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Olefin Metathesis with Ru-Based Catalysts Exchanging the Typical N-Heterocyclic Carbenes by a Phosphine–Phosphonium Ylide

Density functional theory (DFT) calculations have been used to describe the first turnover of an olefin metathesis reaction calling for a new in silico family of homogenous Ru-based catalysts bearing a phosphine–phosphonium ylide ligand, with ethylene as a substrate. Equal to conventional Ru-based catalysts bearing an N-heterocyclic carbene (NHC) ligand, the activation of these congeners occurs through a dissociative mechanism, with a more exothermic first phosphine dissociation step. In spite of a stronger electron-donating ability of a phosphonium ylide C-ligand with respect to a diaminocarbene analogue, upper energy barriers were calculated to be on average ca. 5 kcal/mol higher than those of Ru–NHC standards. Overall, the study also highlights advantages of bidentate ligands over classical monodentate NHC and phosphine ligands, with a particular preference for the cis attack of the olefin. The new generation of catalysts is constituted by cationic complexes potentially soluble in water, to be compared with the typical neutral Ru–NHC ones

Albert Poater thanks the Spanish Ministry of Economy and Competitiveness (MINECO) for a project CTQ2014-59832-JIN and Xarxa de Química Teòrica i Computacional for a VALCHEM2016 project

MDPI (Multidisciplinary Digital Publishing Institute)

Manager: Ministerio de Economía y Competitividad (Espanya)
Author: Arnedo Marimon, Laia
Chauvin, Remi
Poater Teixidor, Albert
Date: 2017
Abstract: Density functional theory (DFT) calculations have been used to describe the first turnover of an olefin metathesis reaction calling for a new in silico family of homogenous Ru-based catalysts bearing a phosphine–phosphonium ylide ligand, with ethylene as a substrate. Equal to conventional Ru-based catalysts bearing an N-heterocyclic carbene (NHC) ligand, the activation of these congeners occurs through a dissociative mechanism, with a more exothermic first phosphine dissociation step. In spite of a stronger electron-donating ability of a phosphonium ylide C-ligand with respect to a diaminocarbene analogue, upper energy barriers were calculated to be on average ca. 5 kcal/mol higher than those of Ru–NHC standards. Overall, the study also highlights advantages of bidentate ligands over classical monodentate NHC and phosphine ligands, with a particular preference for the cis attack of the olefin. The new generation of catalysts is constituted by cationic complexes potentially soluble in water, to be compared with the typical neutral Ru–NHC ones
Albert Poater thanks the Spanish Ministry of Economy and Competitiveness (MINECO) for a project CTQ2014-59832-JIN and Xarxa de Química Teòrica i Computacional for a VALCHEM2016 project
Format: application/pdf
Document access: http://hdl.handle.net/10256/13739
Language: eng
Publisher: MDPI (Multidisciplinary Digital Publishing Institute)
Collection: info:eu-repo/semantics/altIdentifier/doi/10.3390/catal7030085
info:eu-repo/semantics/altIdentifier/eissn/2073-4344
info:eu-repo/grantAgreement/MINECO//CTQ2014-59832-JIN/ES/ESCANEO COMPUTACIONAL DE RELACIONES ESTRUCTURA%2FACTIVIDAD DE CATALIZADORES DE OXIDACION DEL AGUA PARA LA GENERACION DE H2/
Rights: Attribution 4.0 Spain
Rights URI: http://creativecommons.org/licenses/by/4.0/es/
Subject: Metàtesi (Química)
Metathesis (Chemistry)
Ruteni
Ruthenium
Mecanismes de reacció (Química)
Reaction mechanisms (Chemistry)
Funcional de densitat, Teoria del
Density functionals
Title: Olefin Metathesis with Ru-Based Catalysts Exchanging the Typical N-Heterocyclic Carbenes by a Phosphine–Phosphonium Ylide
Type: info:eu-repo/semantics/article
Repository: DUGiDocs

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