Reaction conditions: 1a (0.1 mmol, 1 equiv.), catalyst (0.01 mmol, 0.1 equiv.), ligand (0.01 mmol, 0.1 equiv.), and additive (0.02 mmol, 0.2 equiv.) in solvent (1.0 ml) at T (°C) for 48 hours. MS, molecular sieves; phen, 1,10-phenanthroline; bpy, bipyridine; THF, tetrahydrofuran; n.r., no reaction.