Abstract:The synthesis of two bis(carboranyl) (bc) magnesium reagents is described. Treatment of 1,1′-bis(o-carborane) (H 2 -bc) or 8,8′,9,9′,10,10′,12,12′-octamethyl-1,1′-bis(o-carborane) (H 2 -Mebc) with Mg(nBu) 2 in 1,2-dimethoxyethane (DME) affords (bc)Mg(DME) 2 (1a,b) as crystalline solids. The magnesium compounds, which have been characterized by NMR spectroscopy and single-crystal X-ray crystallography in the case of 1a, serve as competent Grignard-type reagents to generate bc-con-