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The intramolecular dehydrogenative cyclization of 2-(dialkylsilyl) biaryls proceeded in the presence of a catalytic amount of platinum(II) chloride and potassium tris(3,5-dimethyl-1- pyrazolyl)borohydride to give good yields of the corresponding dibenzosilole derivatives. [ABSTRACT FROM AUTHOR]

Highly selective photocyclic aromatization (SCAT) of poly(substituted acetylene)s, which can quantitatively yield the corresponding 1,3,5-trisubstituted benzene derivative, was applied to quantitative determination of the microstructures of copoly(substituted acetylene)s. By GPC analysisof the SCAT products of the copolymers of two substituted acetylenes having substituents whose molecular weights were greatly different, some clear information regarding the microstructures, such as sequence (triad) distribution and composition, which could not be obtained from NMR because of their broad peaks, could be obtained successfully under a mild condition. [ABSTRACT FROM AUTHOR]

An amphiphilic 1,3,5-trisubstituted benzene as a new 2D surface modifier (T-EO) which has six hydroxy groups and three oligoethylene groups was successfully and easily synthesized by selective photocyclic aromatization in high conversion and selectivity for the first time. We prepared four kinds of blend membranes based on PVA or poly(trimethylsilylphenylacetylene) (poly(SPA)) containing the new amphiphilic cyclic trimer (T-EO) or the corresponding polymer (P-EO), that is, T-EO/PVA, P-EO/PVA, and T-EO/poly(SPA) membranes prepared by conventional solvent casting method (Method I) and T-EO/poly(SPA) membranes prepared by a new solvent casting method (Method II). T-EO/PVA membranes by Method I and T-EO/poly(SPA) membranes by Method II showed better performance in oxygen permeation than P-EO/PVA membranes by Method I and T-EO/poly(SPA) membranes by Method I, respectively. A PVA-based membrane containing 1.0 wt% T-EO showed the best performance, that is, the α became twice that of the original PVA membrane without any decrease in PO2. The ideal improvement may be caused by effective surface modification by T-EO. [ABSTRACT FROM AUTHOR]

The intermolecular dehydrogenative coupling of 1,1,1,3,5,5,5-heptamethyltrisiloxane with aromatic compounds such as aryloxazolines and arylimines in the presence of a catalytic amount of [RuCl2 (p-cymene)] 2 gave the corresponding orthosilylated products in good yields. [ABSTRACT FROM AUTHOR]

A new polymer prepared by polymerization of 3,5-bis-(hydroxymethyl)phenylacetylene having a chiral menthyl group via a very long and rigid spacer by an achiral rhodium complex with triethylamine as an initiator showed strong CD absorptions assigned to the main chain in spite of the long distance (23¡) between the chiral group and the polymerizing group in the monomer. This distance is the longest to the best of our knowledge. In addition, switching between the two chiralities of the resulting polymer was realized in the CD spectrum. [ABSTRACT FROM AUTHOR]