new biodegradable network polymers containing siloxane-linked polymeric prodrugs of 5-ammino-2-hydroxybenzoic acid (5-asa) in the main chain were prepared by ter polymerization of methacrylic acid (ma), 2-hydroxyethylmethacrylate (hema), and bis (trimethylsilyloxy) methylsilane (vbm) in the presence of some new cross-linking agents.the monomers and polymers were characterized by ft-ir and 1h-nm...

Part I: The synthesis of 2-vinylindole, the parent of 2-alkenylindoles, has been achieved in three steps (70-76% yield) based on a novel allene cyclization developed in our laboratory. 2-Alkenylindoles have found use as precursors to indole and carbazole alkaloids via the Diels-Alder reaction. The key step of the synthesis involves isomerization of an arylacetylenecarbamate to an arylallenecarb...

A new hydrogel based on vinylsilane-chitosan and acrylamide was synthesized as VSi-CTS-g-PAAm used to remove methylene blue (MB) from aqueous solution using batch adsorption technique. The VSi-CTS-PAAm interacted with dye at different mass-liquid ratios, pH, temperature. amount of MB removal estimated a UV-Vis spectrophotometer an optical density λmax= 665 nm. most effective pH 12, about 98 % 5...

Hydrosilylation of acetylene with a chiral silane, R-(+)-methyl-1-naphthylphenylsilane [R-(+)-MeNpPhSi*H], in the presence of H2PtCl6·xH2O proceeds with retention of the configuration of the stereogenic silicon center and produces a chiral vinylsilane or silylethylene [S-(+)-MeNpPhSi*Vi] of high optical purity under mild conditions (50°C) in high chemical yield (85%). Anionic polymerizations of...

The β-Z selectivity in the hydrosilylation of terminal alkynes has been hitherto explained by introduction of isomerisation steps in classical mechanisms. DFT calculations and experimental observations on the system [M(I)2{κ-C,C,O,O-(bis-NHC)}]BF4 (M=Ir (3a), Rh (3b); bis-NHC=methylenebis(N-2-methoxyethyl)imidazole-2-ylidene) support a new mechanism, alternative to classical postulations, based...