Abstract
Organometallic intramolecular-coordination five-membered ring compounds show high reactivity and high selectivity. Therefore, these many compounds have been synthesized since around mid 1960s. More than 50 kinds of metals are found as the metal elements, and these compounds are very widely used as intermediates and catalysts for organic syntheses.
I am grateful to Dr. Sumio Chubachi for reading the full manuscript, which enhanced its accuracy and clarity, and for providing valuable constructive criticism.