Metallaaromatics Containing Main‐group Heteroatoms

Metallaaromatics are metallacycles that are derived from the formal replacement of a carbon atom in the framework of organic aromatics with a metal fragment. As an important subclass of metallaaromatics, metallaaromatics that contain main‐group heteroatoms have attracted considerable attention. In the past ten years, we have developed several new methods to construct metallaaromatics as well as those containing main‐group heteroatoms, such as metallapyridine, metallapyridinium, metallapyridyne, metallafuran, metallabenzothiazole, metallabenzoxazole, metallabenzthiophene, aza‐metallapentalene and some novel tricyclic/tetracyclic metallaaromatics. In addition, interesting reactions such as the first hetero‐Diels Alder reaction between 1‐metalla‐1,3‐dienes and nitriles, the first intramolecular nucleophilic aromatic substitution (S N Ar) reaction of metallabenzene, and the first iodine‐mediated electrophilic cyclizations of a metallabenzene complex were demonstrated. In this account, recent and novel approaches for their synthesis and property analyses are summarized. The structural diversity and unique properties of metallaaromatics containing main‐group heteroatoms will strongly inspire further investigation of these species and provide a wide range of potential applications.