Chelating phosphorus ligand which forms a 1:1 complex with NiCl2, which is an efficient catalyst for the coupling of Grignard reagents with aryl, vinylic or heterocyclic halides: Bull. Chem. Soc. Jpn., 49, 1958 (1976); Tetrahedron, 38, 3347 (1982); Synthesis, 386 (1988). Successful Suzuki coupling of arylboronic acids with aryl chlorides bearing electron-withdrawing groups was achieved in the presence of Palladium(II)- acetate,and dppp: Tetrahedron Lett., 38, 5575 (1997).