Reactions of Stable N-Heterocyclic Silylenes with Ketones and 3,5-Di-tert-butyl-o-benzoquinone

The reactions of L [PhC(NtBu)2SiCl] and L′ [CH{(CCH2)(CMe)(2,6-iPr2C6H3N)2}Si] with monoketones and quinone have been examined. The reaction of L with 2-adamantanone furnishes a [1 + 2]–cycloaddition product 1, whereas with 3,5-di-tert-butyl-o-benzoquinone leads to the [1 + 4]–cycloaddition product 2. The treatment of L′ with 3,5-di-tert-butyl-o-benzoquinone gives [1 + 4]–cycloaddition product 3, and the reaction with acylferrocene yields compound 4. Compounds 1–4 were characterized by single crystal X-ray structural analysis, NMR spectroscopy, EI–MS spectrometry, and elemental analysis.