Dehalogenation, polyhalogenated

The reductive dehalogenation of polyhalogenated methanes (Castro et al. 1985) and polyhalogenated ethanes (Li and Wackett 1993) by Pseudomonas putida strain PpG786. 

Anaerobic dehalogenation has also been observed in aromatic ethers including polychlorinated dibenzo[l,4]dioxins (Fennell et al. 2004 Yoshida et al. 2005). The anaerobic debromination of decabromodiphenyl ether is considered here since it is analogous to the dehalogenation of polyhalogenated biphenyls. 

The data highlight the compatibility of the catalytic system for dehalogenation of both electron-rich (Table 8.1, entry 5) and electron-poor (Table 8.1, entry 8) snbstrates, sterically hindered orf/to-substitnted componnds, heteroaromatics (Table 8.1, entry 9), polyhalogenated species (Table 8.1, entry 10), and those bearing... 

The dehalogenation of several types of polyhalogenated arenes has been studied by Hofs group [61-67]. Brominated thiophenes and bithiophenes were re-... 

Nastainczyk W, Ahr H, Ulrich V, et al. 1982a. The mechanism of the reductive dehalogenation of polyhalogenated compounds by microsomal cytochrome P450. 799-808. 

Some investigations directed to the dehalogenation of polyhalogenated organic derivatives by means of tellurium reagents have been reported. 

The influence of electron density distiibution in the radical-anioa on the rate of carbon-halogen bond cleavage was discussed on page 94. This effect makes possible the selective dehalogenation of polyhalogen aromatic compounds. Examples... 

In the following we will try to illustrate these general points by discussing two specific types of redox reactions the reduction of aromatic nitro groups (Eq. 14-9) and the reductive dehalogenation of polyhalogenated Cr and C2-compounds (Eqs. 14-6 to 14-8). These two cases represent two very different types of reactions. In the first case, the transfer of the first electron is reversible, whereas in the second case, it is typically irreversible and involves the breaking of a bond. In the latter case, therefore, one speaks of a dissociative electron transfer. Furthermore, compounds... 

Silver electrodes have been employed in form of an expanded silver sheet on a plastic plate in the dehalogenation of polyhalogenated heterocyclic compounds examples are given in Chapter 18. 

Certain metal carbonyls are very useful for the removal of halogens from polyhalogenated compounds. In these reactions, again, an oxidative addition step should be important. As shown below, carbenes 33>, cyclobutadiene 34>, and benzyne complexes 35> are formed by the dehalogenation reaction with metal carbonyls. 

Birke V, Mattik J, Runne D. Mechanochemical reductive dehalogenation of hazardous polyhalogenated contaminants. J Mat Sci 2004 39 5111-6. 

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