Catalytic Condensation of Primary Amines, Dehydrogenation of Secondary Amines, and Dealkylation of Tertiary Amines over Solid-State Rhenium Sulfide Clusters with an Octahedral Metal Framework

When solid-state rhenium sulfide clusters with an octahedral metal framework are treated in a hydrogen stream above 300 °C, a catalytic activity for condensation of butylamine to yield N-butylidenebutylamine develops. Primary amines such as ethylamine, pentylamine, and hexylamine are also converted to the corresponding N-alkylidenealkylamines. Secondary amines such as diethylamine, dipropylamine, and dibutylamine are dehydrogenated to the corresponding N-alkylidenealkylamines. When triethylamine is allowed to react, dealkylation proceeds to yield diethylamine and its dehydrogenated product N-ethylideneethylamine. Trimethylamine is also dealkylated to dimethylamine. This series of catalytic behavior is the same as that of palladium and platinum metals. The similarity in selectivity is attributable to the rhenium atom that accepts electrons from the sulfur ligands leading to isoelectronic with the platinum group metals.