Electrochemical hydrodehalogenation

Cheng, H., Scott, K. and Christensen, P.A. (2003a) Electrochemical hydrodehalogenation of chlorinated phenols in aqueous solutions. J. Electrochem. Soc. 150, D17-D24. 

Chetty, R., Christensen, P.A., Golding, B.T. and Scott, K. (2004) Fundamental and applied studies on the electrochemical hydrodehalogenation of halogenated phenols at a palladised titanium electrode. Appl. Catal. A General 271, 185-194. 

Principles and Applications of Solid Polymer Electrolyte Reactors for Electrochemical Hydrodehalogenation of Organic Pollutants... 

Cheng H, Scott K, Christensen PA (2004) Electrochemical hydrodehalogenation of 2,4-dichlorophenol in paraffin oil and comparison with aqueous systems. J Electroanal Chem 566 131-138... 

Durante C, Isse AA, Sandona G, Germaro A (2009) Electrochemical hydrodehalogenation of polychloro-methanes at silver and carbon electrodes. Appl Cat B 88 479 89... 

In outer-sphere SET reductions (e.g., in electrochemical dehalogenations), hydrogen abstraction by R leads to the product RH (i.e., no step related to (ii) is required to occur). Process (ii) follows generally the activation of the substrate in the proposed hydrodehalogenation cycles, but we know also of opposite examples [77, 82, 106, 112],... 

Electrochemical methods for the reduction of halides have also been used in synthesis. For example, in the presence of chromium(II) salts as catalysts, deoxynucleosides have been prepared in DMF solutions with the use of a platinum electrode32. a-Halocarbonyl compounds have also been hydrodehalogenated in this way63,64. It should be noted, however, that this method is not always successful and significant problems have been reported in some instances65. 

Polyhaloacetic acids and their partially hydrodehalogenated products represent a second important family of herbicide-/pesticide-derived substrates. In their review on the environmental applications of industrial electrochemistry, Juttner and co-authors (Juttner et al. 2000) documented the electroreductive dechlorination of dichloroacetic acid (a by-product of monochloroacetic acid), a way to recover the valuable compound and avoid wastes. The electrochemical reduction of polychloro- and polybromo-derivatives was performed by Korshin and Jensen (2001) on Cu and Au cathodes. Complete dehalogenation was obtained for all substrates, but for monochloroacetic acid. To overcome the intrinsic poor reactivity of the monochloro-derivative the photoelectrochemical properties of a p-doped SiC electrode were investigated (Schnabel et al. 2001) however, the dehalogenation stopped at monochloroacetic acid. 

Minguzzi A, Lugaresi O, Aricci G, Rondinini S, Vertova A (2012) Silver nanoparticles for hydrodehalogenation reduction evidence of a synergistic effect between eatalyst and support. Electrochem Commun 22 25—28. doi 10.1016/j. elecom.2012.05.014... 

---