Reaction of Zirconocene−Carboryne Precursor with Alkynes: An Efficient Route to Zirconacyclopentenes Incorporating a Carboranyl Unit

Reaction of zirconocene−carboryne precursor Cp2Zr(μ-Cl)(μ-C2B10H10)Li(OEt2)2 with various kinds of alkynes R1CCR2 in refluxing toluene gives the monoinsertion products 1,2-[Cp2ZrC(R1)C(R2)]-1,2-C2B10H10 in good to very high isolated yields with very good chemo- and regioselectivity. This reaction offers an efficient route to zirconacyclopentenes incorporating a carboranyl unit, a carborane version of zirconacyclopentadienes. All complexes have been fully characterized by various spectroscopic techniques and single-crystal X-ray analyses.