Synthesis of 4‑Silacyclohexan-1-ones and (4-Silacyclohexan-1-yl)amines Containing the Silicon Protecting Groups MOP (4-Methoxyphenyl), DMOP (2,4-Dimethoxyphenyl), or TMOP (2,4,6-Trimethoxyphenyl): Versatile Si- and C‑Functional Building Blocks for Synthesis

The
4-silacyclohexanones 1–6 were
prepared in convenient multistep syntheses, starting from MeSi­(OMe)3 and PhSi­(OMe)3, respectively. Cleavage of the
4-methoxyphenyl (MOP), 2,6-dimethoxyphenyl (DMOP), and 2,4,6-trimethoxyphenyl
(TMOP) protecting groups of 4–6 by
treatment with HCl/Et2O in CH2Cl2 at 20 °C gives the 4-chloro-4-silacyclohexanone 13. Reductive amination of 1–6 with
NH3 or i-PrNH2 yields the respective
(4-silacyclohexan-1-yl)­amines 7–12. Compounds 1–12 and all new precursors
synthesized were characterized by elemental analyses (C, H, N) or
mass spectrometric investigations (ESI-HRMS) and by NMR spectroscopic
studies (1H, 13C, 29Si). Compounds 1, 3, 5, and 6 and
the precursors (MeO)2SiPh­(TMOP) (21) and (CH2CH)2SiPh­(TMOP) (27) were additionally
characterized by single-crystal X-ray diffraction. Compounds 1–12 with their Si- and C-functional groups
represent versatile building blocks for synthesis.