Ansa-methylene-substituted cobalt bis(dicarbollide) ion available via an easy click: a carbene-like mechanism.

Herein we report on the carbon-bridged derivative of the [(1,2-C2B9H11)2-3,3'-Co]- ion, accessible through a low-temperature reaction with BuLi and CH2Cl2. We propose that addition of a carbene intermediate to the cage is responsible for product formation. This mechanism is supported by computational chemistry and single-crystal X-ray diffraction. Moreover, the isolation of dicluster dianions interconnected via bridging carbons reveals another unique feature of this system.