C-H activation of arenes and heteroarenes by early transition metallaborane, [(Cp*Ta)<inf>2</inf>B<inf>5</inf>H<inf>11</inf>] (Cp* = η⁵-C<inf>5</inf>Me<inf>5</inf>)

C-H activation of arenes and heteroarenes has been achieved by a hydrogen rich tantalaborane cluster [(Cp*Ta)2B5H 11] that leads to the formation of C-H functionalized products. Furthermore, we examined the reaction of substituted thiophene and pyrrole derivatives with tantalaborane which provided a convenient and efficient route to regio-defined C-H functionalized heteroarenes. © 2011 The Royal Society of Chemistry.