Abstract
Investigation of tris(di-iso-propylphosphanylmethyl)phenylborate ([TP(iPr)](-)) organo-beryllium complexes [TP(iPr)]BeR with R = Ph, nBu, Cp, Cp* revealed transmetalation of [CH(2)P(iPr)(2)](-) groups from boron onto beryllium. This reaction is caused by partial dissociation of the scorpionate, which can be triggered through steric overcrowding of the beryllium atom or reducing the ligand beryllium bond strength through oxidation of the phosphorus atoms with selenium. Oxidation with oxygen or sulfur results in the formation of stable phosphine oxide and sulfide scorpionates.