cis-to-trans Isomerization Promoted by Pyridine as a Crucial Step for the Selective Preparation of trans-Pt(SAr)(Cl)(PAr‘₃)₂

The general strategy for the syntheses of trans-Pt(SAr)(Cl)(PAr‘₃)₂ (1) (Ar = Ph, C₆H₄-2-Me, C₆H₄-3-OMe C₆H₄-2-F, etc.; Ar‘ = Ph, C₆H₄-4-OMe, C₆H₄-4-Me, and C₆H₄-4-CF₃) by the reaction of cis-PtCl₂(PAr‘₃)₂ with ArSH has been developed. The mechanistic investigation suggested that isomerization of cis-1 into trans-1 promoted by the combined use of C₆H₆ as a solvent and pyridine as a base was the key to the successful preparation of 1.