Lowering the symmetry of difunctionalized coordination compounds via nucleophilic aromatic substitutions

RuII-coordinated 3,8-dibromo-1,10-phenanthroline undergoes nucleophilic aromatic substitutions with simple nucleophiles (e.g. thiolate) to give the disubstituted products in high yields. When a fluorenyl anion is used, a mono-substituted product is exclusively obtained. The highly acidic nature of this mono-substituted complex results in deprotonation under the reaction conditions and deactivation toward a second substitution reaction. A complex of lower symmetry that can be further functionalized using other transformations is obtained.