Tuning Surfactant Chain Length in a Metallomicellar Catalyst System to Study Organic Transformations in Water Medium

The hydrophobicity of alkyl chain plays crucial role in the aggregation behavior of metallomicelle-forming coordination complexes, in water, thereby influences the reaction rates of metallomicelle catalyzed organic reactions. Here, we have demonstrated the chain length variation for alkyl group that is covalently attached to ligand backbone of a MoO₂(L_n)(OH₂) type complex showing metallomicelle formation in water when the alkyl group is eight-carbon chain or beyond. The impact of alkyl chain length on reactivity of organic transformation was systematically studied for oxidative coupling of benzylic alcohol with 1,2-diaminobenzene forming benzimidazole, in water, as a model reaction. The efficiency of Mo-complexes increases with chain length for the mentioned organic reaction performed in water medium under open air as sole oxidant without the involvement of base/additive, thus making the protocol attractive. This work develops a unique study to understand organic reactions in micellar medium as well as an efficient pathway for the direct synthesis of benzimidazoles from alcohols and diamines.