Ruthenium complexes of the type [RuH (η5-CB)(PPh3) 2]{CB is a monoanionic charge- compensated carborane ligand such as [9-SR2-7, 8-C2B9H10]− and [9-SR2-7-CH3-7, 8- C2B9H9]−} efficiently catalyse the Kharasch addition of CCl4 across olefins and, with maximum total turnover numbers of 9000 and initial turnover frequencies of 1900 h− 1 at 40° C, highly surpass their Ru–Cp# analogues in these reactions.
