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Mechanism of the suzuki-miyaura cross-coupling reaction mediated by [Pd(NHC)(allyl)Cl] Precatalysts

El títol de la versió original de l’article és: "The reaction mechanism of the Suzuki-Miyaura cross-coupling reac-tion. The role of the precatalyst activation"

Density functional theory calculations have been used to investigate the activation mechanism for the precatalyst series [Pd]-X-1-4 derived from [Pd(IPr)(R-allyl)X] species by substitutions at the terminal position of the allyl moiety ([Pd] = Pd(IPr); R = H (1), Me (2), gem-Me 2 (3), Ph (4), X = Cl, Br). Next, we have investigated the Suzuki-Miyaura cross-coupling reaction for the active catalyst species IPr-Pd(0) using 4-chlorotoluene and phenylboronic acid as substrates and isopropyl alcohol as a solvent. Our theoretical findings predict an upper barrier trend, corresponding to the activation mechanism for the [Pd]-Cl-1-4 series, in good agreement with the experiments. They indeed provide a quantitative explanation of the low yield (12%) displayed by [Pd] -Cl-1 species (G 30.0 kcal/mol) and of the high yields (90%) observed in the case of [Pd]-Cl-2-4 complexes (G 20.0 kcal/mol). Additionally, the studied Suzuki-Miyaura reaction involving the IPr-Pd(0) species is calculated to be thermodynamically favorable and kinetically facile. Similar investigations for the [Pd] -Br-1-4 series, derived from [Pd(IPr)(R-allyl)Br], indicate that the oxidative addition step for IPr-Pd(0)-mediated catalysis with 4-bromotoluene is kinetically more favored than that with 4-chlorotoluene. Finally, we have explored the potential of Ni-based complexes [Ni((IPr)(R-allyl)X] (X = Cl, Br) as Suzuki-Miyaura reaction catalysts. Apart from a less endergonic reaction energy profile for both precatalyst activation and catalytic cycle, a steep increase in the predicted upper energy barriers (by 2.0-15.0 kcal/mol) is calculated in the activation mechanism for the [Ni]-X-1-4 series compared to the [Pd] -X-1-4 series. Overall, these results suggest that Ni-based precatalysts are expected to be less active than the Pd-based precatalysts for the studied Suzuki-Miyaura reaction

A.P. thanks the Spanish MINECO for a project CTQ2014-59832-JIN. M.S. thanks EU for a FEDER fund (UNGI08-4E-003), the Generalitat de Catalunya for project 2014SGR931 and ICREA Academia 2014 prize, and MINECO of Spain through project CTQ2014-54306-P

© Organometallics, 2017, vol. 36, núm. 11, p. 2088-2095

American Chemical Society (ACS)

Manager: Ministerio de Economía y Competitividad (Espanya)
Author: Meconi, Giulia Magi
Vummaleti, Sai Vikrama Chaitanya
Luque Urrutia, Jesús Antonio
Belanzoni, Paola
Nolan, Steven P.
Jacobsen, Heiko
Cavallo, Luigi
Solà i Puig, Miquel
Poater Teixidor, Albert
Date: 2017 May 24
Abstract: El títol de la versió original de l’article és: "The reaction mechanism of the Suzuki-Miyaura cross-coupling reac-tion. The role of the precatalyst activation"
Density functional theory calculations have been used to investigate the activation mechanism for the precatalyst series [Pd]-X-1-4 derived from [Pd(IPr)(R-allyl)X] species by substitutions at the terminal position of the allyl moiety ([Pd] = Pd(IPr); R = H (1), Me (2), gem-Me 2 (3), Ph (4), X = Cl, Br). Next, we have investigated the Suzuki-Miyaura cross-coupling reaction for the active catalyst species IPr-Pd(0) using 4-chlorotoluene and phenylboronic acid as substrates and isopropyl alcohol as a solvent. Our theoretical findings predict an upper barrier trend, corresponding to the activation mechanism for the [Pd]-Cl-1-4 series, in good agreement with the experiments. They indeed provide a quantitative explanation of the low yield (12%) displayed by [Pd] -Cl-1 species (G 30.0 kcal/mol) and of the high yields (90%) observed in the case of [Pd]-Cl-2-4 complexes (G 20.0 kcal/mol). Additionally, the studied Suzuki-Miyaura reaction involving the IPr-Pd(0) species is calculated to be thermodynamically favorable and kinetically facile. Similar investigations for the [Pd] -Br-1-4 series, derived from [Pd(IPr)(R-allyl)Br], indicate that the oxidative addition step for IPr-Pd(0)-mediated catalysis with 4-bromotoluene is kinetically more favored than that with 4-chlorotoluene. Finally, we have explored the potential of Ni-based complexes [Ni((IPr)(R-allyl)X] (X = Cl, Br) as Suzuki-Miyaura reaction catalysts. Apart from a less endergonic reaction energy profile for both precatalyst activation and catalytic cycle, a steep increase in the predicted upper energy barriers (by 2.0-15.0 kcal/mol) is calculated in the activation mechanism for the [Ni]-X-1-4 series compared to the [Pd] -X-1-4 series. Overall, these results suggest that Ni-based precatalysts are expected to be less active than the Pd-based precatalysts for the studied Suzuki-Miyaura reaction
A.P. thanks the Spanish MINECO for a project CTQ2014-59832-JIN. M.S. thanks EU for a FEDER fund (UNGI08-4E-003), the Generalitat de Catalunya for project 2014SGR931 and ICREA Academia 2014 prize, and MINECO of Spain through project CTQ2014-54306-P
Format: application/pdf
Citation: https://doi.org/10.1021/acs.organomet.7b00114
ISSN: 0276-7333 (versió paper)
1520-6041 (versió electrònica)
Document access: http://hdl.handle.net/10256/14359
Language: eng
Publisher: American Chemical Society (ACS)
Collection: MINECO/PE 2015-2018/CTQ2014-59832-JIN
MINECO/PE 2015-2017/CTQ2014-54306-P
Versió postprint del document publicat a: 10.1021/acs.organomet.7b00114
Articles publicats (D-Q)
Is part of: © Organometallics, 2017, vol. 36, núm. 11, p. 2088-2095
Rights: Tots els drets reservats
Subject: Funcional de densitat, Teoria del
Density functionals
Activació (Química)
Activation (Chemistry)
Catàlisi
Catalysis
Title: Mechanism of the suzuki-miyaura cross-coupling reaction mediated by [Pd(NHC)(allyl)Cl] Precatalysts
Type: info:eu-repo/semantics/article
Repository: DUGiDocs

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