Gatterman reaction : Formation of chloro benzene, Bromobenzene from benzene diazonium salts with reagents `Cu//Hcl, Cu//HBr` is referred as gatterman reaction.
`C_(6)H_(5)N_(2).^(+)X^(-) overset(Cu//HCl) to C_(6)H_(5)Cl+N_(2)+CuX`
`C_(6)H_(5)N_(2).^(+)X^(-) overset(Cu//HBr) to C_(6)H_(5)Br+N_(2)+CuX`
