反应详情

4-Iodo-2-methyl-1H-imidazole (1.0 g, 4.8 mmol) was dissolved in 30 mL of THF. Copper TMEDA catalyst (447 mg, 0.96 mmol, Aldrich) and then phenylboronic acid (0.41 g, 3.35 mmol) were added. Oxygen gas was bubbled into the reaction mixture for 20 min, then the mixture was stirred at room temperature for 90 min. An additional 0.21 g of phenylboronic acid was added followed by an additional 20 min of oxygen gas bubbling and 75 min of stirring at room temperature. An additional 0.21 g of phenylboronic acid was added followed by an additional 20 min of oxygen gas bubbling and then stirring at room temperature for 20 h. The reaction mixture was filtered through a bed of neutral alumina, concentrated and purified by silica gel chromatography (ethyl acetate/hexanes) to give 0.55 g (40%) of 4-iodo-2-methyl-1-phenyl-1H-imidazole ((M+H)+=285) and 0.47 g (35%) of 5-iodo-2-methyl-1-phenyl-1H-imidazole.

1. customOxygen gas was bubbled into the reaction mixture for 20 min
2. additionAn additional 0.21 g of phenylboronic acid was added
3. waitfollowed by an additional 20 min of oxygen gas
4. custombubbling and 75 min
5. stirringof stirring at room temperature
6. additionAn additional 0.21 g of phenylboronic acid was added
7. waitfollowed by an additional 20 min of oxygen gas
8. custombubbling
9. stirringstirring at room temperature for 20 h
10. filtrationThe reaction mixture was filtered through a bed of neutral alumina
11. concentrationconcentrated
12. custompurified by silica gel chromatography (ethyl acetate/hexanes)