1: sodium tetrahydroborate; NiII chloride hexahydrate / methanol / 1 h 2: formic acid / 4 h / Reflux 3: oxygen; tetra-n-butylammonium acetate; palladium diacetate; potassium carbonate; copper(ll) bromide; iron(II) chloride / N,N-dimethyl-formamide / 24 h / 130 °C / 760.05 Torr View Scheme

1: sodium tetrahydroborate; NiII chloride hexahydrate / methanol / 1 h 2: oxygen; tetra-n-butylammonium acetate; palladium diacetate; potassium carbonate; copper(ll) bromide; iron(II) chloride / N,N-dimethyl-formamide / 24 h / 130 °C / 760.05 Torr View Scheme