Organic reaction in water. Part 2. A new method for dechlorination of chlorobiphenyls using a Raney NiAl alloy in dilute aqueous alkaline solution

Zn dust mediated reductive debromination of tetrabromobisphenol A (TBBPA)

“…As a part of our program to develop new ways of degrading hazardous wastes and in order to look for new reaction conditions for a simpler degradation of TBBPA [17,18], the authors would like to report their results on the reductive debromination of TBBPA with zinc dust. Traditionally, for the dehalogenation of alkyl and/or aryl halides, low-valent metals have been used frequently.…”

Raney Ni–Al alloy-mediated reduction of alkylated phenols in water

“…In the continuation of our work on the reduction of halogenated aromatic compounds, [24][25][26][27] we have found that Raney Ni-Al alloy in a dilute aqueous alkaline solution reported that chlorinated or brominated phenols are reduced easily to cyclohexanols with Raney-Ni alloy, 28 and we have now found that non-halogenated, alkylated phenols undergo the reaction with ease. The reductions were carried out by adding an aqueous alkaline solution dropwise to a suspension of a phenol and Raney Ni-Al alloy (350 mg/mmol of substrate) in water at 90°C.…”

Applicability of Nickel-Based Catalytic Systems for Hydrodehalogenation of Recalcitrant Halogenated Aromatic Compounds

“…This alloy contains 50 wt% of Al and 50 wt% of Ni bound in the form of Al 3 Ni and Al 3 Ni 2 . Different bases such as NaOH or KOH [88][89][90][91][92][93][94][95][96][97][98][99][100][101][102][103][104], alkali metal carbonates [89,94,95], NaF [100] or some alkaline salts of complexing agents [91,101] were proved for HDH processes. It was observed that Raney Al-Ni alloy is, especially in diluted aq.…”

“…It was observed that Raney Al-Ni alloy is, especially in diluted aq. NaOH or KOH, a very effective and universal HDH agent enabling quantitative HDH of Ar-Br, Ar-Cl compounds at elevated temperature [89,90,95,96,99,102,104] or even at room temperature [81][82][83][84][85][86][87][88][89][90][91][92][93][94]98,103].…”

“…HDH is accompanied by reduction of other reducible functional groups, carbon-carbon bond cleavage or hydrogenation of aromatic ring, especially at elevated temperature. HDH of chlorobiphenyls produces biphenyl together with phenylcyclohexane [95,97] using excess of Al-Ni at temperature above 60 Ra-Ni is usually more rapid in case of application 20 mg Pd/C under otherwise same reaction conditions. Beside this, the tested catalysts differ in hydrogenolytic scission reactivity of Ar-X.…”