The (C2H5)2AlCl/TiCl4 catalyst induces the [4+2] cycloaddition of butadiene or the [6+2] cycloaddition of 1,3,5-cycloheptatriene (CHT) to individual acetylenic moieties of 1,4-bis(trimethylsilyl)buta-1,3-diyne (BSD). Heating of the 2:1 butadiene adduct, bis(2-trimethylsilylcyclohexa-1,4-dien-1-yl), to 250 °C yields 2,2'-bis(trimethylsilyl)biphenyl. The 1:1 adduct of BSD with CHT, 7-trimethylsilyl-8-trimethylsilylethynylbicyclo[4.2.1]nona-2,4-diene, is obtained as virtually the only product if the initial molar ratio CHT : BD equal to 1.86 is used.

The catalytic system Et2AlCl/TiCl4 induces Diels-Alder addition of phenyl(trimethylsilyl)acetylene (PTMSA) to 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-methyl-1,3-pentadiene, and [6+21 addition of PTMSA to 1,3,5-cycloheptatriene. The 1-phenyl-2-(trimethylsilyl)-cyclohexa-1,4-dienes obtained undergo thermolysis, yielding the corresponding ortho-(trimethylsilyl)biphenyl derivatives. The cyclohexadienes containing vicinal methyl and trimethylsilyl groups evolve methane at 300°C (the 3-methyl group is released). All other derivatives release hydrogen at only 260°C.