Notizen: Elektroreduktion organischer Verbindungen, XV [1] / Electroreduction of Organic Compounds, XV [1]

Abstract

Electroreduction, Chlorinated Benzenes and Biphenyls, D ehalogenationThe twelve possible chlorinated benzenes and the three isomeric m onochlorobiphenyls are electrochemically reduced in a divided cell in meth anol at a lead cathode. Chlorobenzene and ben zene or biphenyl, respectively, are formed with acceptable current yields and very good chemical yields. Die in Abb. 1 gezeigte Produktverteilung be zieht sich auf das 1,5-fache der theoretischen Gesamtladungsmenge. Die bei der R eduktion der Dichlorbenzolisomere beobachteten Verhältnisse der Produktverteilung bestätigen die in der Literatur Die bei industriellen

Dehalogenation of Aromatic Halides Using Metallic Calcium in Ethanol

“…Nevertheless, the interest in the recovery of reusable materials (e.g., PCBs are present mostly in transformer oils) and the necessity to treat contaminated products with low concentration of PCBs have renewed the interest in the dechlorination methods. The usual dechlorination methods of PCBs developed thus far (such as using sodium borohydride ( − ), photochemical dechlorination ( − ) or electroreduction ( − )) present several disadvantages that are the prevention of moisture, the generation of undesired byproducts, but also the high costs of the required materials and energy. Now, a few selective decontamination methods are available, based on chemical ( , ) or biological () dechlorination technolo gies.…”

The Mediated Reduction of Lindane in DMF

“…It should also be recognized that the thermodynamics of dechlorination of polychlorinated cyclohexanes are quite different from those for the dechlorination of polychlorinated benzenes. As is readily shown by voltammetry of a series of chlorinated derivatives, the reduction of polychlorinated benzenes, the removal of a chlorine atom always leads to a product that is more difficult to reduce [1,3,8,9]. In contrast, with lindane it must be concluded that the cleavage of carbon-chlorine bonds leads to species that are more readily reduced and the only stable product is the fully reduced aromatic, benzene.…”

Oxidation and Reduction of Halogen‐containing Compounds

“…An investigation of the electrochemistry of the entire family of chlorinated benzenes has been reported [65], and the dechlorinations of 1,2,3,5-tetrachlorobenzene [57] and of 2,4-dichlorophenoxyacetic acid (a herbicide) have been accomplished [66]. Several papers dealing with the reduction of chlorinated biphenyls have appeared [67][68][69].…”