Metallaaromatics, a new class of aromatic heterocycles, are organometallic compounds derived from formal replacement of a carbon atom in organic aromatics with an isolobal transition-metal fragment. They have attracted considerable attention because of their aromatic properties and organometallic reactivities. Since the first examples of stable metallaaromatics, that is, metallabenzenes, reported in 1982, the synthesis of various metallaaromatics has been widely investigated. However, the isolation of metallaphenols, which can be viewed as closely related derivatives of metallabenzenes, has met with limited success.
Hong Zhang, Haiping Xia, and co-workers, Xiamen University, China, have demonstrated progress in the synthetic methodology of metallaaromatics by the construction of the first example of a m-metallaphenol, [Os{CHC(PPh3)CHC(OH)CH}(Ph3P)2(SCN)2], by a formal [5+1] cyclization. This new addition of the metallaaromatic family has been well characterized and shown to have aromatic character according to the criteria of geometry, magnetic properties, reactivity, and aromatic stabilization energy. This compound was also shown to undergo typical reactions of aromatic systems, e.g., nucleophilic substitution reactions, and phenols, e.g., formation of urethane linkages with isocyanates.
- Synthesis and Reactivity Studies of m-Metallaphenol,
Feifei Han, Tongdao Wang, Jinhua Li, Hong Zhang, Haiping Xia,
Chem. Eur. J. 2014.
DOI: 10.1002/chem.201304957
