Reduction of aromatic nitro compounds with 2-mercaptoethanol and oxidation of thiophenol with molecular oxygen mediated by trinuclear iron acetate complexes

Abstract

Aromatic nitro compounds (1a–h) were selectively reduced by 2-mercaptoethanol (3a) in the presence of trinuclear acetate complexes [Fe^III₂M^IIO(OAc)₆(py)₃][(5a; M = Fe), (5b; M = Mn), (5c; M = Co), and (5d; M = Ni)] to give the corresponding amines (2a–h). The reaction was found to follow pseudo-first-order kinetics. The activity order of these complexes for the reduction followed the sequence (5b) > (5a) > (5d) > (5c). These complexes also efficiently catalysed oxidation of thiophenol (3b) with molecular oxygen toproduce diphenyl disulphide (4b) quantitatively. The activity order of the complexes for the oxidation was similar to that observed in the reduction of nitro compounds.