Organometallic chemistry and application of palladacycles in asymmetric hydrophosphination reactions.

A number of palladacycles containing chiral chelating auxiliaries have been utilized as efficient catalysts for asymmetric hydrophosphination reactions. In all cases, the chiral auxiliaries remained coordinated to the palladium centres throughout the course of the reactions. Despite the presence of a large quantity of powerful tertiary phosphines, which are known to be strong metal ion sequesters, the expected catalyst poisoning was rarely observed in these palladacycle catalyzed processes. This review highlights the unique stereoelectronic features and the important organometallic chemistry of palladacycle catalysts which are essential to their synthetic operations.

Chelating Phosphine-N-Heterocyclic Carbene Platinum Complexes via Catalytic Asymmetric Hydrophosphination and Their Cytotoxicity Toward MKN74 and MCF7 Cancer Cell Lines.

A series of activated vinyl azoles was hydrophosphinated in the presence of a chiral palladacycle catalyst under mild conditions to give enantioenriched phosphine azoles with moderate enantioselectivities and yields. The racemic phosphine azoles were transformed into eleven novel chelating phosphine-N-heterocyclic carbene (NHC) platinum complexes. The drug efficacies of nine selected phosphine-NHC platinum(II) chlorides in two cancer cell lines (MKN74 and MCF7) were evaluated, and two were found to exhibit activities comparable to that of cisplatin.