Synthesis of Cumulenylidene Complexes

The majority of butatrienylidene complexes synthesized or generated so far were obtained by following route a and using butadiyne or a butadiyne derivative as the source of the C4 fragment. A few complexes of iridium or manganese were synthesized by the substitution route c. Until now route b has not been (successfijlly) employed. 

The first butatrienylidene complexes were generated by Bruce et al. [14] and Lomprey and Selegue [15, 16[ in 1993. 

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