TITANIUM-CATALYZED DIELS-ALDER CYCLOADDITION OF CONJUGATED DIENES TO BIS(TRIMETHYLSILYL)ACETYLENE. 1,2-BIS(TRIMETHYLSILYL)CYCLOHEXA-1,4-DIENE, 1,2-BIS(TRIMETHYLSILYL)BENZENE, AND THEIR METHYL DERIVATIVES

Article abstract of DOI:10.1016/0022-328X(85)87410-6

The catalytic system Et2AlCl/TiCl4 induces Diels-Alder cycloaddition of bis(trimethylsilyl)acetylene to 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene and (E)-1,3-pentadiene affording 1,2-bis(trimethylsilyl)cyclohexa-1,4-dienes in high yields.The cyclohexadienes are readily converted to the corresponding 1,2-bis(trimethylsilyl)benzenes upon heating to 240 deg C.Mass, infrared, 1H, 13C and 29Si NMR spectra of all the products obtained are reported and briefly discussed.The crowded character of aromatic compounds is reflected in their mass, 13C and 29Si NMR spectra.