Thermal behavior of benzobis(tetraethyldisilacyclobutene)

The thermolysis of benzo[1,2:4,5]bis(1,1,2, 2-tetraethyl-1,2-disilacyclobut-3-ene) (1) in the presence of ethylene in an autoclave at 250 °C for 24 h afforded two products, compound 2, consisting of one molecule of 1 and two ethylene molecules, and compound 3, arising from two molecules of 1 and three molecules of ethylene in 60 and 20 % yields, respectively. The reaction of 1 with phenylacetylene at 150 °C for 24 h gave a mixture of regioisomers 4a and 4b, arising from the insertion of the triple bond of phenylacetylene into two silicon-silicon bonds in 1 in 86 % combined yield. The reaction of 1 with 1-hexyne at 150 °C for 24 h again produced two regio-isomers 5a and 5b in 85 % combined yield.