4-Alkyl-2,2,6,6-tetramethyl-1,4,2,6-oxaazadisilinanes: synthesis, structure, and conformational analysis
作者:Nataliya F. Lazareva、Bagrat A. Shainyan、Erich Kleinpeter
DOI:10.1002/poc.1605
日期:2010.1
Abstract4‐Alkyl‐2,2,6,6‐tetramethyl‐1,4,2,6‐oxaazadisilinanes RN[CH2Si(Me)2]2O [R = Me (1), i‐Pr (2)] were synthesized by two methods which provided good yields up to 84%. Low temperature NMR study of compounds (1) and (2) revealed a frozen ring inversion with the energy barriers of 8.5 and 7.7 kcal/mol at 163 and 143 K, respectively, which is substantially lower than that for their carbon analog, N‐methylmorpholine. DFT calculations performed on the example of molecule (1) showed that NMeax conformer to exist in the sofa conformation with the coplanar fragment CSiOSiC, and its NMeeq conformer in a flattened chair conformation. Copyright © 2009 John Wiley & Sons, Ltd.