Silsesquioxane chiral

Keywords bridged silsesquioxanes, chirality, self-assembly... 

In the context of asymmetric catalysis, titanium silsesquioxanes containing the chiral ligand (lR,2S,5R)-(-)-menthoxo ligand (MentO) (figure 14.3) have been synthesized from the monosilanol la (R = cyclopentyl) and Ti(OPr )4 [70]. The molecular complexes were tested as asymmetric homogeneous catalysts for the epoxidation of cinammic alcohol with tert-butyl hydroperoxide and compared... 

Chiral organic-inorganic hybrid materials such as silsesquioxane and ephedrine immobilized on silica gel also act as chiral inducers of asymmetric autocatalysis (Scheme 24) [124-126]. Enantioselective addition of z-Pr2Zn... 

I.M. Saez, J.W. Goodby, R.M. Richardson, A liquid crystalline silsesquioxane dendrimer exhibiting chiral nematic and columnar mesophases. Chem. Eur. J. 7, 2758-2764 (2001)... 

For the synthesis of chiral diazaphos-pholidine terminated polyhedral oligomeric silsesquioxanes and their application in the asymmetric hydro-formylation of vinyl acetate, compare Vautravers, N.R. and Cole-Hamilton, D.J. (2009) Chem. Commun., 92-94. 

The synthesis and properties of star polymers and dendrimers functionalized with ferrocene units has attracted a great deal of attention. The synthesis of high-generation dendrimers functionalized with chiral ferrocenyl units in their structures has been reported. The chiroptical properties of this class of dendrimer was dependent on the number of ferrocenyl groups and their chemical environment, but not on their position within the dendrimer. Deschenaux has reported the synthesis of hquid crystalline ferrocene-based polymers prossessing an enantiotropic smectic A phase. Ferrocene-functionahzed cyclic siloxane (29) and silsesquioxane branched polymers have also been reported. A hyperbranched polymer with a cubic silsesquioxane core was used to mediate the electrocatalytic oxidation of ascorbic acid. 

Kawasaki, T., Ishikawa, K., Sekibata, H., Sato, 1., and Soai, K. (2004) Enantioselective synthesis induced by chiral organic-inorganic hybrid silsesquioxane in conjunction with asymmetric autocatalysis. Tetrahedron Lett, 45, 7939-7941. 

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