Hindered bidentate ligand used in, for example, the Ni-catalyzed Suzuki-type crossed coupling of arylboronic acids with aryl mesylates to give biaryls: J. Org. Chem., 60, 1060, 1066 (1995), and of thiophenolates with aryl mesylates to give unsymmetrical diaryl sulfides: J. Org. Chem., 60, 6895 (1995).