Ligand-Cyclometallation on Rh(I) Complexes Initiated by Cyclic Organotin Compounds Leads Oxidatively to Rh(III) Analogues

Abstract

Reactions of [RhCIL₃], where L = PEt₃, PBU₃ⁿ, PPh₃, with (R₂Sn)_n
(in slight excess), where R = Me or Ph, n = 6 and R = Et. n = 9, were
carried out in the hope of obtaining rhodium(l) complexes formed by
insertion of R₂Sn moieties into Rh—Cl bonds. The ³¹P NMR spectral
data of the reaction mixtures showed that no Rh—Sn species could be
detected in the products, but rather an interesting new complex, formed
by cyclometallation involving a  β-hydrogen transfer from the ligands
PEt₃ or PBu₃ⁿ, or from the ortho-carbanato of the phenyl group of
PPh₃ in the complexes [RhClL₃], to form the Rh(III) complexes. Explanations
of such results are given and discussed.