C-C coupling of aryl groups and allyl derivatives on Pt(II)-phenanthroline fragments: crystal and molecular structure of the tpb[(n1,n2-2-allyl-5-methyl-phenyl)iodo(1,10-phenanthroline)platinum(II)] complex containing the N-N ligand in axial-equatorial coordination mode

The reactions between allyl compounds CH2CHCH2Fn bearing electron-withdrawing functional (Fn) groups and cationic {Pt(aryl)(1,10-phenanthroline)}+ fragments generated in situ are described. The aryl and platinum addition to the terminal and, respectively, internal unsaturated carbon is generally observed. The subsequent H–Caryl bond activation, followed by HFn elimination, affords the ortho organic fragment (Pt)–aryl-CH2CHCH2 η1,η2-chelate to the platinum. This process does not occur when the regiochemistry is of Markownikov type and the Pt–CH2CH(aryl)CH2Fn fragment is formed. The described results are compared with those concerning the behaviour of unsubstituted α-olefins. The X-ray crystal structure of the title five-coordinate complex shows a distorted tbp arrangement of the ligands with the iodide in the equatorial plane and the unusual axial-equatorial coordination mode of the 1,10-phenanthroline.