反应详情

General procedure for coupling reactions using 2-pyridin-2-yl-1H-benzoimidazole (L2): (E)-4-((2-(Phenoxy) vinyl)oxy)-1,1′-biphenyl (5): An oven dried, three-necked, round-bottomed flask (50 mL) equipped with a nitrogen inlet, reflux condenser, rubber septum was repeatedly evacuated and back-filled with dry and pure nitrogen, and was then charged with CuI (0.074 g, 0.39 mmol, 0.5 eq), L2 (0.076 g, 0.39 mmol, 0.5 eq) and Cs2CO3 (0.63 g, 2.0 mmol, 2.5 eq), followed by addition of DMF (2 mL). The solution was stirred for 10 min at rt until reaction turn light green color. The appropriate substrate phenol (0.073 g, 0.78 mmol, 1 eq) was added to the reaction mixture and then stirred for addition 5 min at rt. Compound 4 (0.25 g, 0.78 mmol, 1 eq) was dissolved in minimum amount of solvent and then added into the reaction mixture. The reaction mixture was then heated from rt to between 50-75° C. for 12-36 h depending on the substrate. The reaction mixture was cooled and then through pad of silica gel using ethyl acetate and hexane mixture (20:80, 100 mL) and then washed three times with the same solvent mixture (100 mL). Filtrate was washed with water (100 mL×3) followed with brine (200 mL), dried using anhydrous sodium sulfate and concentrated in vacuo to yield brown oil. The crude oil was then purified by silica gel column chromatography using 100% hexane to afford 5 as white crystals. (0.18 g, 70%): mp 60-63° C. 1H NMR (300 MHz, CDCl3): 7.59-7.54 (m, 4H, HAr), 7.47-7.40 (m, 2H, HAr), 7.37-7.31 (m, 1H, HAr), 7.16-7.03 (m, 7H), 6.92 (s, 2H, HC═CH); 13C NMR (75 MHz, CDCl3): 157.6, 157.2, 140.4, 135.8, 134.9, 134.6, 129.7, 128.8, 128.4, 127.0, 126.9, 122.7, 116.0, 115.8; IR (cm−1): 3061, 2962, 2870, 1606, 1510, 1485, 1419, 1365, 1230, 1183, 1174, 1124, 1105, 1006, 896, 836, 728; HRMS (ESI), Calculated for C20H16O2 [M−H]− 287.1072. Found 287.1053; HPLC analysis: 91% purity.

1. dry with material(E)-4-((2-(Phenoxy) vinyl)oxy)-1,1′-biphenyl (5): An oven dried
2. customthree-necked, round-bottomed flask (50 mL) equipped with a nitrogen inlet
3. temperaturereflux condenser
4. customrubber septum was repeatedly evacuated
5. additionback-filled
6. customwith dry
7. stirringstirred for addition 5 min at rt
8. additionadded into the reaction mixture
9. temperatureThe reaction mixture was then heated from rt to between 50-75° C. for 12-36 h
10. temperatureThe reaction mixture was cooled
11. washwashed three times with the same solvent mixture (100 mL)
12. washFiltrate was washed with water (100 mL×3)
13. customdried
14. concentrationconcentrated in vacuo
15. customto yield brown oil
16. customThe crude oil was then purified by silica gel column chromatography