Preparation of alka-2,4-dienylsilanes and 3-cyclopropylprop-2-enylsilanes by the titanocene(II)-promoted reaction of 2,4-bis(phenylthio)but-3-enylsilanes

Preparation of allylsilanes by the Cp2Ti[P(OEt)3]2 (1)-promoted reaction of 2,4-bis(phenylthio)but-3-enylsilanes 5 is described. The olefination of carbonyl compounds 6 using the silanes 5 and the low-valent titanium species 1 produced alka-2,4-dienylsilanes 2. 3-Cyclopropylprop-2-enylsilanes 3 were obtained by the reaction of 5 with 1 in the presence of terminal olefins 9.