The Wurtz Fittig reaction is the name given to the chemical process for the preparation of alkylated aromatic compounds by sodium‐mediated coupling of an alkyl and an aryl halide. It was first discovered in 1860.
It has been used in the preparation of 'organosilicon' compounds (for example: silicone sealants).
More than 150 years after its discovery, details of how the reaction works remain unclear. There are presently two competing explanations - and there appears to be experimental evidence for both.
See: Wikipedia