Thermolysis of Cp(2)Ti(CH(2)SiMe(3))(2) in the presence of Me(3)SiC=CSiMe(3) forms tris(trimethylsilyl) titanacyclobutene. Unlike other titanacyclobutenes which undergo insertion with carbonyl compounds, this reagent serves as a precursor to Cp(2)Ti=CHSiMe(3), converting carbonyl compounds to the corresponding alkenyl silanes. This olefination takes place under mild conditions even at room temperature and works with aldehydes, ketones, esters, thioesters and lactones.