Disulfuration and hydrosulfuration of an alkyne at a 1,2-dicarba-closo-dodecaborane-thiolate ligand.

The reaction of the dinuclear cobalt compound [(CpCoS(2)C(2)B(10)H(10))(CpCoSC(2)B(10)H(11))(n-C(4)H(9)S)] (1) with HC≡CC(O)Fc leads to the cobalt-free products (C(2)B(10)H(10))(SCH=CHCOFc)(2) (4-6), (S(2)C(2)B(10)H(10))(HC=CCOFc) (7), and (C(2)B(10)H(11))(SCH=CHCOFc) (8, 9). 4-6 are produced by hydrosulfuration of the alkyne at the 1,2-dicarba-closo-dodecaborane-dithiolate ligand with the generated vinyl groups in Z/Z, Z/E and E/E configurations, respectively. In 7, the alkyne is added to 1,2-dicarba-closo-dodecaborane-dithiolate at the two sulfur sites. 8 and 9 are the products of alkyne hydrosulfuration at the 1,2-dicarba-closo-dodecaborane-1-monothiolate ligand with the generated vinyl group in either Z or E configuration. The treatment of 1 with HC≡CCO(2)Me gives rise to the parallel products (C(2)B(10)H(10))(SCH=CHCO(2)Me)(2) (10-12) and (C(2)B(10)H(11))(SCH=CHCO(2)Me) (13, 14). All of the new compounds have been characterized by IR, NMR, elemental analysis and mass spectroscopy. The structures of compounds 4, 7, and 8 have also been determined by single-crystal X-ray diffraction analysis.