Activation of the Si–Si σ-bond of 1,2-divinyldisilane catalyzed by Ru(II) complexes

In the presence of a catalytic amount of RuHCl(CO)(PR3)n (R=iPr, n=2; R=Ph, n=3), 1,1,2,2-tetramethyl-1,2-divinyldisilane (1) undergoes unexpected and clean isomerization via the Si–Si bond cleavage to yield a mixture of 6- and 5-membered cyclic compounds, 1,1,4,4-tetramethyl-1,4-disilacyclohex-2-ene and 1,1,2,3,3,-pentamethyl-1,3-disilacyclopent-4-ene, the former being the major product.