Synthesis and Chemical Properties of Metallabenzynes

Abstract

Metallabenzynes are an interesting class of metallaraomatics. They can be regarded as transition-metal analogs of benzyne in which a C atom is replaced by an isolobal transition metal fragment. The chemistry of this class of compounds has received much recent attention. A series of metallabenzynes containing osmium and rhenium have been isolated. It has also been demonstrated both experimentally and theoretically that metallabenzynes can have properties of both aromatic organic compounds and organometallic compounds. For example, metallabenzynes, like organic aromatic compounds, could undergo electrophilic substitution reactions to give new metallabenzynes; react with nucleophiles to generate metallabenzene species through addition of nucleophiles at the carbyne carbons of metallabenzynes and undergo reductive elimination to give carbene complexes.

Recent Advances in the Reactions of Cyclic Carbynes

“…The incorporation of a metal center into the acetylenic carbon would stabilize the strained cyclic carbon cycles containing alkynes. The cyclic carbynes obtained until now could be classified as six-membered metallabenzynes [14][15][16][17][18][19][20][21] A and five-membered metallapentalynes [22][23][24] B (Figure 2). In addition, the first metallapyridyne [25] was documented by Xia and coworkers, providing one precious example of cyclic carbynes.…”

“…The thorough investigation of the reactivities and properties might provide a new perspective for the application of late-transition-metal carbyne species as prosperous catalysts in various organic reactions. The chemistry of metallabenzynes has been fully illustrated and nicely reviewed [14][15][16][17][18][19][20][21]. However, there is no review paper covering the entirety of cyclic carbynes (metallabenzynes and metallapentalynes).…”