Synthesis, characterization and catalytic evaluation in the Heck coupling reactions of S–P–S pincer complexes of the type [Pd{PhP(C6H4-2-S)2}(PAr3)]

A series of palladium complexes of the type [Pd(phPS2)(PAr3)] (phPS2) = [PhP(C6H4-2-S)2]2− have been synthesized in good yields and their crystal structures determined. Heck coupling reactions were carried out using the [Pd(phPS2)(PPh3)] (1), [Pd(phPS2){P(C6H4-4-Cl)3}] (2), [Pd(phPS2){P(C6H4-4-F)3}] (3), [Pd(phPS2){P(C6H4-4-CF3)3}] (4), [Pd(phPS2){P(C6H4-4-Me)3}] (5) and [Pd(phPS2){P(C6H4-4-OMe)3}] (6) complexes as catalyst precursors in order to examine the potential effect of the para-substituted triarylphosphines in the reaction of bromobenzene and styrene.