Mechanism of the Ru-Allenylidene to Ru-Indenylidene Rearrangement in Ruthenium Precatalysts for Olefin Metathesis

The intramolecular allenylidene RuCl2(PR3)2(C=C=CPh2) to indenylidene RuCl2(PR3)2(Ind) rearrangement that occurs during the synthesis of Ru-based precatalysts for olefin metathesis is presented. In the absence of acid, the ring closure via C-H activation was shown to be unfavored for energy barriers...

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Bibliographic Details
Authors: Pump, Eva, Slugovc, Christian, Cavallo, Luigi, Poater Teixidor, Albert
Format: article
Status:Published version
Publication Date:2015
Country:España
Institution:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repository:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:10256/13298
Online Access:http://hdl.handle.net/10256/13298
Access Level:Embargoed access
Keyword:Metàtesi (Química)
Metathesis (Chemistry)
Alquens
Alkenes
Description
Summary:The intramolecular allenylidene RuCl2(PR3)2(C=C=CPh2) to indenylidene RuCl2(PR3)2(Ind) rearrangement that occurs during the synthesis of Ru-based precatalysts for olefin metathesis is presented. In the absence of acid, the ring closure via C-H activation was shown to be unfavored for energy barriers up to 70 kcal/mol. Thus, it turned out to be HCl (or other acid) that plays a crucial role during formation of the indenylidene, as the upper energy barrier decreases to a reasonable 35 kcal/mol. Moreover, we proved computationally that depending on the nature of the phosphine the intramolecular rearrangement is either facilitated (PPh3) or slightly hampered (PCy3), which is in line with experimental results