An original family of well-defined molecular and macromolecular double-decker silsesquioxane derivatives with ethyl bridged π-conjugated arenes is obtained via hydrosilylation reaction.

Vinyl-substituted germanes react stereo- and regioselectively with olefins in the presence of complexes containing Ru-H and Ru-Ge bonds with the formation of functionalized vinylgermanes that cannot be synthesized by olefin cross-metathesis procedures. The reaction opens a new catalytic route for preparation of a class of organogermanes that are potent organometallic reagents for organic synthesis because they show very low toxicity and could replace organotin compounds. The mechanism of this new catalytic route was proven to involve an interesting insertion of the vinylgermane into the Ru-H bond and beta-Ge transfer to the metal with elimination of ethylene and generation of an Ru-Ge bond, followed by insertion of the alkene into the Ru-Ge bond and beta-H transfer to the metal to eliminate the substituted vinylgermane.

No abstract

An efficient synthetic route for well-defined palladium(0) complexes [Pd(η(2)-dba)(PPh3)2] (2), [Pd(η(2)-dba)(PCy3)2] (3) and their crystallographic structures is reported. This is the first crystallographic characterization of palladium complexes coordinated with one dibenzylideneacetone and two phosphines. A highly effective, fully controlled method for selective synthesis of mono- (5-9) and distyrylarenes (10-15) via Suzuki-Miyaura coupling is described.

No abstract

No abstract

No abstract

The highly stereo- and regioselective reaction of 1,3,5-tris(dimethylvinylsilyl)benzene (1) with p-substituted styrenes, p-XC6H4CHCH2, where X = H (2), Cl (3), Br (4), vinyl (5), catalyzed by RuHCl(CO)(PCy3)2 (I) appeared to be an efficient basis for new starburst compounds involving silylene−vinylene−arylene sequences. Attempts were made to synthesize the first generation of dendrimer (12), based on 1 as a core, via two methods:  direct silylative coupling of 1,3,5-tris[dimethyl(4-vinylstyryl)silyl]benzene (5) with 1, which gave a mixture of oligomers containing the SiCHCHSi structure, and successfully via silylation of 5 with vinylsilyl-3,5-bis(isopropoxysilyl)benzene (10) followed by vinylation with Grignard reagent. Additionally, the double silylation of DVB with 10 followed by vinylation allowed the synthesis of an analogous starburst compound (14), which can be a new core for analogous dendritic compounds.