TY  - JOUR
A1  - Kirpichenko, Svetlana V.
A1  - Shainyan, Bagrat A.
A1  - Kleinpeter, Erich
T1  - Unusual conformational preferences of 1,3-dimethyl-3-isopropoxy-3-silapiperidine
T2  - Journal of physical organic chemistry
N2  - The conformational analysis of the first representative of the Si-alkoxy substituted six-membered Si,N-heterocycles, 1,3-dimethyl-3-isopropoxy-3-silapiperidine, was performed by low-temperature 1H and 13C NMR spectroscopy and DFT theoretical calculations. In contrast to the expectations from the conformational energies of methyl and alkoxy substituents, the Meaxi-PrOeq conformer was found to predominate in the conformational equilibrium in the ratio Meaxi-PrOeq : Meeqi-PrOax of ca. 2 : 1 as from the 1H and 13C NMR study. The thermodynamic parameters obtained by the complete line shape analysis showed that the main contribution to the barrier to ring inversion originates from the entropy term of the free energy of activation.
KW  - barrier to ring inversion
KW  - conformational equilibrium
KW  - DFT theoretical calculations
KW  - dynamic NMR
KW  - silapiperidines
Y1  - 2012
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/35471
SN  - 0894-3230
VL  - 25
IS  - 12
SP  - 1321
EP  - 1327
PB  - Wiley-Blackwell
CY  - Hoboken
ER  -