Modification of silica-supported tungsten neosilyl oxo precatalysts: impact of substituted phenol on activity and stability in olefin metathesisElectronic supplementary information (ESI) available. See DOI: 10.1039/c6cy01812b

• Main Authors: Bouhoute, Y, Del Rosal, I, Szeto, K. C, Merle, N, Grekov, D, De Mallmann, A, Le Roux, E, Delevoye, L, Gauvin, R. M, Maron, L, Taoufik, M
• Format: Article
• Language: English
• ISSN: 2044-4753; 2044-4761
• DOI: 10.1039/c6cy01812b

A novel strategy to access a large variety of tungsten oxo pre-catalysts for olefin metathesis involving post-treatment of [(&z.tbd;SiO)W(&z.dbd;O)(CH 2 SiMe 3 ) 3 ], 1b , with the desired spectator ligands is presented. This method allowed establishing structure-reactivity relationships in propylene metathesis as a function of the spectator ligands of tungsten oxo species. Thus, the novel pre-catalysts [(&z.tbd;SiO)W(&z.dbd;O)R 2 X], 2a-c (X = 2,6-dimethylphenoxide, 2-trifluoromethylphenoxide, pentafluorophenoxide), are obtained by modification of well-defined monopodal species 1b by substituted phenols along with TMS release. These were demonstrated by mass balance analysis, elemental analysis, IR, advanced solid-state NMR (1D and 2D 1 H, 13 C and 19 F) and EXAFS. The modified materials were proved to lead to stable and efficient supported tungsten oxo catalysts for propene metathesis under dynamic conditions at 80 °C. Development of a novel and convenient strategy to access a large variety of highly active tungsten oxo olefin metathesis pre-catalysts.