Cobalt-promoted B-H and C-H activation in the three-component reactions of 16-electron cobalt carboranedithiolate, alkyne and bronsted acids

The reaction of the 16e species (MeCp)CoS2C2B10H10, methyl propiolate and cyclopentadiene at ambient temperature has led to the B-C coupled complex between Cp ligand and carborane cage. An unusual in situ-generated 3e donor o-carborane dithio ligand appears which bears a moiety formed by a [4 + 2] Diels-Alder cycloaddition. MeCp remains intact on the metal and the applied free CpH is oxidized to metal for further Diels-Alder addition with the olefinic unit.243