Transition metal–carbon multiple bonds

Since the discovery of the first example of a transition metal carbene complex 37 years ago, and a transition metal carbyne complex a few years later, investigations into the chemistry of compounds that contain multiple metal–carbon bonds have continued steadily. Many compounds that contain multiple metal–carbon bonds are now established as catalysts or stoichiometric reagents in organic chemistry. In this perspective, important steps in the development of transition metal–carbon multiple bond chemistry, in particular chemistry in which the metal is in it's highest possible oxidation state, are highlighted, and possible avenues for further advances are suggested.