0000000000383119
AUTHOR
Oleg M. Nikitin
Electrochemically reduced titanocene dichloride as a catalyst of reductive dehalogenation of organic halides
Abstract We have studied a reaction between the reduced form of titanocene dichloride (Cp 2 TiCl 2 ) and a group of organic halides: benzyl derivatives (4-X C 6 H 4 CH 2 Cl, X = H, NO 2 , CH 3 ; 4-X C 6 H 4 CH 2 Br, X = H, NO 2 , PhC(O); 4-X C 6 H 4 CH 2 SCN, X = H, NO 2 ) as well as three aryl halides (4-NO 2 C 6 H 4 Hal, Hal = Cl, Br; 4-CH 3 O-C 6 H 4 Cl). It has been shown that the electrochemical reduction of Cp 2 TiCl 2 in the presence of these benzyl halides leads to a catalytic cycle resulting in the reductive dehalogenation of these organic substrates to yield mostly corresponding toluene derivatives as the main product. No dehalogenation has been observed for aryl derivatives. Base…
Palladium nanoparticles–polypyrrole composite as an efficient catalyst for cyanation of aryl halides
Abstract New palladium-polypyrrole (Pd/PPy) nanocomposites have been studied in cyanation of aryl halides with K 4 Fe(CN) 6 and showed high catalytic efficiency. Aryl iodides, bromides, and chlorides are active. The reaction can be performed both in organic solvents and in water; in the latter case, the catalyst was immobilized on graphite support. The cyanation of inactivated aryl chlorides is of special importance as only a few publications dealing with efficient cyanation of aryl chlorides are available, in which expensive and poisonous phosphine ligands and non-aqueous solvents are used. The influence of the morphology of the catalyst on its efficiency in cyanation was investigated, and…
Palladium–Polypyrrole Nanoparticles-Catalyzed Sonogashira Coupling
Abstract Palladium nanoparticles were encapsulated into polypyrrole globules via one-step one-pot redox reaction between tetraamminepal- ladium(ii) dichloride and pyrrole in water. Such a material is an active catalyst for the Sonogashira coupling of iodo- and bromo- arenes.
Polypyrrole–palladium nanoparticles composite as efficient catalyst for Suzuki–Miyaura coupling
International audience; Synthesis of a new hybrid material (Pd/PPy) composed of polypyrrole globules with uniformly incorporated Pd nanoparticles via direct redox reaction between pyrrole and Pd(NH3)(4)Cl-2 in water has been recently reported (V.A. Zinovyeva, M.A.Vorotyntsev, I. Bezverkhyy, D. Chaumont, J.-C. Hierso, Adv. Funct. Mater. 21 (2011) 1064-1075). In the actual study, this procedure has been extended to synthesize a series of Pd/PPy powders with variable palladium content and morphological parameters. Depending on the monomer-to-oxidant ratio in reaction mixture, average diameters of Pd and PPy particles may change in the ranges of 1.25-1.45 and 27-62 nm, respectively, the Pd conc…