Conversion of <i>trans</i>-Bromoboryl Platinum Complexes into their <i>cis</i>-Analogues upon Treatment with Chelating Bisphosphines

Oxidative addition of B−halogen bonds to Pt(0) centers generally leads to corresponding trans-halo(boryl)complexes. Here, we report on a series of unprecedented cis-bromo(boryl)species of the type cis-[(dcpe)Pt{B(Br)R)(Br)], which were obtained from corresponding complexes trans-[(Cy3P)2Pt{B(Br)R}(Br)] (R = Fc, Pip, Mes) (Cy = cyclohexyl; Fc = ferroceny; Pip = piperidyl, Mes = mesityl) upon treatment with the chelating bisphosphine dcpe (=bis(dicyclohexyl)phosphinoethane). In CH2Cl2 solution and in the presence of PCy3, one of these products, cis-[(dcpe)Pt{B(Br)Mes)(Br)], is converted into the corresponding chloroboryl complex cis-[(dcpe)Pt{B(Cl)Mes)(Br)]. All compounds were fully characterized by multinuclear NMR spectroscopy and single-crystal X-ray analyses.