Carbon–carbon and carbon–chlorine bond formation on reaction of iodine(III) reagents with the bis(alkynyl)palladium(II) motif, and structural chemistry of trans-Pd(C [tbnd]C- o-Tol) 2(PMe 2Ph) 2] and trans-[PdCl(C [tbnd]C- o-Tol)(PMe 2Ph) 2

Abstract

Trans-di( ortho-tolylethynyl)bis(dimethylphenylphosphine)palladium(II) reacts above −20 °C with the iodonium reagent IPhCl 2 to give predominantly o-Tol–C C–Cl, above 15 °C with IPh 2(OTf) (OTf = triflate) to give o-Tol–C C–Ph and ( o-Tol–C C) 2 in ca. 3:1 ratio, and above 10 °C with IPh(C CR)(OTf) (R = Bu t, SiMe 3) to give predominantly o-Tol–C C–C C–R and ( o-Tol–C C) 2. 31P NMR spectra provide evidence for detection of intermediates. The complexes trans-[Pd(C C- o-Tol) 2(PMe 2Ph) 2] and trans-[PdCl(C C- o-Tol)(PMe 2Ph) 2] are obtained on reaction of trans-[PdCl 2(PMe 2Ph) 2] with Li(C C- o-Tol) and o-Tol-C CH/Et 3N, respectively, and have been characterised by X-ray crystallography.