Enzymatic electrochemical continuous flow cascade synthesis of substituted benzimidazoles

A green and efficient method for the synthesis of substituted benzimidazoles has been developed in a two-step continuous flow system. Enzymatic electrochemical cascade reactions between aromatic alcohols and o-phenylenediamines are reported. The reaction was performed under mild reaction conditions with air as the "green"oxidant and oxidase as the biocatalyst. Alcohol oxidation and substituted benzimidazole formation, which are usually accomplished separately, were integrated into a single operation. A scale up experiment was completed successfully in a continuous flow system which offers an industrially relevant, practical and efficient method.