Multidonor Ligands. 3. Cyclopalladation of py{SCH2C(O)R}-2 (py-2 = 2-pyridyl, R = Ph, Me, OMe) through a C(sp3)−H Bond Activation

[PdCl 2 (NCPh) 2 ] reacts with R−carbonylmethylenethiopyridines [py{SCH 2 C(O)R}-2] to give, depending on the substituent R and the reaction conditions, or the coordination complexes [Pd{py{SCH 2 C(O)R}-2} 2 Cl 2 ] (R = Ph, Me, OMe). The latter can be doubly deprotonated by a base (Na 2 CO 3 or NaH) to give dicyclometalated complexes These transmetalate one ligand to [PdCl 2 (NCPh) 2 ] to give which in turn reacts with (Me 4 N)Cl or with monodentate ligands L or with MeCN in the presence of AgClO 4 to give anionic neutral [R = Ph, L = PPh 3, py{SCH 2 C(O)Ph}-2, t BuNC, NH 2 CH(Me)Ph, pyridine (py), tetrahydrothiophene (tht); R = Me, L = PPh 3, py, tht], or cationic (R = Ph, Me, OMe) complexes, respectively. The latter react with PPh 3 or with bidentate ligands to give complexes or [L = PPh 3, L 2 = N, N, N ‘, N ‘-tetramethylethylenediamine (tmeda) or 2,2‘-bipyridine (bipy)]. The crystal structures of and have been determined.