.1467.

[0073] Embodiment 17

[0074]

[0075] A 1,6-enyne compound (53.4 mg, 0.2 mmol) of formula 1e, N-hydroxyphthalimide ester (98.8 mg, 0.4 mmol) of formula 2d, potassium iodide (49.5 mg, 1.5 eq), triphenylphosphine (PPh3, 10.5 mg, 20 mol%), and N,N-dimethylformamide (2.0 mL) were added to a Schlenk flask. Then, nitrogen was filled into the reaction flask and stirred under 5 W blue light (456 nm) irradiation conditions. The reaction progress was monitored by TLC until the starting material disappeared (reaction time was 18 hours). After the reaction was completed, the reaction solution was extracted with ethyl acetate, the organic phase was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to remove the solvent, and the residue was separated by column chromatography (elution solvent: ethyl acetate / n-hexane) to obtain the target product I-11 (75% yield); 1 H NMR(500MHz, CDCl3)δ:7.90-7.87(m,2H),7.65-7.63(m,2H),5.28(t,J=2.5Hz, 1H), 5.20 (t, J = 2.5Hz, 1H), 4.54 (t, J = 2.5Hz, 2H), 2.06 (d, J = 14.0Hz, 1H), 1.67 (d, J = 14.5Hz, 1H), 1.33 (s, 3H), 0.88 (s, 9H); 13 C NMR(126MHz, CDCl3)δ:178.3,145.0,142.0,126.1(q, J C-F =3.6Hz),126.0(q,J C-F =32.6Hz),123.0,119.1,109.4,52.7,51.6,48.8,32.0,31.2,30.0; 19 F NMR(471MHz, CDCl3)δ:-62.1; HRMS m / z(ESI)calcd for C 18 H 23 F3NO([M+H] + ) 326.1726, found 326.1722.

[0076] Embodiment 18

[0077]

[0078] A 1,6-enyne compound (44.8 mg, 0.2 mmol) of formula 1f, N-hydroxyphthalimide ester (98.8 mg, 0.4 mmol) of formula 2d, potassium iodide (49.5 mg, 1.5 eq), triphenylphosphine (PPh3, 10.5 mg, 20 mol%), and N,N-dimethylformamide (2.0 mL) were added to a Schlenk bottle, and then nitrogen was filled into the reaction bottle and stirred under 5 W blue light (456 nm) irradiation conditions. The reaction progress was monitored by TLC until the starting material disappeared (reaction time was 18 hours). After the reaction was completed, the reaction solution was extracted with ethyl acetate, the organic phase was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to remove the solvent, and the residue was separated by column chromatography (elution solvent: ethyl acetate / n-hexane) to obtain the target product I-12 (70% yield); 1 H NMR(500MHz, CDCl3)δ:7.90-7.89(m,2H),7.68-7.67(m,2H),5.29(t,J=2.5Hz,1H),5.22(t,J=2.5Hz, 1H), 4.53 (t, J = 2.5Hz, 2H), 2.05 (d, J = 14.5Hz, 1H), 1.67 (d, J = 14.5Hz, 1H), 1.33 (s, 3H), 0.88 (s, 9H); 13 C NMR(126MHz, CDCl3)δ:178.5,144.6,142.8,133.1,119.3, 118.8,109.7,107.3,52.7,51.5,48.9,32.0,31.2,30.0; HRMS m / z(ESI)calcd forC 18 H 23 N2O ([M+H] + )283.1805, found 283.1801.

[0079] Embodiment 19

[0080]

[0081] A 1,6-enyne compound (42.6 mg, 0.2 mmol) of formula 1g, N-hydroxyphthalimide ester (98.8 mg, 0.4 mmol) of formula 2d, potassium iodide (49.5 mg, 1.5 eq), triphenylphosphine (PPh3, 10.5 mg, 20 mol%), and N,N-dimethylformamide (2.0 mL) were added to a Schlenk flask. Then, nitrogen was filled into the reaction flask and stirred under 5 W blue light (456 nm) irradiation conditions to react. The reaction progress was monitored by TLC until the starting material disappeared (reaction time was 18 hours). After the reaction was completed, the reaction solution was extracted with ethyl acetate, the organic phase was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to remove the solvent, and the residue was separated by column chromatography (elution solvent: ethyl acetate / n-hexane) to obtain the target product I-13 (89% yield); 1 H NMR (400MHz, CDCl3) δ: 7.57 (s, 1H), 7.49-7.47 (m, 1H), 7.26 (t, J = 4.0Hz, 1H), 6.99-6.97(m,1H),5.23(t,J=2.4Hz,1H),5.16(t,J=2.8Hz,1H),4.51-4.50(m,2H),2 .38(s,3H),2.05(d,J=14.4Hz,1H),1.63(d,J=14.0Hz,1H),1.30(s,3H),0.90(s,9H); 13 C NMR(101MHz, CDCl3)δ:177.6,146.0,139.1,138.8,128.8,125.4,120.6,116.9,108.8,52.5,52.1, 48.7,32.0,31.2,30.1,21.7; HRMS m / z(ESI)calcd for C 18 H 26 NO([M+H] + )272.2009,found 272.2003.

[0082] Embodiment 20

[0083]

[0084] A 1,6-enyne compound (45.4 mg, 0.2 mmol) of formula 1h, N-hydroxyphthalimide ester (98.8 mg, 0.4 mmol) of formula 2d, potassium iodide (49.5 mg, 1.5 eq), triphenylphosphine (PPh3, 10.5 mg, 20 mol%), and N,N-dimethylformamide (2.0 mL) were added to a Schlenk flask. Then, nitrogen was filled into the reaction flask and stirred under 5 W blue light (456 nm) irradiation conditions. The reaction progress was monitored by TLC until the starting material disappeared (reaction time was 18 hours). After the reaction was completed, the reaction solution was extracted with ethyl acetate, the organic phase was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to remove the solvent, and the residue was separated by column chromatography (elution solvent: ethyl acetate / n-hexane) to obtain the target product I-14 (83% yield); 1 H NMR (500MHz, CDCl3) δ: 7.53 (d, J=2.5Hz, 1H), 7.40-7.38 (m, 1H), 7.13 (d, J= 8.0Hz,1H),5.21(t,J=2.5Hz,1H),5.15(t,J=2.5Hz,1H),4.49-4.48(m,2H),2.28(s,3H), 2.24(s,3H),2.05(d,J=14.5Hz,1H),1.62(d,J=14.5Hz,1H),1.30(s,3H),0.89(s,9H); 13 C NMR (126MHz, CDCl3) δ: 177.3, 146.5, 137.2, 137.0, 133.0, 130.0, 121.3, 117.4, 108.7, 52.6, 52.1, 48.6, 32.0, 31.2, 30.1, 20.1, 19.2; HRMS m / z(ESI)calcd for C 19 H 28 NO([M+H] + )286.2165, found 286.2169.

[0085] Embodiment 21

[0086]

[0087] A 1,6-enyne compound (55.0 mg, 0.2 mmol) of formula 1i, N-hydroxyphthalimide ester (98.8 mg, 0.4 mmol) of formula 2d, potassium iodide (49.5 mg, 1.5 eq), triphenylphosphine (PPh3, 10.5 mg, 20 mol%), and N,N-dimethylformamide (2.0 mL) were added to a Schlenk bottle. Then, nitrogen was filled into the reaction bottle and stirred under 5 W blue light (456 nm) irradiation conditions. The reaction progress was monitored by TLC until the raw material disappeared (reaction time was 18 hours). After the reaction was completed, the reaction solution was extracted with ethyl acetate, the organic phase was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to remove the solvent, and the residue was separated by column chromatography (elution solvent: ethyl acetate / n-hexane) to obtain the target product I-15 (81% yield, Z / E>20:1); 1 H NMR(500MHz, CDCl3)δ:7.76-7.74(m,2H),7.42-7.36(m,6H),7.30-7.27(m,1H),7.19-7.15(m,1H),6.66(s,1H), 4.68-4.65(m,1H),4.58-4.55(m,1H),2.01(d,J=14.5Hz,1H),1.85(d,J=14.5Hz,1H),1.26(s,3H),0.94(s,9H); 13 C NMR (126MHz, CDCl3) δ: 177.9, 139.1, 138.4, 136.6, 129.0, 128.9, 128.2, 127.2, 126.5, 124.7, 119.8, 54.1, 52.8, 49.1, 32.0, 30.8, 27.4; HRMS m / z(ESI)calcd for C 23 H 28 NO([M+H] + )334.2165,found334.2161.

[0088] Embodiment 22

[0089]

[0090] A 1,6-enyne compound (55.0 mg, 0.2 mmol) of formula 1j, N-hydroxyphthalimide ester (98.8 mg, 0.4 mmol) of formula 2d, potassium iodide (49.5 mg, 1.5 eq), triphenylphosphine (PPh3, 10.5 mg, 20 mol%), and N,N-dimethylformamide (2.0 mL) were added to a Schlenk bottle. Then, nitrogen was filled into the reaction bottle and stirred under 5 W blue light (456 nm) irradiation conditions. The reaction progress was monitored by TLC until the starting material disappeared (reaction time was 18 hours). After the reaction was completed, the reaction solution was extracted with ethyl acetate, the organic phase was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to remove the solvent, and the residue was separated by column chromatography (elution solvent: ethyl acetate / n-hexane) to obtain the target product I-16 (61% yield); 1 H NMR(500MHz, CDCl3)δ:7.39-7.35(m,2H),7.33-7.29(m,2H),7.26-7.25(m,1H),7.13-7.11 (m,5H),5.34-5.32(m,1H),5.27-5.25(m,1H),4.15(d,J=14.0Hz,1H),3.50(d,J=14.5Hz ,1H),3.22(d,J=12.0Hz,1H),2.61(d,J=12.5Hz,1H),2.25(d,J=14.5Hz,1H),1.81(d,J= 14.5Hz,1H),0.94(s,9H); 13 C NMR (126MHz, CDCl3) δ: 175.8, 143.0, 138.7, 136.1, 130.6, 128.8, 127.7, 126.5, 124.8, 120.6, 110.1, 55.2, 52.4, 50.8, 49.2, 32.1, 31.8; HRMS m / z(ESI)calcd for C 23 H 28 NO([M+H] + )334.2165, found 334.2167.

[0091] Embodiment 23

[0092]

[0093] A 1,6-enyne compound (39.8 mg, 0.2 mmol) of formula 1a, N-hydroxyphthalimide ester (109.2 mg, 0.4 mmol) of formula 2h, potassium iodide (49.5 mg, 1.5 eq), triphenylphosphine (PPh3, 10.5 mg, 20 mol%), and N,N-dimethylformamide (2.0 mL) were added to a Schlenk bottle. Then, nitrogen was filled into the reaction bottle and stirred under 5 W blue light (456 nm) irradiation conditions. The reaction progress was monitored by TLC until the starting material disappeared (reaction time was 18 hours). After the reaction was completed, the reaction solution was extracted with ethyl acetate, the organic phase was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to remove the solvent, and the residue was separated by column chromatography (elution solvent: ethyl acetate / n-hexane) to obtain the target product I-17 (75% yield); 1 H NMR(500MHz, CDCl3)δ:7.73-7.71(m,2H),7.40-7.37(m,2H),7.17-7.14(m,1H), 5.22(t,J=2.0Hz,1H),5.09(t,J=2.5Hz,1H),4.43-4.41(m,2H),1.69-1.65(m,2H),1. 56-1.52(m,3H),1.48-1.45(m,2H),1.32(s,3H),1.29-1.21(m,4H),1.05-1.00(m,2H); 13 C NMR(126MHz, CDCl3)δ:177.4,146.1,139.1,128.9,124.5,119.8,107.6,52.1,50.0,40.3,39.0,32.6(2), 30.9,25.2(2),24.7; HRMS m / z(ESI)calcd for C 19 H 26 NO([M+H] + )284.2009,found 284.2005.

[0094] Embodiment 24

[0095]

[0096] A 1,6-enyne compound (45.8 mg, 0.2 mmol) of formula 1b, N-hydroxyphthalimide ester (109.2 mg, 0.4 mmol) of formula 2h, potassium iodide (49.5 mg, 1.5 eq), triphenylphosphine (PPh3, 10.5 mg, 20 mol%), and N,N-dimethylformamide (2.0 mL) were added to a Schlenk bottle. Then, nitrogen was filled into the reaction bottle and stirred under 5 W blue light (456 nm) irradiation conditions. The reaction progress was monitored by TLC until the starting material disappeared (reaction time was 18 hours). After the reaction was completed, the reaction solution was extracted with ethyl acetate, the organic phase was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to remove the solvent, and the residue was separated by column chromatography (elution solvent: ethyl acetate / n-hexane) to obtain the target product I-18 (78% yield); 1 H NMR(400MHz, CDCl3)δ:7.61-7.59(m,2H),6.93-6.90(m,2H),5.20(t,J=2.4Hz, 1H),5.07(t,J=2.4Hz,1H),4.38-4.36(m,2H),3.81(s,3H),1.70-1.64(m,3H),1.61 -1.55(m,3H),1.50-1.45(m,2H),1.31(s,3H),1.25-1.18(m,3H),1.05-0.98(m,2H); 13 C NMR(101MHz, CDCl3)δ:177.0,156.5,146.4,132.4,121.6,114.1,107.4,55.5,52.5,49.7,40.3,39.1,32.6(2), 31.0,25.2(2),24.7; HRMS m / z(ESI)calcd for C 20 H 28 NO2([M+H] + )314.2115, found 314.2111.

[0097] Embodiment 25

[0098]

[0099] A 1,6-enyne compound (42.6 mg, 0.2 mmol) of formula 1c, N-hydroxyphthalimide ester (109.2 mg, 0.4 mmol) of formula 2h, potassium iodide (49.5 mg, 1.5 eq), triphenylphosphine (PPh3, 10.5 mg, 20 mol%), and N,N-dimethylformamide (2.0 mL) were added to a Schlenk flask. Then, nitrogen was filled into the reaction flask and stirred under 5 W blue light (456 nm) irradiation conditions. The reaction progress was monitored by TLC until the starting material disappeared (reaction time was 18 hours). After the reaction was completed, the reaction solution was extracted with ethyl acetate, the organic phase was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to remove the solvent, and the residue was separated by column chromatography (elution solvent: ethyl acetate / n-hexane) to obtain the target product I-19 (77% yield); 1 H NMR(400MHz, CDCl3)δ:7.60-7.58(m,2H),7.19-7.15(m,2H),5.20(t,J=2.4Hz, 1H),5.07(t,J=2.8Hz,1H),4.39-4.38(m,2H),2.33(s,3H),1.68-1.64(m,2H),1.56 -1.51(m,3H),1.48-1.44(m,2H),1.31(s,3H),1.28-1.19(m,4H),1.03-0.98(m,2H); 13 C NMR (101MHz, CDCl3) δ: 176.1, 145.3, 135.6, 133.2, 128.4, 118.8, 106.4, 51.2, 48.8, 39.2, 38.1, 31.6, 31.5, 29.9, 24.2, 24.1, 23.7, 19.8; HRMS m / z(ESI)calcd for C 20 H 28 NO([M+H] + )298.2165, found 298.2163.

[0100] Embodiment 26

[0101]

[0102] A 1,6-enyne compound (46.6 mg, 0.2 mmol) of formula 1d, N-hydroxyphthalimide ester (109.2 mg, 0.4 mmol) of formula 2h, potassium iodide (49.5 mg, 1.5 eq), triphenylphosphine (PPh3, 10.5 mg, 20 mol%), and N,N-dimethylformamide (2.0 mL) were added to a Schlenk bottle. Then, nitrogen was filled into the reaction bottle and stirred under 5 W blue light (456 nm) irradiation conditions. The reaction progress was monitored by TLC until the starting material disappeared (reaction time was 18 hours). After the reaction was completed, the reaction solution was extracted with ethyl acetate, the organic phase was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to remove the solvent, and the residue was separated by column chromatography (elution solvent: ethyl acetate / n-hexane) to obtain the target product I-20 (72% yield); 1 H NMR(400MHz, CDCl3)δ:7.70-7.67(m,2H),7.36-7.32(m,2H),5.23(t,J=2.4Hz, 1H),5.10(t,J=2.4Hz,1H),4.42-4.35(m,2H),1.69-1.64(m,2H),1.58-1.52( m,3H),1.48-1.44(m,2H),1.31(s,3H),1.29-1.15(m,4H),1.04-0.97(m,2H); 13 C NMR(101MHz, CDCl3)δ:177.5,145.6,137.6,129.6,128.9,120.8,107.9,52.0,49.9,40.2,39.0,32.6,32.5,30.9,25.2(2),24.7; HRMS m / z(ESI)calcd for C 19 H 25 ClNO([M+H] + )318.1619, found 318.1611.

[0103] Embodiment 27

[0104]

[0105] A 1,6-enyne compound (53.4 mg, 0.2 mmol) of formula 1e, N-hydroxyphthalimide ester (109.2 mg, 0.4 mmol) of formula 2h, potassium iodide (49.5 mg, 1.5 eq), triphenylphosphine (PPh3, 10.5 mg, 20 mol%), and N,N-dimethylformamide (2.0 mL) were added to a Schlenk bottle. Then, nitrogen was filled into the reaction bottle and stirred under 5 W blue light (456 nm) irradiation conditions. The reaction progress was monitored by TLC until the starting material disappeared (reaction time was 18 hours). After the reaction was completed, the reaction solution was extracted with ethyl acetate, the organic phase was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to remove the solvent, and the residue was separated by column chromatography (elution solvent: ethyl acetate / n-hexane) to obtain the target product I-21 (60% yield); 1 H NMR(500MHz, CDCl3)δ:7.89-7.85(m,2H),7.66-7.61(m,2H),5.25(t,J=3.5Hz, 1H),5.12(t,J=8.5Hz,1H),4.44-4.41(m,2H),1.72-1.68(m,2H),1.58-1.54(m,3H),1. 48-1.45(m,2H),1.33(s,3H),1.28-1.23(m,3H),1.19-1.15(m,1H),1.04-0.97(m,2H); 13 C NMR(126MHz, CDCl3)δ:178.0,145.2,142.0,126.1(q,J C-F =3.5Hz),125.7(q,J C-F =32.5Hz),123.0,119.1,108.1,51.8,50.1,40.2,39.0,32.6,32.5,30.9,29.7,25.2,24.6; 19 F NMR (471MHz, CDCl3) δ: -62.2; HRMS m / z (ESI)calcd for C 20 H 25 F3NO([M+H] + )352.1883,found352.1887.

[0106] Embodiment 28

[0107]

[0108] A 1,6-enyne compound (42.6 mg, 0.2 mmol) of formula 1g, N-hydroxyphthalimide ester (109.2 mg, 0.4 mmol) of formula 2h, potassium iodide (49.5 mg, 1.5 eq), triphenylphosphine (PPh3, 10.5 mg, 20 mol%), and N,N-dimethylformamide (2.0 mL) were added to a Schlenk bottle. Then, nitrogen was filled into the reaction bottle and stirred under 5 W blue light (456 nm) irradiation conditions. The reaction progress was monitored by TLC until the starting material disappeared (reaction time was 18 hours). After the reaction was completed, the reaction solution was extracted with ethyl acetate, the organic phase was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to remove the solvent, and the residue was separated by column chromatography (elution solvent: ethyl acetate / n-hexane) to obtain the target product I-22 (75% yield); 1 H NMR(400MHz, CDCl3)δ:7.61(s,1H),7.47-7.44(m,1H),7.26-7.25(m,1H),6.97(d, J=7.6Hz,1H),5.21(t,J=2.4Hz,1H),5.08(t,J=2.8Hz,1H),4.40(t,J=2.4Hz,2H),2.37(s,3 H),1.66-1.62(m,2H),1.57-1.53(m,3H),1.48-1.44(m,2H),1.31(s,3H),1.26-1.18(m,4H), 1.06-0.99(m,2H); 13 C NMR(101MHz, CDCl3)δ:177.4,146.2,139.1,138.8,128.7,125.4, 120.6,116.8,107.5,52.2,50.0,40.3,39.1,32.6(2),30.9,25.2(2),24.7,21.7; HRMS m / z(ESI)calcd for C 20 H 28 NO([M+H] + )298.2165, found 298.2161.

[0109] Embodiment 29

[0110]

[0111] A 1,6-enyne compound (45.4 mg, 0.2 mmol) of formula 1h, N-hydroxyphthalimide ester (109.2 mg, 0.4 mmol) of formula 2h, potassium iodide (49.5 mg, 1.5 eq), triphenylphosphine (PPh3, 10.5 mg, 20 mol%), and N,N-dimethylformamide (2.0 mL) were added to a Schlenk flask. Then, nitrogen was filled into the reaction flask and stirred under 5 W blue light (456 nm) irradiation conditions to react. The reaction progress was monitored by TLC until the starting material disappeared (reaction time was 18 hours). After the reaction was completed, the reaction solution was extracted with ethyl acetate, the organic phase was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to remove the solvent, and the residue was separated by column chromatography (elution solvent: ethyl acetate / n-hexane) to obtain the target product I-23 (74% yield); 1 H NMR (400MHz, CDCl3) δ: 7.56 (s, 1H), 7.38-7.35 (m, 1H), 7.13 (d, J = 8.4Hz, 1H), 5.20(t,J=2.0Hz,1H),5.07(t,J=2.4Hz,1H),4.38(t,J=2.4Hz,2H),2.28(s,3H),2.24(s,3H),1.68-1 .62(m,2H),1.57-1.54(m,3H),1.50-1.45(m,2H),1.31(s,3H),1.25-1.18(m,4H),1.05-0.98(m,2H); 13 C NMR(101MHz, CDCl3)δ:177.1,146.4,137.2,136.9,133.0,129.9,121.3,117.3, 107.3,52.3,49.9,40.3,39.1,32.6,32.5,30.9,25.2(2),24.7,20.1,19.2; HRMS m / z(ESI)calcd for C 21 H 30 NO([M+H] + )312.2322, found 312.2326.

[0112] Embodiment 30

[0113]

[0114] A 1,6-enyne compound (55.0 mg, 0.2 mmol) of formula 1i, N-hydroxyphthalimide ester (109.2 mg, 0.4 mmol) of formula 2h, potassium iodide (49.5 mg, 1.5 eq), triphenylphosphine (PPh3, 10.5 mg, 20 mol%), and N,N-dimethylformamide (2.0 mL) were added to a Schlenk bottle, and then nitrogen was filled into the reaction bottle and stirred under 5 W blue light (456 nm) irradiation conditions. The reaction progress was monitored by TLC until the raw material disappeared (reaction time was 18 hours). After the reaction was completed, the reaction solution was extracted with ethyl acetate, the organic phase was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to remove the solvent, and the residue was separated by column chromatography (elution solvent: ethyl acetate / n-hexane) to obtain the target product I-24 (76% yield, Z / E>20:1); 1 H NMR(500MHz, CDCl3)δ:7.76-7.72(m,2H),7.42-7.32(m,4H),7.30-7.24(m,3H),7.17(t,J=9.0Hz,1H),6.73(s,1H),4.56(d,J=13.5Hz,1 H),4.45(d,J=13.5Hz,1H),1.83-1.75(m,2H),1.59-1.51(m,3H),1.44-1.39(m,2H),1.30(s,3H),1.15-0.95(m,4H),0.88-0.78(m,2H); 13 C NMR(126MHz, CDCl3)δ:177.6,139.0,138.0,136.7,129.0,128.6,128.1,127.2,12 5.6,124.6,119.8,53.5,50.6,40.2,37.6,32.7,32.2,31.6,25.3,25.2,25.1; HRMS m / z(ESI)calcd for C 25 H 30 NO([M+H] + )360.2322, found 360.2326.

[0115] Example 31 Reaction Mechanism Control Experiment

[0116]

[0117] 2.0 equivalents of tetramethylpiperidinium N-oxide (TEMPO) were added to the reaction of Example 1 as a free radical scavenger, and only a small amount of the target product was detected. Nuclear magnetic resonance (NMR) analysis can detect the product 3a of TEMPO combined with cyclohexane free radicals. The above results indicate that the reaction involves a free radical process.

[0118] It can be seen from this that the possible reaction mechanism of the present invention can be deduced as shown in the following formula:

[0119]

[0120] The above-described embodiments are only preferred embodiments of the present invention, and are not exhaustive of the feasible implementations of the present invention. For those skilled in the art, any obvious changes made thereto without departing from the principles and spirit of the present invention should be considered to be included in the scope of protection of the claims of the present invention.

Claims

1. A KI / PPh3-promoted decarboxylation cyclization method for 1,6-enyne and N-hydroxyphthalimide ester, characterized in that: The steps include: Add the 1,6-eneyne compound of Formula 1, the N-hydroxyphthalimide ester of Formula 2, an iodine source, a ligand and a solvent into a Schlenk reaction flask, fill the reaction flask with nitrogen and stir the reaction under 5W blue light irradiation, monitor the reaction progress by TLC or GC until the reaction of the raw materials is complete, and obtain a decarboxylation cyclization product (I) by post-treatment; In the compounds represented by Formula 1, Formula 2, and Formula I, R 1 Selected from C1-C 10 Alkyl, substituted or unsubstituted C6-C 20 Aryl; R 2 Selected from hydrogen, C1-C 10 Alkyl, substituted or unsubstituted C6-C 20 Aryl; R 3 Selected from C1-C 10 Alkyl, C6-C 20 Aryl; R 4 Selected from C1-C 10 Alkyl, C6-C 20 Aryl, wherein the substituent in the substituted or unsubstituted is selected from halogen, C1-C 10 Alkyl, C1-C 10 Halogenated alkyl, C1-C 10 an alkoxy group, a nitro group or a cyano group, The iodine source is potassium iodide, the ligand is triphenylphosphine, the amount of potassium iodide is 1.5 equivalents, the amount of triphenylphosphine is 20 mol%, and the solvent is N,N-dimethylformamide.

2. The KI / PPh3-promoted photocatalytic decarboxylation cyclization reaction method of 1,6-enyne and N-hydroxyphthalimide ester according to claim 1, characterized in that: The post-treatment operation is as follows: the reaction solution after the reaction is completed is extracted with ethyl acetate, the organic phase is dried with anhydrous sodium sulfate, filtered and concentrated under reduced pressure to remove the solvent, and the residue is separated by column chromatography, the elution solvent is: ethyl acetate / n-hexane, to obtain a decarboxylation cyclization product (I).

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