Confusion, inversion, and creation--a new spring from porphyrin chemistry

This article mainly deals with the recent serendipity of novel porphyrin analogs such as N-confused porphyrin. The unique property of this ligand allows the formation of a variety of metal complexes. The important aspect of dynamic flipping (inversion), induced either by confusion or expansion of the macrocyclic core, that leads to the generation of new porphyrinoids, is emphasized. This review concludes with the recent progress on expanded porphyrins bearing confused, inverted, and fused pyrrole rings.