ELECTROPHILIC MERCURATION OF ICOSAHEDRAL MONOCOBALTACARBORANES

Electrophilic mercuration of cobaltacarboranes 1,2-R(2)-3-Cp-3,1,2-CoC 2B9H9 (1) where R = H (1a), CH2OH (Ib) was studied. Dimercurated compl exes containing Hg atoms bound with boron atoms in positions 9 and 12 of the dicarbollyl ligand are the main products of the reaction with s trong electrophiles such as mercury acetate or trifluoroacetate in the corresponding acids. Mercuration of 1a under milder conditions, i.e., with Hg(OCOCF3)(2) in CH2Cl2 or Hg(OAc)(2) in a CH2Cl2-AcOH mixture, affords 9-monomercurated complexes as the main products.