Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1324317 | Journal of Organometallic Chemistry | 2014 | 12 Pages |
•S⋯Si and S⋯Sn interactions stabilize 2-SiR3- and 2-SnR3 derivatives of 5-alkyl-[1,3,5]-dithiazinanes.•New [1,3,5]-dithiazinanes with bulky organometallic substituents.•29Si and 119Sn NMR, X-ray diffraction and calculations determined the preferred conformation in dithiazinanes.
A series of 2-R3′E (E = Si or Sn; R′ = Me or Ph) derivatives of 5-R-[1,3,5]-dithiazinanes (R = Me, iPr, tBu) are reported, as well as some of their N–BH3 adducts. Structures were determined by 29Si, 119Sn, 11B, 13C and 1H NMR and X ray diffraction analyses. Minimum energy conformations were calculated by HF/6-31++G(d,p) and B3LYP/6-31++G(d,p) methods. Preferred conformations and steric and stereoelectronic interactions are analyzed. In the solid state the ring conformation is a chair with the N–R group in axial and the 2-substituents in equatorial position. The Si or Sn atoms linked to C-2 have short distances to the two sulfur atoms, interpreted as Si⋯S and Sn⋯S stabilizing contacts. The 119Sn NMR chemical shifts and 1J(13C,119Sn) coupling constants evidenced weak S⋯Sn coordination bonds. Substitution reactions at C2 performed in N–BH3 adducts of 2-lithium-5-methyl-[1,3,5]-dithiazinanes of anchored conformation proceed with retention of C2 configuration.
Graphical abstract2 – R′3E (E = Si or Sn; R′ = Me or Ph) derivatives of 5-R-[1,3,5]-dithiazinanes (R = Me, iPr, tBu) are reported. Structures were determined by NMR, X-ray diffraction and calculations. The Si or Sn atoms have short distances to sulfur atoms, interpreted as Si⋯S and Sn⋯S stabilizing contacts.Figure optionsDownload full-size imageDownload as PowerPoint slide