16117-15-0Relevant academic research and scientific papers
Asymmetric allylation polymerization of bis(allylsilane) and dialdehyde containing Si-phenyl linkage
Kumagai, Toshihiro,Itsuno, Shinichi
, p. 2509 - 2516 (2007/10/03)
Repetitive Sakurai-Hosomi allylation between dialdehyde and bis(allylsilane) yielded a polymer having stereogenic carbons in its main chain. In the presence of an enantiopure Lewis acid catalyst such as chiral (acyloxy)borane (CAB), the allylation polymerization proceeded in a stereoselective manner to give optically active polymers. We have prepared new monomers containing Si-phenyl linkages for the asymmetric allylation polymerization. After polymerization, the Si-phenyl linkages in the main chain could be cleaved easily to give the corresponding chiral homoallylic alcohol. The enantiomeric purity of the chiral polymer was then evaluated by chiral HPLC analysis of the alcohol obtained from the degradation.
Transmission of electronic effects via a SiMe2 spacer in 4-mono- and 4,4'-disubstituted diphenyldimethylsilanes: 29Si and 13C NMR spectroscopy and PM3 semi-empirical calculations
Walree, Cornelis A. van,Lauteslager, Xavier Y.,Wageningen, Andreas M. A. van,Zwikker, Jan W.,Jenneskens, Leonardus W.
, p. 117 - 126 (2007/10/02)
Some 29Si and 13C NMR studies were performed of series of 4-substituted phenyltrimethylsilanes and 4-substituted and 4,4'-disubstituted diphenyldimethylsilanes.Within each series linear relationships are found between the chemical shifts and (a) the Hammett substituent constants ?p and (b) the PM3-calculated total atomic charges.It is inferred that the SiMe2 ?-type spacer weakly mediates substituent effects in the ground state via a bond polarization mechanism.A comparison with available data for 4-substituted and 4,4'-disubstituted diphenylmethanes shows that the SiMe2 group is a better transmitter of electronic effects that the CH2 group. Keywords: Silicon; 29Si NMR; 13C NMR; Substituent effects; MO calculations
