Metal-Mediated Reductive Hydrodehalogenation of Organic Halides

Liquid-phase hydrodechlorination of chlorinated benzenes over active carbon supported nickel catalysts under mild conditions

“…Polychlorinated biphenyls (PCBs), polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are carcinogenic, mutagenic, and not biodegradable. Among the destruction methods [1] proposed for chlorinated organic compounds, catalytic hydrodechlorination (HDC) is receiving more and more attention because it prevents the formation of more toxic compounds, such as PCDDs and PCDFs (generally known as dioxins). Noble metal catalysts, like Pd, Rh, Pt on different supports [2][3][4][5][6][7][8][9] are active for the reaction under mild conditions, but few of these catalysts are adopted to large-scale applications because of their high cost [10,11].…”

Exceptionally efficient catalytic hydrodechlorination of persistent organic pollutants: application of new sterically shielded palladium carbene complexes

“…In particular, palladium carbene complexes are well known to be suitable catalysts for the foregoing reactions. As an example, Nolan et al demonstrated that an in situ generated palladium carbene catalyst based on Pd(dba) 2 , potassium methoxide, and various imidazolium salts resulted in high yields of hydrodehalogenation products upon reaction in dioxane solution at 100°C (TON up to 28-50, TOF up to 28-50 h −1 ). 5 As described in subsequent publications by Nolan et al, complex 1 ( Fig.…”

The influence of ion effects on the Pd-catalyzed hydrodechlorination of 4-chlorophenol in aqueous solutions

“…Heterogeneously catalytic hydrogenation is a convenient method for the dehalogenation of aryl halides in organic synthesis because of its experimental simplicity, good yields and high purity of products [1]. In recent years, because the disposal of chlorinated organic waste becomes a serious environmental problem, the catalytic hydrogenolysis of organochlorines has been developed an effective, low cost and environmentally friendly procedure in the environmental catalysis, which has been applied to different types of chlorinated compounds such as chlorobenzenes, chlorophenols, halogenated hydrocarbons, polychlorobiphenyls (PCBs), dioxins etc., leading to their conversion into much less harmful substances under relatively mild conditions [2][3][4][5][6][7][8][9][10][11].…”

“…For most hydrogenation reactions of aromatic halides in liquid phase in reported literatures, organic solvents were usually used as the reaction mediums [1,12,13]. Compared to organic solvents, water is a cheaper, safer and more environmentally amicable reaction medium.…”