Imidazolines are a class of heterocycles derived from imidazoles by reduction of one of the two double bonds. Three isomers are known, 2-imidazoline, 3-imidazoline and 4-imidazoline. 2 and 3-imidazolines contain imine centers, while 4-imidazolines contain alkene groups. The 2-imidazoline group occurs in several drugs. Imidazolines are an important class of compounds found in many natural and medicinal products. These compounds are also used as intermediates in the synthesis of organic molecules. Furthermore, chiral imidazolines are widely used as organic catalysts for the synthesis of various natural and synthetic organic compounds.
Oxazolines are five-membered heterocyclic compounds with one double bond. The double bond may be in one of three positions, so there may be three different oxazoline rings. The 2-oxazoline structure is the most common, and 3-oxazoline and 4-oxazoline exist mainly as laboratory research compounds. Oxazolines exist between oxazole and oxazolidine in terms of saturation.