Benzene or an alkylbenzene is reacted with hydrogen and an alkali metal such as potassium in the presence of a polyamine to produce cyclohexene or alkylcyclohexene and alkali metal hydride. The polyamine contains only C, N and H and has at least three nitrogens. Each nitrogen is linked to three carbons and each carbon bridge is at least two methylenes long. Representative polyamines are hexamethyl hexacyclen, hexamethyl triethylene tetraamine, tris(2-dimethylamino ethyl)amine and octamethyl pentaethylene hexamine. Cyclohexene is produced at high ratios with respect to cyclohexane.