Deactivation of Ru benzylidene Grubbs catalysts active in

Deactivation of ru benzylidene grubbs catalysts active in olefin metathesis

We use cookies to give you the best possible experience on ResearchGate. Read our cookies policy to learn more. It seems we can t find what you re looking for. Perhaps searching, or one of the links below, can help. In this work, we explore the reactivity induced by coordination of a CO molecule trans to the Ru-benzylidene bond of a prototype Ru-olefin metathesis catalyst bearing a N -heterocyclic carbene (NHC) ligand. DFT calculations indicate that CO binding to the Ru center promotes a cascade of reactions with very low-energy barriers that lead to the final crystallographically characterized product, in which the original benzylidene group has attacked the proximal aromatic ring of the ligand leading to a cycloheptatriene ring through a Buchner ring expansion. In conclusion, the overall mechanism is best described as a carbene insertion into a C–C bond of the aromatic N -substituent of the NHC ligand, forming a cyclopropane ring.

This cyclopropanation step is followed by a Buchner ring expansion reaction, leading to the experimentally observed product presenting a cycloheptatriene ring. Dedicated to Professor Vincenzo Barone and published as part of the special collection of articles celebrating his 65th birthday. The research leading to these results has received funding from the European Community’s Seventh Framework Programme (FP7/7557-7568) under grant agreement no CP-FP 766968-7 EUMET.

LC thanks BSC (QCM-7565-7-5575) and the HPC team of Enea for using the ENEA-GRID and the HPC facilities CRESCO in Portici (Italy) for access to remarkable computational resources. 7567 Springer International Publishing AG. Part of Springer Nature.

Ru-complexes relevant to olefin catalysis suffer from deactivation reactions whose mechanism is often difficult to understand. We report here a detailed DFT study showing all the steps that convert the starting complex A into the product B first, and then to evolution of B into product C. Previous article in issue Next article in issue Keywords Homogeneous catalysis Olefin metathesis Computational catalysis Reaction mechanisms Choose an option to locate/access this article:

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Perhaps searching will help find a related post. Perhaps searching can help. A theoretical study of a double C—H activation mechanism that deactivates a family of second generation Ru-based catalysts is presented.

DFT calculations are used to rationalize the complex mechanistic pathway from the starting precatalyst to the experimentally characterized decomposition products. In particular, we show that all the intermediates proposed by Grubbs and coworkers are indeed possible intermediates in the deactivation pathway, although the sequence of steps is somewhat different 7567 Springer International Publishing AG.