Long-chain alkanes with an internal -H2Si-SiH2-linkage

Article abstract of DOI:10.1016/0022-328X(96)06391-7

1,2-Bis(p-tolyl)disilane (2) has been prepared through Wurtz-coupling of chloro(p-tolyl)silane using lithium metal. It was used as a precursor for 1,2-bis(trifluoromethanesulfonyloxy)disilane (1), which was obtained by treatment with two equivalents of trifluoromethanesulfonic acid. This intermediate was treated with n-BuLi, n-HexLi or n-OctMgBr to give the title compounds (n-C_nH_2n+1)SiH₂-SiH₂(n-C_nH_2n+1) (n = 4,6,8), 4a-c. Treatment of 2 with only one equivalent of triflic acid gave p-TolSiH₂SiH₂OSO₂CF₃ (5), which can be selectively converted into mixed alkyl-aryl-disilanes with LiR reagents, e.g. (n-Bu)SiH₂SiH₂(p-Tol), 6. The crystal structure of compound 2 has been determined by an X-ray diffraction study; it has a staggered trans-conformation with a crystallographic center of inversion.