Exhaustive chlorination of [B12H12]2- without chlorine gas and the use of [B12Cl12]2- as a Supporting anion in catalytic hydrodefluorination of aliphatic C-F bonds.

The fully chlorinated closo-dodecaborate salt Cs(2)[B(12)Cl(12)] was prepared in high yield from Cs(2)[B(12)H(12)] and SO(2)Cl(2) in acetonitrile at refluxing temperature. [Ph(3)C](2)[B(12)Cl(12)] was obtained by simple metathesis reactions. Catalytic hydrodefluorination of benzotrifluoride sp(3) C-F bonds was accomplished using [Ph(3)C](2)[B(12)Cl(12)] as a precatalyst and Et(3)SiH as a stoichiometric reagent. Full consumption of the sp(3) C-F bonds in p-FC(6)H(4)CF(3) and C(6)F(5)CF(3) with a turnover number up to 2000 was achieved.