Greener dechlorination

A greener way to dechlorinate the pesticide DDT (dichlorodiphenyltrichloroethane) is being developed by Japanese researchers.

Recent environmental concerns have generated a need for efficient methods to dehalogenate chlorinated organic compounds, which accumulate in soils. Inspired by the fact that vitamin B ₁₂-dependent enzymes catalyse various molecular transformations, Yoshio Hisaeda and co-workers from Kyushu University are investigating a hydrophobic vitamin B ₁₂. By combining a catalytic amount of the hydrophobic vitamin B ₁₂ with a ruthenium-based photosensitiser the team can dechlorinate DDT under visible light.

This new method, Hisaeda says, is superior to chemically redundant systems from the viewpoint of green chemistry and is simpler than an electrochemical system.

In future work Hisaeda hopes to be able to use this catalytic system in various organic syntheses as an environmentally friendly method. Such reactions, he speculates, could include asymmetric reductions, migrations and ring expansions.

Helen Fletcher