sequential reactions using silyl group-substituted titanium carbene complexes was studied. Dienylsilanes were obtained by the olefination of carbonyl compounds with γ-silylvinylcarbene complexes. Cyclopropanation of 1-alkenes with the vinylcarbene complexes produced (E)-(β-silylvinyl)cyclopropanes with high stereoselectivity. The reaction of β-(trialkylsilyl)carbene complexes with zinc alkoxides of homopropargyl
Titanocene alkylidene complexes, generated by desulfurizative titanation of thioacetals with Cp2Ti[P(OEt)3]2, reacted with alkynyl methyl sulfones to produce organotitanium species, which gave tert-homopropargyl alcohols with high diastereoselectivity on treatment with aromatic and alpha,beta-unsaturated ketones.
Titanocene(II)-promoted reaction of anilides with thioacetals followed by treatment with a small amount of water gave reductivealkylation products, anilines with a secondary alkyl group.
Titanocene(II)-promoted olefination of various carbonyl compounds using 1,1-bis(phenylthio)-2-triorganosilylethanes gave allylsilanes in good yields. γ-Alkoxy and alkylthio group substituted allylsilanes were also obtained by using carboxylic esters and thiolesters, respectively.