A Borenium Cation Stabilized by an N-Heterocyclic Carbene Ligand

Abstract

Reaction of Mes 2 BF with trimethylsilyl triflate (Me 3 SiOTf) and [Ag(IMe) 2 ][Ag 2 I 3 ] (IMe = 1,3-dimethylimidazol-2-ylidene) in refluxing chlorobenzene affords the carbene-stabilized borenium salt [(IMe)BMes 2 ]OTf ([ 1 ][OTf]). As indicated by cyclic voltammetry, [ 1 ] + is reversibly reduced to produce a radical that has been characterized by EPR spectroscopy.