Benzophenone reduction using sulphur-based additives

Abstract Pyrite and γ-Fe 2 S 3 are the best of the mineral promotors tried for the CO—H 2 O reduction of benzophenone to diphenylmethane. A mixture of ferrous sulphide and sulphur matches the promotional effect of iron pyrite, which implies that sulphur plays a role in the reaction. Both elemental sulphur and hydrogen sulphide are shown to promote CO—H 2 O-induced reductions.