FLUOROSILYL(PYRROLYL)SILYLAMINES AS PRECURSORS FOR INTRAMOLECULARLY AND INTERMOLECULARLY STABILIZED IMINOSILANES

Three indolyl- and pyrrolylsilylamines 1-3 were prepared from lithiate d heterocyclics and fluorosilylamines. Further reaction with di-tert-b utyldifluorosilane led to the fluorosilylpyrrolylsilylamines 4 and 5. The fluorosilylpyrrolylsilylamine 6 was prepared by reaction of bis(fl uorodiisopropylsilyl)amine and lithium pyrrolide. Lithiiation with n-b utyllithium of 4-6 solved in THF gave the iminosilane-LiF adducts 7-9; in contrast, lithiation of 5 in n-hexane led to the lithium fluorosil ylamid 10. Heating of the iminosilane-LiF adduct 7 gave the bicyclic s ystem 11, an intramolecularly stabilized iminosilane. Addition of chlo rotrimethylsilane to 9 led to fluorine-chlorine exchange and eliminati on of lithium chloride. The product is the intermolecular stabilizatio n of the intermediate iminosilane as a four-membered ring 12. The X-ra y structures of 1, 11 and 12 have been determined.