Phosphine‐NHC Manganese Hydrogenation Catalyst Exhibiting a Non‐Classical Metal‐Ligand Cooperative H2 Activation Mode |
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Authors: | Ruqaya Buhaibeh Oleg A Filippov Antoine Bruneau‐Voisine Jrmy Willot Carine Duhayon Dmitry A Valyaev Noël Lugan Yves Canac Jean‐Baptiste Sortais |
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Institution: | Ruqaya Buhaibeh,Oleg A. Filippov,Antoine Bruneau‐Voisine,Jérémy Willot,Carine Duhayon,Dmitry A. Valyaev,Noël Lugan,Yves Canac,Jean‐Baptiste Sortais |
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Abstract: | Deprotonation of the MnI NHC‐phosphine complex fac‐MnBr(CO)3(κ2P,C‐Ph2PCH2NHC)] ( 2 ) under a H2 atmosphere readily gives the hydride fac‐MnH(CO)3(κ2P,C‐Ph2PCH2NHC)] ( 3 ) via the intermediacy of the highly reactive 18‐e NHC‐phosphinomethanide complex fac‐Mn(CO)3(κ3P,C,C‐Ph2PCHNHC)] ( 6 a ). DFT calculations revealed that the preferred reaction mechanism involves the unsaturated 16‐e mangana‐substituted phosphonium ylide complex fac‐Mn(CO)3(κ2P,C‐Ph2P=CHNHC)] ( 6 b ) as key intermediate able to activate H2 via a non‐classical mode of metal‐ligand cooperation implying a formal λ5‐P–λ3‐P phosphorus valence change. Complex 2 is shown to be one of the most efficient pre‐catalysts for ketone hydrogenation in the MnI series reported to date (TON up to 6200). |
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Keywords: | DFT-Rechnungen Mangan Metall-Liganden-Kooperation N-heterozyklische Carbene Phosphoniumylide |
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