1 -octenyl silane

The silanized surfaces were characterized by DRIFT ( ffiise reflectance infrared jfourier fransform) spectroscopy [1, 2], Fig. 2-4 show the DRIFT-spectra of untreated silica gel and the analogous substrate after application of l-octenyl-8-dimethylethoxysilane or of the copolymer. 

To our surprise, however, ( )-l-octenyl(trifluoro)silane (n = 3) did not give the coupled product to any extent. We assumed in this case an unreactive hexacoordinate silicate was preferentially produced by the reaction with 2 mol of TASF, whereas with the mono- or difluorosilane, coordinatively unsaturated pentacoordinate silicate was assumed to be produced and underwent transmetallation effectively. Therefore, we considered that the transmetallation proceeded through a four-centered transition state, wherein silicon should be hexacoordinated [Eq.(8)]. The corresponding hexacoordinated silicate had to liberate one fluoride ion to be incorporated into the transmetallation. 

Some vinyl silanes were found to act feasibly as weakly interacting comonomers. Functional copolymers with ethylene and vinyl-Si(CH3)3, aUyl-Si(CH3)3,3-butenyl-Si(CH3)3, 4-pentenyl-Si(CH3)3, 5-hexenyl-Si(CH3)3 or 7-octenyl-Si(CH3)2Ph as comonomers were polymerized [23-25]. The short trialkylsilane monomers suffered from the electroific influence of sihcon, which led to poor polymerization performance. In these cases, the chain end of the S3mthesized polyethylene-co-allyl-Si (CH3)3 consisted of reactive allyhc silane groups and therefore the functionality and reactivity of these copolymers was higher than the weakly interacting trimethylsUane moiety can provide. Also it was found that the phenylene group in... 

To a solution of 4-trifluoromethyliodobenzene (136 mg, 0.50 mmol) and ( )-dimethyl(l-octenyl)(2-thienyl)silane (151 mg, 0.60 mmol) in THF are added a 1-M solution of TBAF (1.20 mL, 1.20 mmol) in THF and Pd(OAc)2 (5.6 mg, 25 pmol) at rt. The mixture is stirred at rt for 1 h, poured into saturated NaHCOs aq., and extracted with ethyl acetate. The combined organic layers are washed with brine and dried over Mg2S04. Removal of the solvent under reduced pressure followed by column chromatography on silica gel (hexane-ethyl acetate = 50 1) gives the title compound in cross-coupled product quantitatively. ... 

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