反应详情

In a 50 mL flask was placed amorphous silica gel (0.320 g; 200 m2/g, fully hydroxylated; previously activated in a 100° C. vacuum oven for 20 hrs). Monomeric salen ligand 5 (2.31 mL; as a 0.0411 M solution in 2:1 CH2Cl2/DMF, 0.095 mmol) was syringed on top of the silica. The sides of the flask were rinsed with 1 mL CH2Cl2 and the slurry was stirred under nitrogen at room temperature for 30 min. Vacuum was applied on the mixture to evaporate CH2Cl2 and most of the DMF, after which the flask was placed in a 100° C. oil bath under vacuum for overnight stirring under full vacuum. After 20 hrs, the contents of the flask were rinsed with CH2Cl2 and filtered through a glass frit, with sequential washes of CH2Cl2, MeOH and CH2Cl2. The solid was collected into a vial and dried in a vacuum oven at 50° C. for 48 hrs to give a bright yellow powder (0.345 g). The yellow filtrate was concentrated in vacuo to yield 0.034 g of a yellow oil, E; ligand concentration based on weight difference is calculated as 157 μmol/gsolid. Thermogravimetric analysis of a sample revealed a ligand concentration of 149 μmol/gsolid. Elem. anal. found (%): C, 7.1; N, 0.38. C/N wt % ratio calcd. for C44H68N2O6Si: 18.86. Found: 18.68.

1. customIn a 50 mL flask was placed amorphous
2. custompreviously activated in a 100° C.
3. customfor 20 hrs
4. washThe sides of the flask were rinsed with 1 mL CH2Cl2
5. customto evaporate CH2Cl2
6. customwas placed in a 100° C.
7. customfor overnight
8. stirringstirring under full vacuum
9. waitAfter 20 hrs
10. washthe contents of the flask were rinsed with CH2Cl2
11. filtrationfiltered through a glass frit, with sequential washes of CH2Cl2, MeOH and CH2Cl2
12. customThe solid was collected into a vial and
13. customdried in a vacuum oven at 50° C. for 48 hrs