2,3-Dimethylbutadiene can be highly selectively hydrogenated to 2,3-dimethyl-1-butene with a new catalyst based on silica supported copper nanoparticles (Cu-NPs) prepared via surface organometallic chemistry. Mesityl-copper was firmly grafted onto silica and the reduction of the resulting surface species under hydrogen at 350 °C led to well-dispersed Cu-NPs. Prior to catalytic tests, the final catalysts as well as the intermediates were characterised by DRIFT, SS NMR, EPR, TEM, XRD and elemental analyses.