In general, the regioselective functionalization of the 2-position in 3- or 3,5-substituted bromobenzene derivatives afforded mixtures of 1,3,4- and 1,2,3- or 1,2,3,4- and 1,3,4,5-bromobenzene derivatives, respectively. We envisioned that 3-substituted 1,2-dibromobenzene derivatives could be regioselective functionalized in a halogen-metal exchange reaction. In order to test our hypothesis 1,2-dibromo-3-chlorobenzene (1a) was treated with butyllithium at -78 °C in ...