From phosphonium salts to binuclear ortho-palladated phosphorus ylides

This current piece of research presents an easy and direct way for the synthesis of binuclear ortho-palladated phosphorus ylide derivatives of acetone and chloroacetone in high yield and high purity by the reaction of the phosphonium salts [CH3COCH2PPh3]Cl (1) and [ClCH2COCH2R]Cl (R = PPh3 (2), R = P(PhMe)3 (3)) with palladium(II) acetate in methanol under mild conditions to afford the dimeric orthopalladated complexes, [Pd(CH3COCHPPh3)(μ-Cl)]2 (4), [Pd(ClCH2COCHPPh3)(μ-Cl)]2 (5) and [Pd(ClCH2COCHP(PhMe)3)(μ-Cl)]2 (6).

The reactions of Pd(OAc)2 with the phosphonium salts [CH3COCH2PPh3]Cl (1) and [ClCH2COCH2R]Cl (R = PPh3 (2), R = P(PhMe)3 (3)) lead to binuclear orthopalladated complexes of the type [Pd(CH3COCHPPh3)(μ-Cl)]2 (4), [Pd(ClCH2COCHPPh3)(μ-Cl)]2 (5) and [Pd(ClCH2COCHP(PhMe)3)(μ-Cl)]2 (6). X-ray analysis of 5 demonstrates a Cl bridged dimeric structure with C,C-chelated groups.Figure optionsDownload as PowerPoint slide