Triethylenediamine (1,4-Diazabicyclo[2.2.2]octane, DABCO), is a caged tertiary diamine commonly used as a strong hindered amine base in chemical synthesis. It is used in the synthesis of isoxazole derivatives via dehydration of primary nitro compounds in the presence of dipolarophiles. It can also be employed as a complexing ligand and as a catalyst.