* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.
With hydrogenchloride In 1,4-dioxane; ethyl acetate at 0 - 20℃; for 2 h;
Charging a 1000 mL round bottom flask with methanol (500 mL), 2,6-diisopropylaniline (63.8 mL, 340 mmol), glyoxal (40 wt percent soln in water, 19 mL, 170 mmol), and formic acid (1 mL).Stirring the resulting mixture for 3 hours at room temperature.Filtering the yellow precipitate, (3) (Diagram D)Washing precipitate with cold methanol.Drying precipitate in vacuo overnight (70percent, 44.2 g, 238 mmol).Charging a 5 L round bottom flask with precipitate (3) (200 g, 532 mmol) and ethyl acetate (2 L).Stirring the resulting mixture until (3) was dissolved.Cooling the solution to 0° C. but this can be carried out at room temperature.Charging a 500 mL Erlenmeyer flask with paraformaldehyde (20.7 g, 690 mmol), HCl (4N in dioxane, 212 mL, 851 mmol).Stirring this solution for 10 minutes, then added.Stirring the resulting mixture for 2 hours at room temperature.Filtering precipitateDissolving precipitate in methanol (200 mL).Adding 15.0 g of sodium bicarbonate.Stirring the solution for 1 hour or until there is no more carbonation.Filtering the solution to remove the solids.Reprecipitating the product with 250 mL of diethyl etherCollecting product by filtrationWashing product with diethyl ether.Drying the product in vacuo to yield IPr.HCl (4) as a white powder (70percent, 158.25 g, 371 mmol). 1H NMR (CDCl3, 400 MHz) δ 10.1 (s, 1H), 8.15 (s, 2H), 7.57 (t, 2H, J=7.8 Hz), 7.35 (d, 4H, J=8.4 Hz), 2.43(m, 4H), 1.28 (m, 24H) 13C NMR (CDCl3, 400 MHz) δ 145, 132.1, 129.9, 126.8, 124.7, 29.1, 24.7, 23.7. Synthesis of 1,3-Bis(2,6-diisopropylphenyl)imidazolium chloride (IPr.HCl, 4)A 1000 mL round bottom flask was charged with methanol (500 mL), 2,6-diisopropylaniline (63.8 mL, 340 mmol), glyoxal (40 wt percent soln in water, 19 mL, 170 mmol), and formic acid (1 mL). The resulting mixture was allowed to stir for 3 hours at room temperature. The yellow precipitate (3) was filtered, washed with cold methanol and dried in vacuo overnight (70percent, 44.2 g, 238 mmol). A 5 L round bottom flask was charged with 3 (200 g, 532 mmol) and ethyl acetate (2 L) and the resulting mixture was stirred until 3 was dissolved. The solution was cooled to 0° C. A 500 mL Erlenmeyer flask was charged with paraformaldehyde (20.7 g, 690 mmol), HCl (4N in dioxane, 212 mL, 851 mmol). This solution was stirred for 10 minutes, then added. The resulting mixture was then stirred for 2 hours at room temperature. The precipitate was filtered, dissolved in methanol (200 mL) and 15.0 g of sodium bicarbonate was added. The solution was stirred for 1 hour or until there was no more carbonation. The solution was filtered to remove the solids and the product was reprecipitated with 250 mL of diethyl ether, collected by filtration, washed with diethyl ether and dried in vacuo to yield IPr.HCl (4) as a white powder (70percent, 158.25 g, 371 mmol). 1H NMR (CDCl3, 400 MHz) δ 10.1 (s, 1H), 8.15 (s, 2H), 7.57 (t, 2H, J=7.8 Hz), 7.35 (d, 4H, J=8.4 Hz), 2.43(m, 4H), 1.28 (m, 24H) 13C NMR (CDCl3, 400 MHz) δ 145, 132.1, 129.9, 126.8, 124.7, 29.1, 24.7, 23.7.
70%
With hydrogenchloride In 1,4-dioxane; ethyl acetate at 0 - 20℃; for 2 h;
Synthesizing of l,3-Bis(2,6-dsopropylphenyl)imidazolium chloride (IPr HCl, 4) by:; Charging a 1000 mL round bottom flask with methanol (500 mL), 2,6- diisopropylaniline (63.8 mL, 340 mmol), glyoxal (40wt percent soln in water, 19 mL, 170 mmol), and formic acid (ImL).Stirring the resulting mixture for 3 hours at room temperature. Filtering the yellow precipitate, (3) (Diagram D)Washing precipitate with cold methanol.Drying precipitate in vacuo overnight (70percent, 44.2 g, 238 mmol).Charging a 5 L round bottom flask with precipitate (3) (200 g, 532 mmol) and ethyl acetate (2 L). Stirring the resulting mixture until (3) was dissolved.Cooling the solution to 0° C but this can be carried out at room temperature.Charging a 500 mL Erlenmeyer flask with paraformaldehyde (20.7 g, 690 mmol), HCl (4N in dioxane, 212 mL, 851 mmol).Stirring this solution for 10 minutes, then added. Stirring the resulting mixture for 2 hours at room temperature.Filtering precipitateDissolving precipitate in methanol (20OmL).Adding 15.Og of sodium bicarbonate.Stirring the solution for 1 hour or until there is no more carbonation. Filtering the solution to remove the solids.Reprecipitating the product with 250 mL of diethyl etherCollecting product by filtrationWashing product with diethyl ether.Drying the product in vacuo to yield IPrHCl (4) as a white powder (70percent, 158.25g, 371 mmol). 1H NMR (CDCl3, 400 MHz) δ 10.1 (s, IH), 8.15 (s, 2H), 7.57 (t,2H, J = 7.8 Hz), 7.35 (d, 4H, J = 8.4 Hz), 2.43(m, 4H), 1.28 (m, 24H) 13C NMR (CDCl3, 400 MHz) δ 145, 132.1, 129.9, 126.8, 124.7, 29.1, 24.7, 23.7.; Synthesis of l,3-Bis(2,6-diisopropyIphenyl)imidazolium chloride (IPrηCl, 4); A l 000 mL round bottom flask was charged with methanol (500 mL), 2,6- diisopropylamline (63.8 mL, 340 mmol), glyoxal (40wt percent soln in water, 19 mL, 170 mmol), and formic acid (ImL). The resulting mixture was allowed to stir for 3 hours at room temperature. The yellow precipitate (3) was filtered, washed with cold methanol and dried in vacuo overnight (70percent, 44.2 g, 238 mmol). A 5 L round bottom flask was charged with 3 (200 g, 532 mmol) and ethyl acetate (2 L) and the resulting mixture was stirred until 3 was dissolved. The solution was cooled to 0° C. A 500 mL Erlenmeyer flask was charged with paraformaldehyde (20.7 g, 690 mmol), HCl (4N in dioxane, 212 mL, 851 mmol). This solution was stirred for 10 minutes, then added. The resulting mixture was then stirred for 2 hours at room temperature. The precipitate was filtered, dissolved in methanol (20OmL) and 15.Og of sodium bicarbonate was added. The solution was stirred for 1 hour or until there was no more carbonation. The solution was filtered to remove the solids and the product was reprecipitated with 250 mL of diethyl ether, collected by filtration, washed with <n="10"/>diethyl ether and dried in vacuo to yield IPrHCl (4) as a white powder (70percent, 158.25g, 371 mmol). 1H NMR (CDCl3, 400 MHz) δ 10.1 (s, IH), 8.15 (s, 2H), 7.57 (t, 2H, J = 7.8 Hz), 7.35 (d, 4H, J = 8.4 Hz), 2.43(m, 4H), 1.28 (m, 24H) 13C NMR (CDCl3, 400 MHz) δ 145, 132.1, 129.9, 126.8, 124.7, 29.1, 24.7, 23.7.
51.7%
Stage #1: With hydrogenchloride In toluene at 50℃; for 1 h; Stage #2: With hydrogenchloride In 1,4-dioxane at 40℃; for 40 h;
37.6 g (100 mmol) of bis(2,6-diisopropylphenyl)diazabutadiene, 1.68 g (100 mmol) of formaldehyde solid, 160 mL of toluene were added to a 500 mL three-neck round bottom flask. Stirred refluxed at 50° C. for 1 h until most of the formaldehyde dissolved. The reaction mixture was cooled to 40° C. and a solution of HCl in dioxane 58 mL (100 mmol, 1.723 mol/L) was added with a syringe.The color of the solution changed from yellow to red to brown, with the development of a white solid. The reaction was stirred and refluxed at 40° C. for 40 h, suction filtered and washed three times with THF to give a pink solid mass. About 40 mL of anhydrous ethanol was added to dissolve, the solvent was derotated, the solid was turned into a powder, and washed three times with THF to obtain 21.94 g of an off-white powder HIPrCl (yield 51.7percent).
Reference：
[1] Advanced Synthesis and Catalysis, 2016, vol. 358, # 4, p. 622 - 630
[2] Journal of the American Chemical Society, 2011, vol. 133, # 30, p. 11482 - 11484
[3] Inorganic Chemistry, 2017, vol. 56, # 8, p. 4568 - 4575
[4] Organic Process Research and Development, 2014, vol. 18, # 8, p. 1041 - 1044
[5] Patent: US7109348, 2006, B1, . Location in patent: Page/Page column 4-7
[6] Patent: WO2008/36084, 2008, A1, . Location in patent: Page/Page column 4; 6-7; 8-9
[7] European Journal of Organic Chemistry, 2012, # 31, p. 6218 - 6227
[8] Patent: CN106432307, 2017, A, . Location in patent: Paragraph 0031; 0032
[9] Journal of Organometallic Chemistry, 2007, vol. 692, # 24, p. 5390 - 5394
[10] Green Chemistry, 2018, vol. 20, # 5, p. 964 - 968
[11] ChemCatChem, 2018, vol. 10, # 11, p. 2450 - 2457
2
[ 74663-75-5 ]
[ 3188-13-4 ]
[ 250285-32-6 ]
Reference：
[1] Chemical Communications, 2011, vol. 47, # 5, p. 1559 - 1561
[2] Tetrahedron, 1999, vol. 55, # 51, p. 14523 - 14534
[3] Journal of Organic Chemistry, 2008, vol. 73, # 7, p. 2784 - 2791
[4] Journal of the American Chemical Society, 2008, vol. 130, # 31, p. 10082 - 10083
[5] Advanced Synthesis and Catalysis, 2014, vol. 356, # 11-12, p. 2539 - 2546
[6] Tetrahedron, 2012, vol. 68, # 38, p. 7949 - 7955
[7] Journal of Organometallic Chemistry, 2016, vol. 825-826, p. 55 - 62
3
[ 244187-81-3 ]
[ 250285-32-6 ]
Reference：
[1] Angewandte Chemie, International Edition, 2009, vol. 48, p. 5683 - 5686[2] Angewandte Chemie, 2009, vol. 121, p. 5793 - 5796
4
[ 50-00-0 ]
[ 74663-75-5 ]
[ 250285-32-6 ]
Reference：
[1] Angewandte Chemie - International Edition, 2018, vol. 57, # 17, p. 4668 - 4672[2] Angew. Chem., 2018, vol. 130, # 17, p. 4758 - 4762,5
[3] Journal of Organometallic Chemistry, 2000, vol. 606, # 1, p. 49 - 54
[4] Organic Letters, 2016, vol. 18, # 3, p. 432 - 435
Reference：
[1] Angewandte Chemie - International Edition, 2013, vol. 52, # 52, p. 14204 - 14208[2] Angew. Chem., 2013, vol. 125, # 52, p. 14454 - 14458,5
13
[ 131543-46-9 ]
[ 24544-04-5 ]
[ 3188-13-4 ]
[ 250285-32-6 ]
Reference：
[1] Angewandte Chemie - International Edition, 2010, vol. 49, # 16, p. 2929 - 2932
14
[ 250285-32-6 ]
[ 578743-87-0 ]
Yield
Reaction Conditions
Operation in experiment
94%
With sodium t-butanolate In tetrahydrofuran at 20℃; for 20 h;
Synthesis of [(IPr)CuCl]. This synthesis is as reported in the literature; see H. Kaur et al., Organometallics 2004, 23, 1157-1160. In a 250 mL Schlenk flask were added copper(I) chloride (1.0 g, 10.10 mmol), 1,3-bis(2,6-diisopropylphenyl)imidazolium chloride (IPr.HCl; 4.29 g, 10.10 mmol), and sodium tert-butoxide (0.97 g, 10.10 mmol). To this flask, dry tetrahydrofuran (100 mL) was added under an inert atmosphere of argon, and the mixture was magnetically stirred for 20 hours at room temperature. After the mixture was filtered through a plug of Celite and then evaporating the solvent under vacuum, a white solid was obtained (4.59 g, 9.40 mmol, 94percent). 1H NMR: (400 MHz, acetone-d6, ppm) δ=1.21 (d, J=6.8 Hz, 12H); 1.30 (d, J=6.8 Hz, 12H); 2.57 (hep, J=6.8 Hz, 4H); 7.12 (s, 2H). 7.29 (d, J=7.8 Hz, 4H); 7.49 (t, J=7.8 Hz, 2H). 13C NMR: (100 MHz, acetone-d6, ppm) δ=182.32; 145.61; 134.41; 130.62; 124.25; 123.13; 28.76; 24.82; 23.87. Elemental analysis calcd for C27H36ClCuN2: C 66.64percent, H, 7.46percent, N, 5.76percent; found C, 66.70percent, H, 7.48percent, N, 6.06percent.
Reference：
[1] Organometallics, 2004, vol. 23, # 5, p. 1157 - 1160
[2] Patent: US2009/69569, 2009, A1, . Location in patent: Page/Page column 6
[3] Organometallics, 2013, vol. 32, # 15, p. 4279 - 4283
[4] Organic and Biomolecular Chemistry, 2012, vol. 10, # 47, p. 9334 - 9337
[5] Journal of the American Chemical Society, 2017, vol. 139, # 36, p. 12855 - 12862
[6] Journal of the American Chemical Society, 2015, vol. 137, # 4, p. 1424 - 1427
[7] Dalton Transactions, 2017, vol. 46, # 27, p. 8756 - 8762
15
[ 12775-96-1 ]
[ 250285-32-6 ]
[ 578743-87-0 ]
Yield
Reaction Conditions
Operation in experiment
40%
at 80 - 90℃; for 30 h;
Add ligand L8850mg (2.0mmol), copper powder 128mg (2.0mmol) in 50mL flask, water 30 mL, 80 ~ 90 in an oil bath, the reaction was stirred for 30 hours, the reaction mixture was cooled to room temperature, filtered, the filter cake was washed 3 times with water, the filter cake dissolved in acetonitrile and filtered to remove unreacted copper powder, the solvent was evaporated under reduced pressure to give 390 mg of colorless crystals, a yield of 40percent.
Reference：
[1] Dalton Transactions, 2015, vol. 44, # 4, p. 1836 - 1844
[2] Chemical Science, 2017, vol. 8, # 2, p. 1086 - 1089
[3] Chemical Communications, 2012, vol. 48, # 40, p. 4887 - 4889
[4] Patent: CN105585584, 2016, A, . Location in patent: Paragraph 0046; 0047; 0048
In tetrahydrofuran at 20℃; for 24h; Molecular sieve; Inert atmosphere;
65%
With air In tetrahydrofuran; water at 40℃; for 16h;
1.2; 1.2; 2.2; 3.2 Step 2, Synthesis of 1,3-bis(2,6-diisopropylphenyl)imidazolium chloride
In the air, add glyoxal-bis-(2,6-diisopropylphenyl)imine (250mmol),Tetrahydrofuran (500mL) and a small amount of water (0.225mL,That is, the molar ratio of glyoxal-bis-(2,6-diisopropylphenyl)imine to water is 1:5%) is added to the reaction flask,Then add chloromethyl ethyl ether (250mmol), and the mixture is stirred and reacted at 40°C for 16 hours. After the reaction is complete, filter the resulting precipitate and wash it thoroughly with n-pentane,After vacuum drying, 1,3-bis(2,6-diisopropylphenyl)imidazolium chloride (white solid) was obtained with a yield of 65%.
47%
With water In tetrahydrofuran at 40℃; for 16h;
45%
In tetrahydrofuran at 40℃;
43%
In tetrahydrofuran
36%
In tetrahydrofuran; water at 35℃; for 16h;
In tetrahydrofuran at 40℃; for 18h; Inert atmosphere;
4.3.1.2. Preparation of IMes·HCl (1a)
General procedure: In a flask, the imine (3.0 g, 10 mmol) was dissolved in tetrahydrofuran (25 ml), followed by dropwise addition of chloromethyl ethyl ether (1.04 g, 11 mmol), the mixture was stirred under N2 at 40 °C for 18 h, and then ethyl ether (25 ml) was added to separate white solid, the solid was filtered and washed with ethyl ether, the white solid was dried under vacuum affording 2.2 g IMes·HCl in 65% yield.
In tetrahydrofuran
at 100℃; for 24h; Inert atmosphere; Sealed tube;
Procedure for the Synthesis of Imidazolium Salt B4.
General procedure: α-Diimine compound A4 (0.93 g, 2 mmol) and chloromethyl ethyl ether (75 mmol, 7 mL) were added to a thick-walled reaction vessel under a nitrogen atmosphere. The vessel was sealed and the mixture was allowed to heat at 100 oC for 24 h. After cooled to room temperature, the reaction mixture was treated with hexane and stirred for another 24 h, causing the formation of a great deal of precipitate. The solid was isolated by filtration and washed three times with hexane. The resulting product was obtained as yellowish powder in 52% yield. B4: 1H NMR (400 MHz, CDCl3) δ 11.32 (s, 1H), 7.98 (d, J = 8.3 Hz, 2H), 7.61 - 7.52 (m, 2H), 7.30 (d, J = 7.0 Hz, 2H), 7.14 (s, 6H), 2.42 (s, 6H), 2.32 (s, 12H). 13C NMR (101 MHz, CDCl3) δ 142.38 (s), 141.43 (s), 136.62 (s), 134.16 (s), 130.53 (s), 130.23 (d, J = 5.2 Hz), 129.80 (d, J = 10.8 Hz), 128.21 (s), 123.46 (s), 122.89 (s), 100.00 (s), 77.40 (s), 77.08 (s), 76.76 (s), 21.34 (s), 17.98 (s).
40 %
In tetrahydrofuran at 40℃; Inert atmosphere; Schlenk technique;
1.1-3.1; 1.1-2.1
(1) Under a nitrogen atmosphere, take diimine (3.76g, 10.00mmol) in a 100mL Schlenk reaction flask, add 25mL of anhydrous THF to dissolve it, and add chloromethyl ether (1.04g, 11.00mmol) dropwise to the reaction bottle, heated to 40°C for 18h with stirring. After the reaction was completed, 25 mL of anhydrous ether was added thereto, stirred and left to stand for treatment, a white solid precipitated out, and the solvent was filtered through a double-ended needle with filter paper at one end. After absorbing the solvent, add a small amount of absolute ethanol to the solid to dissolve it, then add a large amount of anhydrous ether to precipitate the solid, cool it and let it stand for filtration; repeat this step 3 times, and finally a white solid precipitate is obtained. Vacuum drying was carried out to finally obtain 1.70 g of white 1,3-bis-(2,6-diisopropylphenyl)imidazolium chloride salt with a molar yield of 40%.
With chloro-trimethyl-silane In ethyl acetate at 70℃; for 2h;
89%
With chloro-trimethyl-silane In ethyl acetate at 70℃; for 2h;
4.3. Preparation of the catalyst
i. A mixture of 2,6-diisopropylaniline (33.9 mmol) and HOAc (1.18 mmol) and 15 mL MeOH was stirred in at 50 °C, then slowly dropwise added 15 mL of a MeOH solution of glyoxal (40% aqueous solution, 16.7 mmol) in 15 minutes. After the addition, the mixture continuing to stir at 50 °C for 30 minutes and then at room temperature for 10 hours. The reaction mixture was filtered dried to obtain 5.6 g of yellow compound a[57] (87% yield). ii. a (8.5 mmol) and paraformaldehyde (8.5 mmol) were added into 30 mL EtOAc and stirred vigorously to dissolve at 70 °C. Then, 20 mL of TMSCl (0.85 mmol) in EtOAc was slowly added dropwise to the reaction flask within 20 minutes. After reacting for 2 h, the reaction mixture is cooled to 10 °C and filtered. The filter cake was washed with EtOAc and dried to obtain 3.2 g of compound b[57] as a white solid (89% yield).
86%
With hydrogenchloride In 1,4-dioxane; ethyl acetate at 20℃; for 17h;
47%
Stage #1: formaldehyd; (1E,2E)-N<SUP>1</SUP>,N<SUP>2</SUP>-bis(2,6-diisopropylphenyl)ethane-1,2-diimine In toluene at 100℃;
Stage #2: With hydrogenchloride In 1,4-dioxane; toluene at 70℃; for 5h;
41%
With hydrogenchloride In 1,4-dioxane; ethyl acetate at 20℃; Heating;
92.5 %
With chloro-trimethyl-silane In ethyl acetate at 70℃;
1.1 Synthesis procedures for intermediate product 2 in formula (R2) are described.
3.80 g (10.08 mmol) of (1E,2E)-1,2-bis(2,6-diisopropylphenylimino)ethane in a 500 mL eggplant flask, 0.32 g (10.66 mmol) of paraformaldehyde and 83 mL of ethyl acetate were added and heated to 70 °C. The mixed liquid was in a yellow slurry-like solution state. Next, a mixed solution of 0.34 mL (10.66 mmol) of chlorotrimethylsilane and 8 mL of ethyl acetate was added dropwise over 20 minutes. After that, the mixture was stirred at 70 °C for 2 hours. The color of the solvent changed from yellow to orange.After completion of the reaction, the reaction mixture was immersed in ice water and cooled to 0°C.After cooling, it was filtered through a membrane filter and the solid was washed with ethyl acetate.After that, it was vacuum-dried to obtain a pale pink powdery solid.The yield of intermediate product 2 (white powdery solid) in formula (R2) was 3.96 g, yield 92.5%.
With chloro-trimethyl-silane In ethyl acetate at 70℃; for 2h;
88.4%
Stage #1: formaldehyd With hydrogenchloride In 1,4-dioxane at 30℃; for 12h;
Stage #2: 1,2-bis(2,6-diisopropylphenylimino)ethane In tetrahydrofuran; 1,4-dioxane at 20℃; for 4h;
1-4
The paraformaldehyde and HCl (4M in dioxane) were stirred at 30°C for 12h, and then added to the mixture of diazabutadiene and THF, and the reaction was continued to be stirred at room temperature for 4h, and filtered and washed to obtain the 1, 3-bis(2,6-diisopropyl-1-phenyl)imidazolium chloride; the molar ratio of the diazabutadiene, the paraformaldehyde and the HCl is 1:1:1 ; The yield of 1,3-bis(2,6-diisopropyl-1-phenyl) imidazolium chloride was 88.4%;
87%
With chloro-trimethyl-silane In ethyl acetate at 70℃; for 2h; Inert atmosphere; Glovebox;
86%
With chloro-trimethyl-silane In ethyl acetate at 70℃; for 2.75h; Inert atmosphere;
86%
With chloro-trimethyl-silane In ethyl acetate at 70℃; for 2.75h;
In the air, dissolve N,N'-1,4-bis(2,6-diisopropylphenyl)-1,4-diazabutadiene (S1) with 5.4L EtOAc(226g, 0.600mol, 1.00equiv) and paraformaldehyde(18.1g, 0.603mol),TMSCl (76.5mL, 0.603mol, 1.03equiv) dissolved in 80mL EtOAc was slowly added dropwise to the mixed solution within 45 minutes,The reaction mixture was stirred at 70°C for 2 hours. After the reaction, the reaction solution was cooled to 10°C, and the reaction mixture was filtered. The filter cake was washed with EtOAc (3×500 mL) and dried to obtain S2 as a colorless solid
83%
With chloro-trimethyl-silane In ethyl acetate at 70℃; for 4.5h;
76%
With chloro-trimethyl-silane In ethyl acetate at 70℃;
75%
With chloro-trimethyl-silane In ethyl acetate at 70℃;
70%
With hydrogenchloride In 1,4-dioxane; ethyl acetate at 0 - 20℃; for 2h;
D; 1
Charging a 1000 mL round bottom flask with methanol (500 mL), 2,6-diisopropylaniline (63.8 mL, 340 mmol), glyoxal (40 wt % soln in water, 19 mL, 170 mmol), and formic acid (1 mL).Stirring the resulting mixture for 3 hours at room temperature.Filtering the yellow precipitate, (3) (Diagram D)Washing precipitate with cold methanol.Drying precipitate in vacuo overnight (70%, 44.2 g, 238 mmol).Charging a 5 L round bottom flask with precipitate (3) (200 g, 532 mmol) and ethyl acetate (2 L).Stirring the resulting mixture until (3) was dissolved.Cooling the solution to 0° C. but this can be carried out at room temperature.Charging a 500 mL Erlenmeyer flask with paraformaldehyde (20.7 g, 690 mmol), HCl (4N in dioxane, 212 mL, 851 mmol).Stirring this solution for 10 minutes, then added.Stirring the resulting mixture for 2 hours at room temperature.Filtering precipitateDissolving precipitate in methanol (200 mL).Adding 15.0 g of sodium bicarbonate.Stirring the solution for 1 hour or until there is no more carbonation.Filtering the solution to remove the solids.Reprecipitating the product with 250 mL of diethyl etherCollecting product by filtrationWashing product with diethyl ether.Drying the product in vacuo to yield IPr.HCl (4) as a white powder (70%, 158.25 g, 371 mmol). 1H NMR (CDCl3, 400 MHz) δ 10.1 (s, 1H), 8.15 (s, 2H), 7.57 (t, 2H, J=7.8 Hz), 7.35 (d, 4H, J=8.4 Hz), 2.43(m, 4H), 1.28 (m, 24H) 13C NMR (CDCl3, 400 MHz) δ 145, 132.1, 129.9, 126.8, 124.7, 29.1, 24.7, 23.7. Synthesis of 1,3-Bis(2,6-diisopropylphenyl)imidazolium chloride (IPr.HCl, 4)A 1000 mL round bottom flask was charged with methanol (500 mL), 2,6-diisopropylaniline (63.8 mL, 340 mmol), glyoxal (40 wt % soln in water, 19 mL, 170 mmol), and formic acid (1 mL). The resulting mixture was allowed to stir for 3 hours at room temperature. The yellow precipitate (3) was filtered, washed with cold methanol and dried in vacuo overnight (70%, 44.2 g, 238 mmol). A 5 L round bottom flask was charged with 3 (200 g, 532 mmol) and ethyl acetate (2 L) and the resulting mixture was stirred until 3 was dissolved. The solution was cooled to 0° C. A 500 mL Erlenmeyer flask was charged with paraformaldehyde (20.7 g, 690 mmol), HCl (4N in dioxane, 212 mL, 851 mmol). This solution was stirred for 10 minutes, then added. The resulting mixture was then stirred for 2 hours at room temperature. The precipitate was filtered, dissolved in methanol (200 mL) and 15.0 g of sodium bicarbonate was added. The solution was stirred for 1 hour or until there was no more carbonation. The solution was filtered to remove the solids and the product was reprecipitated with 250 mL of diethyl ether, collected by filtration, washed with diethyl ether and dried in vacuo to yield IPr.HCl (4) as a white powder (70%, 158.25 g, 371 mmol). 1H NMR (CDCl3, 400 MHz) δ 10.1 (s, 1H), 8.15 (s, 2H), 7.57 (t, 2H, J=7.8 Hz), 7.35 (d, 4H, J=8.4 Hz), 2.43(m, 4H), 1.28 (m, 24H) 13C NMR (CDCl3, 400 MHz) δ 145, 132.1, 129.9, 126.8, 124.7, 29.1, 24.7, 23.7.
70%
With hydrogenchloride In 1,4-dioxane; ethyl acetate at 0 - 20℃; for 2h;
1; D
Synthesizing of l,3-Bis(2,6-dsopropylphenyl)imidazolium chloride (IPr HCl, 4) by:; Charging a 1000 mL round bottom flask with methanol (500 mL), 2,6- diisopropylaniline (63.8 mL, 340 mmol), glyoxal (40wt % soln in water, 19 mL, 170 mmol), and formic acid (ImL).Stirring the resulting mixture for 3 hours at room temperature. Filtering the yellow precipitate, (3) (Diagram D)Washing precipitate with cold methanol.Drying precipitate in vacuo overnight (70%, 44.2 g, 238 mmol).Charging a 5 L round bottom flask with precipitate (3) (200 g, 532 mmol) and ethyl acetate (2 L). Stirring the resulting mixture until (3) was dissolved.Cooling the solution to 0° C but this can be carried out at room temperature.Charging a 500 mL Erlenmeyer flask with paraformaldehyde (20.7 g, 690 mmol), HCl (4N in dioxane, 212 mL, 851 mmol).Stirring this solution for 10 minutes, then added. Stirring the resulting mixture for 2 hours at room temperature.Filtering precipitateDissolving precipitate in methanol (20OmL).Adding 15.Og of sodium bicarbonate.Stirring the solution for 1 hour or until there is no more carbonation. Filtering the solution to remove the solids.Reprecipitating the product with 250 mL of diethyl etherCollecting product by filtrationWashing product with diethyl ether.Drying the product in vacuo to yield IPrHCl (4) as a white powder (70%, 158.25g, 371 mmol). 1H NMR (CDCl3, 400 MHz) δ 10.1 (s, IH), 8.15 (s, 2H), 7.57 (t,2H, J = 7.8 Hz), 7.35 (d, 4H, J = 8.4 Hz), 2.43(m, 4H), 1.28 (m, 24H) 13C NMR (CDCl3, 400 MHz) δ 145, 132.1, 129.9, 126.8, 124.7, 29.1, 24.7, 23.7.; Synthesis of l,3-Bis(2,6-diisopropyIphenyl)imidazolium chloride (IPrηCl, 4); A l 000 mL round bottom flask was charged with methanol (500 mL), 2,6- diisopropylamline (63.8 mL, 340 mmol), glyoxal (40wt % soln in water, 19 mL, 170 mmol), and formic acid (ImL). The resulting mixture was allowed to stir for 3 hours at room temperature. The yellow precipitate (3) was filtered, washed with cold methanol and dried in vacuo overnight (70%, 44.2 g, 238 mmol). A 5 L round bottom flask was charged with 3 (200 g, 532 mmol) and ethyl acetate (2 L) and the resulting mixture was stirred until 3 was dissolved. The solution was cooled to 0° C. A 500 mL Erlenmeyer flask was charged with paraformaldehyde (20.7 g, 690 mmol), HCl (4N in dioxane, 212 mL, 851 mmol). This solution was stirred for 10 minutes, then added. The resulting mixture was then stirred for 2 hours at room temperature. The precipitate was filtered, dissolved in methanol (20OmL) and 15.Og of sodium bicarbonate was added. The solution was stirred for 1 hour or until there was no more carbonation. The solution was filtered to remove the solids and the product was reprecipitated with 250 mL of diethyl ether, collected by filtration, washed with diethyl ether and dried in vacuo to yield IPrHCl (4) as a white powder (70%, 158.25g, 371 mmol). 1H NMR (CDCl3, 400 MHz) δ 10.1 (s, IH), 8.15 (s, 2H), 7.57 (t, 2H, J = 7.8 Hz), 7.35 (d, 4H, J = 8.4 Hz), 2.43(m, 4H), 1.28 (m, 24H) 13C NMR (CDCl3, 400 MHz) δ 145, 132.1, 129.9, 126.8, 124.7, 29.1, 24.7, 23.7.
70%
With chloro-trimethyl-silane In ethyl acetate at 70℃; for 2.75h; Inert atmosphere; Schlenk technique;
65%
With hydrogenchloride In 1,4-dioxane; ethyl acetate
55%
With hydrogenchloride In diethyl ether; toluene at 20 - 80℃; for 41h; Inert atmosphere;
51.7%
Stage #1: formaldehyd; 1,2-bis(2,6-diisopropylphenylimino)ethane With hydrogenchloride In toluene at 50℃; for 1h;
Stage #2: With hydrogenchloride In 1,4-dioxane at 40℃; for 40h;
1.1 1) Before preparing the rare earth imidazolium salt, HIPrCl is first prepared and its preparation method is as follows:
37.6 g (100 mmol) of bis(2,6-diisopropylphenyl)diazabutadiene, 1.68 g (100 mmol) of formaldehyde solid, 160 mL of toluene were added to a 500 mL three-neck round bottom flask. Stirred refluxed at 50° C. for 1 h until most of the formaldehyde dissolved. The reaction mixture was cooled to 40° C. and a solution of HCl in dioxane 58 mL (100 mmol, 1.723 mol/L) was added with a syringe.The color of the solution changed from yellow to red to brown, with the development of a white solid. The reaction was stirred and refluxed at 40° C. for 40 h, suction filtered and washed three times with THF to give a pink solid mass. About 40 mL of anhydrous ethanol was added to dissolve, the solvent was derotated, the solid was turned into a powder, and washed three times with THF to obtain 21.94 g of an off-white powder HIPrCl (yield 51.7%).
46.7%
With chloro-trimethyl-silane In ethyl acetate at 70℃; for 4h;
Stage #1: formaldehyd; 1,2-bis(2,6-diisopropylphenylimino)ethane In toluene at 100℃; for 3h;
Stage #2: With hydrogenchloride In toluene at 70℃; for 5h; Further stages.;
273 mg
With hydrogenchloride In 1,4-dioxane for 3h; Milling; Green chemistry;
2.51 g
With hydrogenchloride In tetrahydrofuran; 1,4-dioxane at 0 - 20℃; Inert atmosphere; Schlenk technique;
With chloro-trimethyl-silane In ethyl acetate Schlenk technique; Inert atmosphere;
87 %
With chloro-trimethyl-silane In ethyl acetate at 70℃;
81 %
With chloro-trimethyl-silane In ethyl acetate Heating;
86 %
With chloro-trimethyl-silane In ethyl acetate at 70℃;
3 Revised procedure: N,N′-1,3-bis(2,6-diisopropylphenypimidazolium chloride (S2)
In air, to N,N′-1,4-bis(2,6-diisopropylphenyI)-1,4-diaza-butadiene (S1) (8.9 g, 23.9 mmol, 1.00 equiv) and paraformaldehyde (750 mg, 24.6 mmol, 1.03 equiv) was added 50 mL of EtOAc. A solution of TMSCI (3.3 mL, 24.6 mmol, 1.03 equiv) in 15 mL of EtOAc was then added at 70° C., dropwise, over 45 min, with vigorous stirring. The reaction mixture was stirred at 70° C. for 2 h. After cooling to 10° C. with stirring, the reaction mixture was filtered. The filter cake was washed with EtOAc (3×25 mL) and dried in vacuo at 75 mbar for 3 hours at 40° C.[1] to afford 8.7 g of compound S2 as a colourless solid (86% yield).
With sodium t-butanolate; In tetrahydrofuran; at 20℃; for 20h;
Synthesis of [(IPr)CuCl]. This synthesis is as reported in the literature; see H. Kaur et al., Organometallics 2004, 23, 1157-1160. In a 250 mL Schlenk flask were added copper(I) chloride (1.0 g, 10.10 mmol), 1,3-bis(2,6-diisopropylphenyl)imidazolium chloride (IPr.HCl; 4.29 g, 10.10 mmol), and sodium tert-butoxide (0.97 g, 10.10 mmol). To this flask, dry tetrahydrofuran (100 mL) was added under an inert atmosphere of argon, and the mixture was magnetically stirred for 20 hours at room temperature. After the mixture was filtered through a plug of Celite and then evaporating the solvent under vacuum, a white solid was obtained (4.59 g, 9.40 mmol, 94%). 1H NMR: (400 MHz, acetone-d6, ppm) delta=1.21 (d, J=6.8 Hz, 12H); 1.30 (d, J=6.8 Hz, 12H); 2.57 (hep, J=6.8 Hz, 4H); 7.12 (s, 2H). 7.29 (d, J=7.8 Hz, 4H); 7.49 (t, J=7.8 Hz, 2H). 13C NMR: (100 MHz, acetone-d6, ppm) delta=182.32; 145.61; 134.41; 130.62; 124.25; 123.13; 28.76; 24.82; 23.87. Elemental analysis calcd for C27H36ClCuN2: C 66.64%, H, 7.46%, N, 5.76%; found C, 66.70%, H, 7.48%, N, 6.06%.
(1,3-bis(2,6-isopropylphenyl)-1H-imidazol-2(3H)-ylidene)copper(I) iodide[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
81%
With KOCH3 In toluene mixing copper compd., imidazolium deriv. and potassium metylate under Ar, stirring in dry toluene for 15 h at room temp.; filtration through celite, eluting with CH2Cl2, mixing with pentane, filtration, elem. anal.;
60%
With potassium carbonate In acetone at 20 - 60℃; for 24h; Sealed tube;
53%
With potassium <i>tert</i>-butylate In tetrahydrofuran at 20℃; for 4h; Inert atmosphere; Schlenk technique;
With potassium carbonate In acetone at 60℃; for 24h;
[1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene](3-chloropyridyl)palladium(ll) dichloride[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
91%
With caesium carbonate at 90℃; for 16h;
1.3; 1.3; 2.3; 3.3 Step 3, Synthesis of NHC-PdCl2-3-chloropyridine complex ([1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene](3-chloropyridyl)palladium(II) dichloride)
In the air, add palladium chloride (53mmol), 1,3-bis(2,6-diisopropylphenyl) imidazolium chloride (59mmol),Cesium carbonate (267mmol) and 3-chloropyridine (2239mmol) were added to the reaction flask, and the mixture was stirred and reacted at 90°C for 16 hours. After the reaction is completed, cool to room temperature, add dichloromethane to dilute, filter the precipitate, and wash thoroughly with dichloromethane,Concentrate the filtrate and vacuum dry to obtain a yellow solid NHC-PdCl2-3-chloropyridine complex ([1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene](3-chloropyridyl)palladium(II) dichloride), the yield was 91%.
89%
With potassium carbonate at 80℃; Schlenk technique;
88%
With potassium carbonate at 200℃; for 0.75h; Microwave irradiation; Inert atmosphere;
2
A microwave -vial was loaded with NHC HCl (0.55 mmol), palladium(II) chloride (89 mg, 0.50 mmol), potassium carbonate (345 mg, 2.5 mmol), 3-chloropyridine (2 mL) and a magnetic bar. The mixture was heated in a microwave reactor for 45 min at 200 °C. The mixture was diluted with methylene chloride, filtered over a plug of silica gel that was covered with celite and the silica gel was rinsed with methylene chloride. The solvent and excess chloropyridine were removed in vacuo, the product was triturated in pentane and the pentane was decanted. Drying in vacuo afforded the desired products as yellow solids.(IPr)PdCl2(3-chloropyridine):309 mg (88 %) of the title compound were obtained using IPr-HCl (234 mg, 0.550 mmol). 1H NMR (300 MHz, CDCI3): δ (ppm) = 8.60 (d, 3J= 2.4 Hz, 1H), 8.52 (dd, 3J = 5.5 Hz, 3J= 1.3 Hz, 1H), 7.55 (ddd, 3J= 8.2 Hz, 3J= 2.3 Hz, 3J= 1.3 Hz, 1H), 7.50 (t, 3J = 7.8 Hz, 2H), 7.35 (d, 3J= 7.7 Hz, 4H), 7.14 (s, 2H), 7.07 (dd, 3J= 8.2 Hz, 3J= 5.5 Hz), 3.16 (sept, 3J= 6.7 Hz, 4H), 1.48 (d, 3J= 6.6 Hz, 12H), 1.12 (d, 3J= 6.9 Hz, 12H).
82%
With potassium carbonate at 80℃; for 16h; Schlenk technique; Inert atmosphere;
70%
With potassium carbonate at 70℃; for 6h;
4.3.1 General procedure I
General procedure: A flask was charged with imidazolium or dihydroimidazolium halide (1 equiv.), palladium(II) chloride (1.3 equiv.), potassium carbonate (4.2 equiv.) and 3-substituted pyridine. The mixture was stirred at 70 °C for 6 h. After cooling to room temperature, the reaction mixture was diluted with dichloromethane and filtered through a short pad of silica gel topped with celite. The filtrate was evaporated with a rotary vacuum evaporator and the solid residue was dried in vacuum. The crude product was purified by column chromatography.
69%
With potassium carbonate at 80℃; for 16h; Inert atmosphere; Schlenk technique; Sealed tube;
47%
With potassium carbonate at 90℃; for 24h; Sealed tube;
47%
With potassium carbonate at 90℃; for 24h; Sealed tube;
With potassium <i>tert</i>-butylate In tetrahydrofuran at 20℃; for 4h;
1-4
Mix 1,3-bis(2,6-diisopropyl-1-phenyl)imidazolium chloride and potassium tert-butoxide according to the molar ratio of 1:1 and add them to the first organic solvent THF, and stir for 4h at room temperature. The free nitrogen heterocyclic carbene was extracted by ethyl acetate, dried and purified to obtain the free nitrogen heterocyclic carbene; the yield of free nitrogen heterocyclic carbene was 66.7%
Multi-step reaction with 3 steps
1.1: potassium <i>tert</i>-butylate / tetrahydrofuran / 20 °C / Inert atmosphere
1.2: 20 °C / Inert atmosphere
2.1: potassium <i>tert</i>-butylate / tetrahydrofuran / 24 h / 20 °C / Inert atmosphere
3.1: air
Add ligand L8850mg (2.0mmol), copper powder 128mg (2.0mmol) in 50mL flask, water 30 mL, 80 ~ 90 in an oil bath, the reaction was stirred for 30 hours, the reaction mixture was cooled to room temperature, filtered, the filter cake was washed 3 times with water, the filter cake dissolved in acetonitrile and filtered to remove unreacted copper powder, the solvent was evaporated under reduced pressure to give 390 mg of colorless crystals, a yield of 40%.
Stage #1: 1,3-bis[2,6-diisopropylphenyl]imidazolium chloride With silver(l) oxide In dichloromethane at 30℃; for 3h; Inert atmosphere;
Stage #2: chloro(dimethylsulfide) gold(I) In dichloromethane at 30℃; for 3h; Inert atmosphere;
75%
Stage #1: 1,3-bis[2,6-diisopropylphenyl]imidazolium chloride With silver(l) oxide In dichloromethane at 20℃; for 3h;
Stage #2: chloro(dimethylsulfide) gold(I) In dichloromethane for 4h;
1.2.2.1 General Procedure for NHC Au(I) Complexes-neutral
General procedure: Ag2O (0.5 mmol) was added to a solution of the imidazolium ligand (1mmol) in CH2Cl2. The suspension became clear after stirring 3 h at room temperature. Then a solution of Me2SAuCl (1mmol) in CH2Cl2 was added dropwise. The reaction mixture was stirred for another 4 h. Then the solution was filtered through Celite and the solvent evaporated to leave a volume of ca. 3 ml. The addition of hexane led to the precipitation of a white solid.
With potassium carbonate In acetone at 60℃; for 1h;
With potassium carbonate In acetone at 60℃; for 1h;
With potassium <i>tert</i>-butylate In tetrahydrofuran at 20℃; for 1h; Inert atmosphere;
47%
Stage #1: 1,3-bis[2,6-diisopropylphenyl]imidazolium chloride With sodium hexamethyldisilazane In tetrahydrofuran at 20℃; for 1h; Schlenk technique; Inert atmosphere;
Stage #2: platinum(0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex In tetrahydrofuran at 20℃; Schlenk technique; Inert atmosphere;
General procedure for preparation of (NHC)Pt(dvtms)
General procedure: A 10 ml Schlenk flask equipped with a magnetic stir bar was charged with 1.2 mmol (1.2 eq.) of corresponding azolium (or amidinium) salt and evacuated to 0.1-0.2 mmHg. The Schlenk flask was heated at 100 °C/0.1 mmHg for 1h. The flask was filled with argon and allowed to cool to room temperature followed by addition of 6 ml of dry THF. The reaction mixture was stirred for 5 min and 1.2 ml of a 1M NaHMDS in THF was added (2.4 ml for (7-Dipp)Pt(dvtms)). The reaction mixture was allowed to stir for 1 h at room temperature and 1.0 mmol of Pt2(dvtms)3 in dvtms was added. The light yellow solution was stirred overnight, and then it was transferred to a 100 ml round-bottomed flask with dichloromethane and evaporated to dryness. The solids were triturated with 20 ml of dichloromethane and filtered through a 1 cm pad of silica gel eluting with 3x20 ml of CH2Cl2. The filtrate was evaporated to dryness; the solids were triturated with 3x1 ml of n-pentane to give a pure complex as white microcrystalline solid
255 mg
With potassium <i>tert</i>-butylate In tetrahydrofuran at 20℃; for 1h; Inert atmosphere;
Stage #1: chloro(dimethylsulfide) gold(I); 1,3-bis[2,6-diisopropylphenyl]imidazolium chloride With potassium <i>tert</i>-butylate In tetrahydrofuran at 20℃; for 2h;
Stage #2: With potassium <i>tert</i>-butylate In tetrahydrofuran; toluene at 20℃; for 3h;
Stage #3: water for 0.5h;
4.3 General procedure for the one-pot synthesis of [Au(NHC)(OH)]
A vial was charged with [Au(SMe2)Cl] (53mg, 190μmol, 1.06 equiv.), IPr.HCl (76mg, 179μmol, 1 equiv.) and KOtBu (31mg, 277μmol, 1.5 equiv.) in THF (0.5mL), under air. The mixture was stirred for 2h at room temperature. KOtBu (62mg, 553μmol, 3 equiv.) was then added followed by toluene (0.5mL). After 3h at room temperature, the crude mixture was then filtered through Celite and washed with additional THF. Water (0.1mL) was added to the solution and the solution was stirred for an additional 15min. THF was then removed under vacuum. More water was added to the white, cloudy suspension and the product was vigorously stirred for a few minutes. It was left to settle for 10min, collected using a Buchner funnel and washed with hexane. It was then dried under vacuum for several days to produce a white microcrystalline solid.
With potassium <i>tert</i>-butylate In tetrahydrofuran at 20℃; for 3h; Schlenk technique; Inert atmosphere;
Preparation of NHC-palladacycles 3-10
General procedure: A mixture of pyrazine ligand 1 or 2 (1mmol), Li2PdCl4 (1mmol) and NaOAc (1mmol) in 20mL of dry methanol was stirred for 24hat rt. The yellow solids (yield: 92%) were collected by filtration and washed several times with methanol, which can be assigned to be palladacyclic dimers. Then, a Schlenk tube was charged with the above chloride-bridged palladacyclic dimers (0.5mmol), the corresponding imidazolium salt (1.25mmol) and tBuOK (2.5mmol) under nitrogen. Dry THF was added by a cannula and stirred at room temperature for 3h. The product was separated by passing through a short silica gel column with CH2Cl2 as eluent, the third band was collected and afforded the corresponding carbene adducts 3-10 as yellow solids. The characterization data for 3: Yield: 78%.
3-(1,3-bis(2,6-diisopropylphenyl)-1,3-dihydro-2H-imidazol-2-ylidene)-1-phenyl-3-(4-fluorophenyl)-1-phenylpropane-1,2-dione[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
67%
Stage #1: 1,3-bis[2,6-diisopropylphenyl]imidazolium chloride With potassium <i>tert</i>-butylate In tetrahydrofuran at 25℃; for 0.166667h; Inert atmosphere;
Stage #2: 4-fluorochalcone In tetrahydrofuran at 25℃; for 12h; Inert atmosphere;
Stage #3: In tetrahydrofuran for 2h;
With potassium carbonate; In tetrahydrofuran; at 65℃; for 16h;Inert atmosphere;
Tris [4- (pyridin-4-yl) phenyl] amine compound (47.6 mg, 0.10 mmol)1,3-bis (2,6-diisopropylphenyl) imidazolium chloride (IPr.HCl) (127.5 mg, 0.30 mmol),PdCl2 (53.2 mg, 0.30 mmol)And potassium carbonate (41.5 mg, 0.30 mmol) were added to a 25 mL single neck flask,Tetrahydrofuran (5 mL) was then added,The reaction was stirred at 65 C for 16 h under argon atmosphere.Stop the reaction,Cool to room temperature,concentrate,Thin layer chromatography to give compound I,Yield 57%.
[1,3-bis(2,6-diisopropylphenyl)imidazolium][Fe(PCy3)Cl3][ No CAS ]
Yield
Reaction Conditions
Operation in experiment
90%
Stage #1: iron(II) chloride; 1,3-bis[2,6-diisopropylphenyl]imidazolium chloride In tetrahydrofuran at 30℃; for 4h;
Stage #2: tricyclohexylphosphine In tetrahydrofuran at 30℃; for 6h;
3 Example 3: Synthesis of [Fe (PR3) X3] [(R1NCHnCHnNR1) CH] (R1 is 2,6-diisopropylphenyl, R is cyclohexyl, n is 1 and X is Cl)
takes the imidazole chlorine salt [(R 1 NCHCHNR 1) CH]Cl (0.42 g, 1.0 mmol) and the ferrous chloride (0.13 g, 1.0 mmol), in thf as the solvent, the 30 °C stirring for 4 hours. Centrifugal, supernatant fluid transfer, is added to the supernatant liquid of the three ring hexyl phosphine (0.28 g, 1.0 mmol), in 30 °C reaction under 6 hours. Vacuum to remove the solvent, hexane washing, drying, in a mixed solvent of toluene and tetrahydrofuran extraction, centrifugal supernatant fluid transfer, after concentrating the serum to obtain a target product, yield 90%.
[1,3-bis(2,6-diisopropylphenyl)imidazolium][Fe(PCy3)Br3][ No CAS ]
Yield
Reaction Conditions
Operation in experiment
85%
Stage #1: iron(II) bromide; 1,3-bis[2,6-diisopropylphenyl]imidazolium chloride With sodium bromide In tetrahydrofuran at 60℃; for 16h;
Stage #2: tricyclohexylphosphine In tetrahydrofuran at 30℃; for 6h;
4 Example 4: : Synthesis of [Fe (PR3) X3] [(R1NCHnCHnNR1) CH] (R1 is 2,6-diisopropylphenyl, R is cyclohexyl, n is 1 and X is Br))
taken the imidazole chlorine salt [(R 1 NCHCHNR 1) CH]Cl (0.42 g, 1.0 mmol), ferrous bromide (0.22 g, 1.0 mmol) and sodium bromide (0.33 g, 3.2 mmol), in thf as the solvent, the 60 °C reaction under 16 hours. Centrifugal, supernatant fluid transfer, remove precipitation, is added to the supernatant liquid of the three ring hexyl phosphine (0.28 g, 1.0 mmol), in 30 °C reaction under 6 hours. Vacuum to remove the solvent, hexane washing, drying, in a mixed solvent of toluene and tetrahydrofuran extraction, centrifugal supernatant fluid transfer, after concentrating the serum to obtain a target product, yield 85%.
With N-iodo-succinimide In dichloromethane at 40℃; for 3h; Sealed tube;
98%
With N-iodo-succinimide In dichloromethane at 40℃; for 2h; Inert atmosphere;
1 Example 1
The 250mL reaction flask was fully dried and filled with inert gas protection. Add 1,3-(2,6-diisopropylphenyl)imidazolium chloride (4.25g, 10mmol, 1.0equiv.), and add 100mL of anhydrous dichloromethane to dissolve it,Then N-iodosuccinimide (2.36g, 10.5mmol, 1.05equiv.) was added, and after stirring for 2 hours at 40°C,The reaction solution was washed with deionized water 50×3, the organic phases were combined, dried, and the solvent was removed under reduced pressure to obtain catalyst 1 as a pale yellow powder with a yield of 98%
With N-iodo-succinimide In dichloromethane at 40℃; for 2h;
12 Example 12
1,3-bis(2,6-diisopropylphenyl) imidazolium chloride salt (0.42g, 1mmol, 1.00eq.)* NIS(0.236g, 1.05 ol, 1.05eq.) was dissolved in dry dichloromethane (20mL) and stirred at 40°C for 2h. Cool down to the roomAfter warming, the mixture was washed with water (3 mL×4). Then remove the solvent by rotary evaporation under reduced pressure, wash with ethyl acetate and a small amount of acetone the light yellow Colored solid to obtain 1,3-bis-(2,6-diisopropylphenyl)-2-iodoimidazolium chloride in the form of a white solid (catalyst 1)
With potassium carbonate; In tetrahydrofuran; for 12h;Inert atmosphere; Reflux;
General procedure: Under an N2 atmosphere, a mixture of the imidazolium salt (1,3-bis(2,6-diisopropylphenyl)-1H-imidazol-3-ium chloride, 2.2 mmol), the required N-heterocycle (1.0 mmol), PdCl2(2.2 mmol) and K2CO3(2.2 mmol) was stirred in anhydrous THF (10 mL) under reflux for 12 h. After cooling, filtration and evaporation, the residue was purified by preparative TLC on silica gel plates, eluting with CH2Cl2 to afford the corresponding dinuclear N-heterocyclic carbene?palladium(II) complexes 1?4.
1,3-bis-(2,6-diisopropylphenyl)-2-iodo-imidazolium triflate[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
57%
Stage #1: 1,3-bis[2,6-diisopropylphenyl]imidazolium chloride With silver(l) oxide In dichloromethane; acetonitrile at 20℃; for 48h; Inert atmosphere;
Stage #2: With iodine In dichloromethane
Stage #3: sodium triflate In methanol; water
1.3.16 Synthesis of 1,3-Bis-(2,6-diisopropylphenyl)-2-iodo-imidazolium Triflate (C6-OTf)
Under inert atmosphere, 1,3-bis-(2,6-diisopropylphenyl)imidazolium chloride (1.03 g,1.86 mmol, 1.00 equiv.) was dissolved in dichloromethane/acetonitrile mixture (40 mL, 1:1 v/v)and silver(I) oxide (366 mg, 1.58 mmol, 0.85 equiv.) was added. The mixture was stirred at roomtemperature for 2 d and the solvent was removed in vacuum and the residue was treated withdichloromethane (20 mL) and not soluble material was filtered off. Then, iodine (802 mg,3.16 mmol, 1.70 equiv.) in dichloromethane (20 mL) was added slowly and stirred overnight andthe solvent was removed in vacuum. The crude intermediate, was dissolved in MeOH/H2O(150 mL, 1:2 v/v) and NaOTf (480 mg, 2.79 mmol, 1.50 equiv.) in MeOH/H2O (60 mL, 1:5 v/v)was added. More water (150 mL) was added to complete the precipitation. The solid was filteredoff and was recrystallized from CH2Cl2/MTBE to give C6-OTf (700 mg, 1.05 mmol, 57 %).
With water; oxygen; In dimethylsulfoxide-d6; at 150℃; for 155h;Sealed tube;Kinetics;
General procedure: Cu(I)-NHC 1a-g (0.04 mmol, 1.0 equiv) and CDCl3 (0.4 mL, degassed by bubbling argon for 30 min) were added into a flame-dried NMR tube. (CD3)2SO (0.4 mL) was used for 1h (0.04 mmol), 1i (0.02 mmol), and 1j (0.02 mmol). The NMR tube was closed with a septum and equipped with an air balloon (approximate 500 mL) containing approximately 100 mL of O2 (4.5 mmol, 112 equiv.) and approximately 12.6 mL of H2O (gas, 0.56 mmol, 14 equiv., air relative humidity = 75%). The solution (not agitated) was placed at room temperature and was monitored by 1H NMR. 100 C was used for the decomposition of 1h, and 150 C was used for the decomposition of 1i and 1j. The precipitate in the NMR tube was removed by quick filtration using a membrane filter before each 1H NMR measurement. The ratio of Cu-NHC, urea, and imidazolium were calculated through the integration of 1H NMR, using the normalization method. The characterization of products could be found in the previous study [32].
Stage #1: methanol; 1,2-bis(2,6-diisopropylphenylimino)ethane With sodium tetrahydroborate In tetrahydrofuran at 0 - 20℃; for 3h;
Stage #2: With ammonium chloride In tetrahydrofuran
1
Add 101.6g (0.27mol) of N, N'-bis (2,6-diisopropylphenyl) ethanediimide, 250mL of methanol, and 250mL of tetrahydrofuran to the reactor, and then reduce the temperature in batches below 0 Add 102 g (2.7 mol) of sodium borohydride and stir at room temperature for 3 hours. Then add the prepared saturated ammonium chloride solution until no white flocs appear. Then dichloromethane extraction and rotary evaporation to obtain the crude product, and then the filter cake was washed with 50mL of methanol and dried to a balanced weight to obtain the target product 1,3-bis (2,6-diisopropylphenyl) imidazolium chloride . The product is off-white solid, 65g, and the yield is 80%.
6 Example 6 Synthesis of complex Cu-5 (C27H36ClCuN2)
Add 850mg (2.0mmol) of ligand L5 to a 50mL flask,Copper phenylacetylene 363mg (2.2mmol), acetonitrile 20mL, in an oil bath at 70 ~ 80 ,The reaction was stirred for 12 hours, and the reaction mixture was cooled to room temperature and filtered.The filtrate was distilled under reduced pressure to remove the solvent to obtain 848 mg of colorless crystals with a yield of 87%.
Chemistry
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