"Polysiloxane-Pd" nanocomposites as recyclable chemoselective hydrogenation catalysts.
Polysiloxane-encapsulated "Pd"-nanoclusters were generated by reduction of Pd(OAc)(2) with polymethylhydrosiloxane, which functions as a reducing agent as well as a capping material for production and stabilization of catalytically active "Pd"-nanoparticles. Chemoselective hydrogenation of functional conjugated alkenes was achieved by in-situ- or ex-situ-generated polysiloxane-stabilized "Pd"-nanoclusters under mild reaction conditions in high yields. Electron microscopy, UV-vis, and NMR studies of the reaction mixture during the catalytic transformation were performed and, in conjunction with catalyst poisoning experiments, demonstrated unequivocally the role of polysiloxane-encapsulated "Pd"-nanoclusters as the real catalytic species. The recyclability of the "Pd"-nanoclusters was established by reusing the solid left after the reaction.
Chauhan
Bhanu P S
BP
Polymers and Engineered Nanomaterials Laboratory, Department of Chemistry and Graduate Center, City University of New York at The College of Staten Island, 2800 Victory Boulevard, Staten Island, New York 10314, USA. chauhan@postbox.csi.cuny.edu
Rathore
Jitendra S
JS
Bandoo
Tariq
T