Organic & Inorganic Chemistry

Biography

Biography: Bhanu P S Chauhan

Abstract

In recent years, our laboratory has been investigating new and industrially relevant routes to creating heterogeneous platforms of selectively cross-linked polysiloxanes, in which the metal nanoparticles are nucleated in desired concentration and morphology. We have observed that such ensemble of immobilized nanoparticles can act as highly efficient, mild and recyclable catalysts for hydrolytic oxidation of organosilane, hydrosilylation of olefin and polyolefins. In these cases, the air-stable solid catalyst first forms a homogeneous/dispersed phase with the reactant molecules and separates out at the end of reaction. In this presentation, we will present a mild, predictable, facile and widely applicable Pt-based recyclable platinum nanoparticle catalyzed selective hydrosilylation of mono- and di-substituted alkynes is reported. A variety of hydrosilanes were selectively reacted with alkynes containing diverse functionality including–Me, -Ar, -ArMe, -Ar(OMe), -SiMe3, (CH2)4CN, -ArNH2, -CH2NEt2 and -COOH to furnish corresponding vinylsilanes in high yields. In situ characterization using UV-vis, electron microscopy and controlled poisoning experiments during the reaction has revealed the participation of Pt-nanoparticles as an active catalyst. Whereas, the regio and stereo selectivity of the present nanoparticles catalyst were not very different for the hydrosilylation of certain alkynes reported previously, significant improvement in terms of catalytic efficiency, ease of catalyst recovery and recyclability over other platinum-based catalysts were achieved using polysiloxane stabilized Pt-nanoparticle catalysis. Thus, this catalysis allows one to produce functionalized vinylsilanes in excellent yields with the added advantage of a significant cost improvement over homogeneous platinum complexes.