Halide Abstraction Competes with Oxidative Addition in the Reactions of Aryl Halides with [Ni(PMePh)]
Funes-Ardoiz, Ignacio (Institut Català d'Investigació Química)
Nelson, David J. (University of Strathclyde)
Maseras Cuní, Feliu (Universitat Autònoma de Barcelona. Departament de Química)

Fecha:	2017
Resumen:	Density functional theory (DFT) calculations have been used to study the oxidative addition of aryl halides to complexes of the type [Ni(PMePh)], revealing the crucial role of an open-shell singlet transition state for halide abstraction. The formation of Ni I versus Ni II has been rationalised through the study of three different pathways: (i) halide abstraction by [Ni(PMePh)], via an open-shell singlet transition state; (ii) S2-type oxidative addition to [Ni(PMePh)], followed by phosphine dissociation; and (iii) oxidative addition to [Ni(PMePh)]. For the overall reaction between [Ni(PMe)], PhCl, and PhI, a microkinetic model was used to show that our results are consistent with the experimentally observed ratios of Ni I and Ni II when the PEt complex is used. Importantly, [Ni(PMePh)] complexes often have little, if any, role in oxidative addition reactions because they are relatively high in energy. The behaviour of [Ni(PR)] complexes in catalysis is therefore likely to differ considerably from those based on diphosphine ligands in which two coordinate Ni 0 complexes are the key species undergoing oxidative addition.
Ayudas:	Ministerio de Economía y Competitividad CTQ2014-57761-R Ministerio de Economía y Competitividad SEV-2013-0319 Ministerio de Economía y Competitividad SVP-2014-068662
Derechos:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Lengua:	Anglès
Documento:	Article ; recerca ; Versió publicada
Materia:	Density functional calculations ; Electron transfer ; Homogeneous catalysis ; Ligand effects ; Nickel
Publicado en:	Chemistry (Weinheim), Vol. 23, Issue 66 (November 2017) , p. 16728-16733, ISSN 1521-3765

DOI: 10.1002/chem.201702331
PMID: 29053182

6 p, 1.4 MB

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