Synthesis of 1,10-disulfanyl-<i>closo</i>-decaborate anion and its tetraacetylamidedisulfonium derivative

A method has been proposed for the preparation of 1,10-disulfanyl-closo-decaborate anion [1,10-B10H8(SH)2]2-(3). This compound can be easily prepared in several steps. The first stage consists of selective introduction of the zwitterion of iodine at the apical vertices into the closo-decaborate anion (1,10-B10H8(IPh)2(1)). At the second stage, this group is replaced by thiodimethylformamide (1,10-B10H8(SCHNMe2)2(2)). At the last third stage, the resulting derivative undergoes hydrazinolysis at the substituted position with the formation of 1,10-disulfanyl-closo-decaborate anion. This compound in its reaction properties is very close to the substituted 2-sulfanyl-closo-decaborate anion at the equatorial position [2-B10H9(SH)]2-, which can easily undergo an alkylation reaction in the presence of a base. Bromoacetamide was used as an example, which made it possible to obtain a tetraacetylamide di-sulfonium derivative of the closo-decaborate anion (1,10-B10H8(S(CH2C(O)NH2)2)2(4)). The resulting compounds were characterized using multinuclear NMR spectroscopy on 11B, 1H, 13C nuclei, IR spectroscopy and elemental analysis. The structures of compounds 2, 3, 4 were determined by X-ray diffraction analysis. Based on X-ray diffraction data and Hirschfeld surface analysis, crystal packing and intermolecular interactions in compound 4 were studied.