%0 Conference Paper %F Poster %T Catalytic hydrogenolysis of silyl triflates to hydrosilanes using iridium pincer complexes %+ Laboratoire de Chimie Moléculaire et de Catalyse pour l'Energie (ex LCCEF) (LCMCE) %A Durin, Gabriel %A Berthet, Jean-Claude %A Nicolas, Emmanuel %A Thuéry, Pierre %A Cantat, Thibault %< avec comité de lecture %B 12th International Scholl on Organometallic Chemistry “Marcial Moreno Mañas” %C Castellon, Spain %8 2019-06-12 %D 2019 %Z Chemical Sciences/Material chemistryPoster communications %X Hydrosilanes are convenient reductants for a large variety of organic oxygenated substratesand they have been successfully applied in the conversion ofbio-based materialsl and C0$_2$At present, hydrosilanes are produced via energy intensive processes and they generate,after use, silicon oxides wastes su ch as siloxanes, which are difficult to recycle. Theselimitations call for the development of catalytic pro cesses able to transform Si-O bonds insiloxanes and derivatives (silyl halides and triflates) into Si-H hydrides.Very recently, the groups of Shimada and Schneider reported for the first time thehydrogenolysis of sorne silyl halides and triflates with iridium(lII) catalysts andruthenium(II). Following these preliminary reports, we studied the catalytic hydrogenolysisof R$_3$SiOTf (R = Me, Et, Ph) species in the presence of a base, by the dihydride complex(POCOP)IrH$_2$ (See figure above). Syntheses and crystal structures of sorne isolated Ir(l) andIr(III) complexes will be presented as well as their role in the R$_3$SiOTf to R$_3$SiHtransformation.The new (POCOP)Ir$^I$(TBD) complex, which splits H$_2$ to (POCOP)Ir$^{III}$H$_2$ at a low pressure, isa pre-catalyst in the hydrogenolysis of Si-OTf linkages. It can be easily obtained from(POCOP)IrHCI, using the TBD guanidine. To the best of our knowledge, such spontaneousreductive elimination by a weak base of an iridium(lII) hydro-chloride species is novel.The kinetic and thermodynamic profiles of the reaction were examined by means ofspectroscopic and DFT studies. The mechanism reveals that rate detennining step is thehydride transfer from (POCOP)IrH$_2$ to the silyl triflate. The base (e.g. NEt$_3$) is required todrive the thermodynalnics of the reaction, by promoting the regeneration of iridium hydridesintennediates, in the presence of H$_2$. %G English %2 https://cea.hal.science/cea-02329217/document %2 https://cea.hal.science/cea-02329217/file/Durin_EICO2019.pdf %L cea-02329217 %U https://cea.hal.science/cea-02329217 %~ CEA %~ CNRS %~ PUBNIMBE %~ DSV %~ INC-CNRS %~ IRAMIS-NIMBE %~ CEA-UPSAY %~ UNIV-PARIS-SACLAY %~ CEA-UPSAY-SACLAY %~ CEA-DRF %~ TEST-HALCNRS %~ GS-ENGINEERING %~ IRAMIS %~ GS-CHIMIE %~ GS-PHYSIQUE %~ INSTITUT-SCIENCES-LUMIERE %~ TEST2-HALCNRS