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

Max Roemer, Vinicius R. Gonçales, Sinead T. Keaveney, Indrek Pernik, Jiaxin Lian, James Downes, J. Justin Gooding, Barbara A. Messerle*

*Corresponding author for this work

Research output: Contribution to journalArticle

Abstract

A series of Rh- and Ir-hybrid catalysts with varying tether lengths has been prepared by immobilization of RhI, RhIII and IrIII complexes on carbon black via radical 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 IrIII hybrids afforded the β(Z)-vinylsilanes, as observed for the analogous homogeneous RhIII catalyst. No distinct product selectivity was observed when using the homogeneous RhI precursors as catalysts. However, on using the RhIII hybrid catalysts derived from the RhI precursors 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.
Original languageUnknown
JournalCatalysis Science and Technology
DOIs
Publication statusE-pub ahead of print - Dec 2020

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