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The first vinylsilylenes were isolated from photolysis of the corresponding trisilanes in 3-MP and 2-MeTHF matrices at 77 K. Contrary to the theoretical predictions, vinyl substitution caused a significant red shift of the n(Si)-3p(Si) transition of dimethylsilylene.

Tetrakis(trimethylsilyl)ethylene (1), tris(trimethylsilyl) (dimethylsilyl)ethylene and 1,2-bis(trimethylsilyl)-1,2-bis(dimethylsilyl)ethylene have been prepared and spectral properties are described. ESR spectra of anion and cation radicals of 1 are also recorded, indicating a nonplanar twisted structure for 1. These crowded olefins show interesting reversible thermochromism.

Three novel unsaturated spirocompounds with silicon as spiro atom(s) have been prepared. These constitute the first series of “polyspirene” and show interesting spectral properties.

Stereohomogeneous (E)- and (Z)-crotyltrifluorosilanes were prepared and used for the highly diastereoselective synthesis of threo- and erythro-β-methylhomoallyl alcohols, respectively, from aldehydes in the presence of fluoride ions. The mechanism of the reaction was discussed.

Various organotrifluorosilanes react with trimethylamine-N-oxide without catalyst to give the corresponding alcohols in high yields under mild conditions. Stereospecific nature of the reaction is suggestive of the involvment of intramolecular 1,2-organic-group migration from hypercoordinate silicon to oxygen.

Allyltrifluorosilane/CsF systems form pentacoordinate allylsiliconates which undergo chemoselective, regiospecific and highly stereoselective allylation of aldehydes, presumably via six-membered cyclic transition states.

Reduction of 1,1-bis(trimethylsilyl)ethylene by alkali metal led to the facile dimerization to the 1,1,4,4-tetrakis(trimethylsilyl)butane-1,4-diyl dianion which has been found to be utilized as a reagent for the Peterson reaction.