The reaction of [Ph 3 PCH 2 -(E)-C(Me)dC(H)PPh 3 ]Cl 2 (1b) with PtCl 2 (NCPh) 2 (1:1 molar ratio) in refluxing 2-methoxyethanol gives the ortho-metalated complex [Pt(C 6 H 3 -3-Ph-2-PPh 2 -CdC(Me)CH 2 PPh 2 -κC,C,P)Cl] (3). The synthesis of complex 3 formally involves three C-H and one C-P bond activation and one C-C bond coupling. Complex 3 reacts with excess KBr or NaI to give, after halide metathesis, the complexes [Pt(C 6 H 3 -3-Ph-2-PPh 2 -CdC(Me)CH 2 PPh 2 -κC,C,P)X] (X ) Br (4), I ( 5)). Complex 5 has been characterized by X-ray diffraction methods. The influences of several factors, such as the solvent, the platinum starting complex, and the bis-phosphonium salt, in the synthesis of 3 have been examined, and a plausible reaction mechanism for the synthesis of 3 is proposed. This mechanism is supported by the isolation of the Pt(IV) derivative [Pt(C 6 H 4 -4-F){C 6 H 3 -5-F-2-P(p-FC 6 H 4 ) 2 -CdC(Me)CH 2 P(p-FC 6 H 4 ) 2 -κC,C,P}Cl 2 ] (6), obtained by reaction of [(p-FC 6 H 4 ) 3 PCH 2 -(E)-C(Me)dC(H)P(p-FC 6 H 4 ) 3 ]Cl 2 (1f) with PtCl 2 (NCPh) 2 in refluxing 2-methoxyethanol. Complex 3 reacts with AgClO 4 and neutral monodentate (L) and bidentate (L-L) ligands, giving the cationic derivatives 12)). Complex 3 reacts with excess X 2 (Cl 2 , I 2 ) to give the expected Pt(IV) derivatives [Pt(C 6 H 3 -3-Ph-2-PPh 2 -CdC(Me)CH 2 PPh 2 -κC,C,P)-(Cl)(X) 2 ] ((X) 2 ) (Cl) 2 (13), (I) 2 ( 14)) through a typical oxidative addition process. Complex 14 has also been characterized by X-ray diffraction methods.