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Carbon supported hybrid catalysts for controlled product selectivity in the hydrosilylation of alkynes

Journal Article


Abstract


  • A series of Rh- and Ir-hybrid catalysts with varying tether lengths has been prepared by immobilization of RhI, RhIIIand IrIIIcomplexes on carbon blackviaradical grafting. The performance of the different catalysts was assessed for the hydrosilylation of phenylacetylene with Et3SiH. The efficiency of the catalysts was dependent on the length of the tethers to the surface. The RhIII- and IrIIIhybrids afforded the β(Z)-vinylsilanes, as observed for the analogous homogeneous RhIIIcatalyst. No distinct product selectivity was observed when using the homogeneous RhIprecursors as catalysts. However, on using the RhIIIhybrid catalysts derived from the RhIprecursors to promote hydrosilylation, the major products were the α-vinylsilanes and the origin of the difference in reactivity was found to be a chemical modification of the catalysts during immobilization. Substrate scope is demonstrated for a number of alkynes, and feasible mechanisms supported by DFT calculations are proposed.

Publication Date


  • 2021

Citation


  • Roemer, M., Gonçales, V. R., Keaveney, S. T., Pernik, I., Lian, J., Downes, J., . . . Messerle, B. A. (2021). Carbon supported hybrid catalysts for controlled product selectivity in the hydrosilylation of alkynes. Catalysis Science and Technology, 11(5), 1888-1898. doi:10.1039/d0cy02136a

Scopus Eid


  • 2-s2.0-85102951156

Start Page


  • 1888

End Page


  • 1898

Volume


  • 11

Issue


  • 5

Abstract


  • A series of Rh- and Ir-hybrid catalysts with varying tether lengths has been prepared by immobilization of RhI, RhIIIand IrIIIcomplexes on carbon blackviaradical grafting. The performance of the different catalysts was assessed for the hydrosilylation of phenylacetylene with Et3SiH. The efficiency of the catalysts was dependent on the length of the tethers to the surface. The RhIII- and IrIIIhybrids afforded the β(Z)-vinylsilanes, as observed for the analogous homogeneous RhIIIcatalyst. No distinct product selectivity was observed when using the homogeneous RhIprecursors as catalysts. However, on using the RhIIIhybrid catalysts derived from the RhIprecursors to promote hydrosilylation, the major products were the α-vinylsilanes and the origin of the difference in reactivity was found to be a chemical modification of the catalysts during immobilization. Substrate scope is demonstrated for a number of alkynes, and feasible mechanisms supported by DFT calculations are proposed.

Publication Date


  • 2021

Citation


  • Roemer, M., Gonçales, V. R., Keaveney, S. T., Pernik, I., Lian, J., Downes, J., . . . Messerle, B. A. (2021). Carbon supported hybrid catalysts for controlled product selectivity in the hydrosilylation of alkynes. Catalysis Science and Technology, 11(5), 1888-1898. doi:10.1039/d0cy02136a

Scopus Eid


  • 2-s2.0-85102951156

Start Page


  • 1888

End Page


  • 1898

Volume


  • 11

Issue


  • 5