Veronika Zinovyeva - Highly-Dispersed Palladium-Polypyrrole Nanocomposites Pd@PPy: "in-Water" Synthesis and Application for Catalytic Arylation of Heteroaromatics by Direct C-H Bond Activation

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      Publication Details (including relevant citation   information):

      Adv.   Funct. Mater. 2011,  21,  1064–1075

      Zinovyeva,   Veronika A.;   Vorotyntsev, Mikhail A.; Bezverkhyy, Igor; Chaumont, Denis;   Hierso, Jean-Cyrille.


      Pd@PPy hybrid catalytic materials are synthesized in water via   redox polymerization reaction of pyrrole with   [Pd(NH3)4Cl2]. The   nanocomposites formed are composed of highly dispersed palladium   particles which are either zerovalent or easily reducible, and   are embedded in spherical polypyrrole globules. A unique   combination of high palladium dispersion (NP size: 2.4 nm) and   elevated palladium content (35 wt%) is obtained. The components   of these novel nanocomposites are characterized by means of FTIR,   XPS, XRD, SEM, and TEM microscopy techniques. The process of   formation in solution is also monitored using UV-visible and DLS   techniques. The application of these novel hybrid nanomaterials   in the palladium-catalyzed direct arylation of heteroaromatics is   reported. High efficiency in C–C bond formation is obtained using   these materials. Furans and thiophenes are arylated by using   bromoarenes. Pd@PPy nanocomposites can efficiently couple   n-butyl furan and n-butyl thiophene with   bromobenzene and bromoquinoline, as well as with activated or   deactivated electron-poor and electron-rich functionalized   bromoarenes. Thus, a clean reaction process is developed that   combines the absence of organic ligand in catalytic reactions and   easy recovery of Pd@PPy nanocomposite via simple filtration.   Preliminary kinetic and post-catalysis studies suggest a   molecular or colloidal soluble active species. These very active   species are efficiently delivered by the nanocomposites and   susceptible to a surprisingly uniform back redeposition within   the polypyrrole support.

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