Continuous flow systems for hydrogenation using polysilane-supported palladium/alumina (Pd/(PSi-Al(2)O(3))) hybrid catalysts were developed. Our original Pd/(PSi-Al(2)O(3)) catalysts were used successfully in these systems and the hydrogenation of unsaturated C-C bonds and a nitro group, deprotection of a carbobenzyloxy (Cbz) group, and a dehalogenation reaction proceeded smoothly. The catalyst...

[reaction: see text] Kinetics and process parameters of coupling and hydro-dehalogenation reactions of chloroaryls are studied in the presence of zinc, water, and catalytic Pd/C. Good yields are obtained for the coupling of chlorobenzene, 4-chlorotoluene, and 4-chloro-1,1,1-trifluorotoluene. It is shown that water is actually one of the reagents, reacting with zinc in the presence of palladium ...

Catalytic hydrogenation under mild conditions of olefins, unsaturated aldeydes and ketones, nitriles and nitroarenes was investigated, using a supported rhodium complex obtained by copolymerization of Rh(cod)(aaema) [cod: 1,5-cyclooctadiene, aaema-: deprotonated form of 2-(acetoacetoxy)ethyl methacrylate] with acrylamides. In particular, the hydrogenation reaction of halonitroarenes was carried...

We report here a novel and easy-to-handle reductive dehalogenation of 9-bromofluorene in the presence of arylaldehydes and dicarbonyl derivatives to give the corresponding fluorenyl alcohol derivatives and Darzens epoxides as by-products in tetrakis(dimethylamino)ethylene (TDAE) reaction conditions. The reaction is believed to proceed via two successive single electron transfers to generate the...

The chain carrier index (CCI), defined as the ratio of the bond dissociation free energies (BDFE) of corresponding chain carrier halides and hydrides, is proposed as a measure of the thermodynamic efficiency of chain carriers for radical dehalogenation. The larger this value is relative to the corresponding value of the organic substrate, the more thermodynamically efficient the process. The ch...

A competitive PCR (cPCR) assay targeting 16S ribosomal DNA was developed to enumerate growth of a Dehalococcoides-like microorganism, bacterium VS, from a mixed culture catalyzing the reductive dehalogenation of cis-1,2-dichloroethene (cDCE) and vinyl chloride (VC), with hydrogen being used as an electron donor. The growth of bacterium VS was found to be coupled to the dehalogenation of VC and ...

The dehalogenation of a-haloketones and a-halocarbonyl compounds is an inevitable proce­ dure for the organic synthesis and these reductive dehalogenations have been often effected in organic syntheses. There have been various procedures for the purpose and these are obtained by zinc and acetic acid [1], sodium dithionite [2], titanium(III) chloride [3], organotin hydride [4], sodium hydrogen t...