We must take into account that many heteromonocycle compounds have been known for more than 100 years, and that they were isolated from natural products. In the absence of a systematic nomenclature, they were originally given common names related to their origin, with some property, ect. These names are so ingrained that, even if there are systematic alternatives, the IUPAC does not aspire to their use, but rather recommends the former.

The most important common named heterocycles are listed below.

[1] Pyrrole

[2] Furan

[3] Thiophene

[4] Imidazole

[5] Pyridine

[6] Pyrimidine

[7] Piperidine

[8] Pyrrolidine

[9] Morpholine

[10] Quinoline

[11] Isoquinoline