Synthesis and characterization of sterically hindered thiolate Pd(II) complexes of the type [Pd(SR)2(TMEDA)]: Examination of their catalytic properties in phosphane-free Suzuki-Miyaura cross couplings

The sterically hindered thiolate complexes [Pd(SR)2(TMEDA)] SR = SC6F5 (2), SC6F4-4-H (3), SC6H4-2-SiPh3 (4) were easily synthesized by metathetical reactions of the corresponding palladium chloro compound [Pd(Cl)2(TMEDA)] (1) and the lead salt of the corresponding thiol. The identity of the three species being unequivocally determined by single crystal X-ray diffraction techniques. The catalytic activity of the palladium species [Pd(SR)2(TMEDA)] was explored in the Suzuki–Miyaura cross coupling reactions of different p-substituted bromobenzenes.