反应详情

A mixture of Fluka aluminum powder (20 g, 100-200 micron), Fluka aluminum granules (5 g, 0.15-1.7 mm), dry diethyl ether (200 mL), and iodine (2.0 g) was magnetically stirred under argon in a 3-neck 500 mL r.b. flask until the iodine color had disappeared. Mercury (20 g) was added, followed by chlorotrimethylsilane (120 mL, 945 mmole). The mixture was stirred at room temperature for 3 hr and lithium wire (Aldrich, 3.2 mm diam. - 0.01% Na, 1 mole, 7.0 g, 155 cm) was added in small pieces (0.3-0.5 cm). The stirred mixture was heated in an oil bath at 35°-40° C. for 48 hr. After allowing to cool, the mixture was filtered by suction through dry celite under argon directly in a r.b. flask. Complete transference was ensured by washing the reaction flask and filter funnel with dry diethyl ether and the combined filtrates were evaporated in vacuo. The residue was kept under high vacuum for 2 hr. Pentane (50 mL) was added and the mixture was swirled. After the solid had settled the solution was decanted via syringe and transferred to a new flask under argon. Another portion of pentane (50 mL) was added to the solid material and the procedure was repeated, combining the two pentane solutions. As the pentane solution of tris(trimethylsilyl)aluminum etherate is highly pyrophoric, all operations involving synthesis, storage, and use of the material were carried out under an inert atmosphere. The solution is indefinitely stable stored under argon in a freezer. The solution may be assayed by reaction with 1-formylcyclohexene, freshly prepared from 1-hydroxymethylcyclohexene by manganese dioxide oxidation. The aluminum reagent is added dropwise to 1.0 mmole of the aldehyde in dry diethyl ether (2 mL) under argon at -78° C. The transient red color with each drop no longer appears when the reaction is complete but the reaction is best monitored by thin layer chromatography, the starting material being readily visualized by UV while the product is not, even though the Rf s are similar. On a run following the procedure above, 0.67 mL of the aluminum reagent was required for the assay, indicating a concentration of 1.5N. This figure can be variable, however, depending on the batch of aluminum used and other factors.

1. stirringThe mixture was stirred at room temperature for 3 hr
2. temperatureThe stirred mixture was heated in an oil bath at 35°-40° C. for 48 hr
3. temperatureto cool
4. filtrationthe mixture was filtered by suction
5. customthrough dry celite under argon directly in a r.b
6. washby washing the reaction flask
7. filtrationfilter funnel with dry diethyl ether
8. customthe combined filtrates were evaporated in vacuo
9. additionPentane (50 mL) was added
10. customwas decanted via syringe
11. customtransferred to a new flask under argon
12. additionAnother portion of pentane (50 mL) was added to the solid material
13. customsynthesis, storage, and use of the material