Stereochemistry of 3-isopropoxy-3-methyl-1,3-oxasilinane-the first 3-silatetrahydropyran with an exo-cyclic RO-Si bond
- Molecular structure and conformational behavior of 3-isopropoxy-3-methyl-3-oxasilinane is studied by low temperature C-13 NMR spectroscopy and theoretical calculations (DFT, MP2). Two conformers, 1-ROax and 1-ROeq, were found experimentally and located on the potential energy surface. LT C-13 NMR spectroscopy gives almost equal population of the two conformers at 98 K with Delta G(98K)degrees=0.02 kcal/mol in favor of 1-ROax and Delta G(98K)(#)=4.5 kcal/mol. The corresponding DFT calculated values (Delta G(98K)degrees=0.03 kcal/mol, Delta G(98K)(#)=5.1 kcal/mol) are in excellent agreement with the experiment. Detailed DFT and MP2 calculations of the solvent effect on the conformational equilibrium were performed and highlighted the leveling out of the two conformers when transferred from gas to solution. (C) 2015 Published by Elsevier Ltd.
Author details: | Bagrat A. Shainyan, Svetlana V. Kirpichenko, Erich KleinpeterORCiDGND |
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DOI: | https://doi.org/10.1016/j.tet.2015.07.047 |
ISSN: | 0040-4020 |
Title of parent work (English): | Tetrahedron |
Publisher: | Elsevier |
Place of publishing: | Oxford |
Publication type: | Article |
Language: | English |
Year of first publication: | 2015 |
Publication year: | 2015 |
Release date: | 2017/03/27 |
Tag: | 1,3-Oxasilinanes; Assignment of stereochemistry; Barrier to ring inversion; Conformational equilibrium; Solvent effects |
Volume: | 71 |
Issue: | 38 |
Number of pages: | 7 |
First page: | 6720 |
Last Page: | 6726 |
Funding institution: | Russian Foundation for Basic Research [14-03-00923] |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Chemie |
Peer review: | Referiert |