Synthesis, characterization and crystal structures of two new platinum complexes with planar chiral 1,2-disubstituted ferrocenes containing phosphine and thioether donor groups

The platinum complex [1,2-Fc(PPh2)(CH2SPh)]PtCl21 has been transformed into [1,2-Fc(PPh2)(CH2SPh)]PtCl(SnCl3) 2 as a single isomer, in high yields, by reaction with SnCl2. The SnCl2 reagent inserts regioselectively in the PtCl bond trans to the sulphur atom, while the sulphur atom configuration is fully controlled by the planar chirality of the P,S ligand. Complex 1 has also been efficiently reduced in the presence of diphenylacetylene to a single isomer of [1,2-Fc(PPh2)(CH2SPh)]Pt(PhCCPh), 5, where the central chirality on sulphur is again maintained. In compound 5, the central CC bond of the diphenylacetylene moiety acquires a strong double bond character. The structures of complexes 1 and 5 have been determined by X-ray diffraction on monocrystals. To the best of our knowledge, this study presents the first example of fully characterized L2PtCl(SnCl3) and L2Pt(PhCCPh) complexes, L2 being a P,S ligand.