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Aryl-copper(III)-acetylides as key intermediates in Csp2-C sp model couplings under mild conditions

The mechanism of copper-mediated Sonogashira couplings (so-called Stephens-Castro and Miura couplings) is not well understood and lacks clear comprehension. In this work, the reactivity of a well-defined aryl-Cu III species (1 ClO 4) with p-R-phenylacetylenes (R=NO2, CF3, H) is reported and it is found that facile reductive elimination from a putative aryl-CuIII-acetylide species occurs at room temperature to afford the Caryl - Csp coupling species (IR), which in turn undergo an intramolecular reorganisation to afford final heterocyclic products containing 2H-isoindole (PNO2, PCF3, PHa) or 1,2-dihydroisoquinoline (PHb) substructures. Density Functional Theory (DFT) studies support the postulated reductive elimination pathway that leads to the formation of C sp2-Csp bonds and provide the clue to understand the divergent intramolecular reorganisation when p-H-phenylacetylene is used. Mechanistic insights and the very mild experimental conditions to effect C aryl-Csp coupling in these model systems provide important insights for developing milder copper-catalysed Caryl - C sp coupling reactions with standard substrates in the future

We acknowledge financial support from European Research Council for Starting Grant Project ERC-2011-StG-277801 to X. R., MICINN of Spain (INNPLANTA project INP-2011-0059-PCT-420000-ACT1 to X. R., CTQ2012-32436 to T. P., CTQ2012-37420-C02-01/BQU to Dr. M. Costas, RyC contract to J.Ll.-F. and PhD FPI grant to M. F.), Consolider-Ingenio CSD2010-00065, and the Catalan DIUE of the Generalitat de Catalunya (2009SGR637). X. R. thanks an ICREA-Academia award

© Chemistry - A European Journal, 2014, vol. 20, p. 10005-10010

Wiley-VCH Verlag

Autor: Rovira Coll, Mireia
Font Molins, Marc
Acuña-Parés, Ferran
Parella Coll, Teodor
Luis Luis, Josep Maria
Lloret Fillol, Julio
Ribas Salamaña, Xavi
Data: 2014
Resum: The mechanism of copper-mediated Sonogashira couplings (so-called Stephens-Castro and Miura couplings) is not well understood and lacks clear comprehension. In this work, the reactivity of a well-defined aryl-Cu III species (1 ClO 4) with p-R-phenylacetylenes (R=NO2, CF3, H) is reported and it is found that facile reductive elimination from a putative aryl-CuIII-acetylide species occurs at room temperature to afford the Caryl - Csp coupling species (IR), which in turn undergo an intramolecular reorganisation to afford final heterocyclic products containing 2H-isoindole (PNO2, PCF3, PHa) or 1,2-dihydroisoquinoline (PHb) substructures. Density Functional Theory (DFT) studies support the postulated reductive elimination pathway that leads to the formation of C sp2-Csp bonds and provide the clue to understand the divergent intramolecular reorganisation when p-H-phenylacetylene is used. Mechanistic insights and the very mild experimental conditions to effect C aryl-Csp coupling in these model systems provide important insights for developing milder copper-catalysed Caryl - C sp coupling reactions with standard substrates in the future
We acknowledge financial support from European Research Council for Starting Grant Project ERC-2011-StG-277801 to X. R., MICINN of Spain (INNPLANTA project INP-2011-0059-PCT-420000-ACT1 to X. R., CTQ2012-32436 to T. P., CTQ2012-37420-C02-01/BQU to Dr. M. Costas, RyC contract to J.Ll.-F. and PhD FPI grant to M. F.), Consolider-Ingenio CSD2010-00065, and the Catalan DIUE of the Generalitat de Catalunya (2009SGR637). X. R. thanks an ICREA-Academia award
Format: application/pdf
ISSN: 0947-6539 (versió paper)
1521-3765 (versió electrònica)
Accés al document: http://hdl.handle.net/10256/10204
Llenguatge: eng
Editor: Wiley-VCH Verlag
Col·lecció: MINECO/PN 2013-2015/CTQ2012-37420-C02-01
MICINN/PN 2010-2016/CSD2010-00065
AGAUR/2009-2014/2009 SGR-637
MICINN/PN 2011/INP-2011-0059-PCT-420000
Reproducció digital del document publicat a: http://dx.doi.org/10.1002/chem.201402711
Articles publicats (D-Q)
info:eu-repo/grantAgreement/EC/FP7/277801
És part de: © Chemistry - A European Journal, 2014, vol. 20, p. 10005-10010
Drets: Tots els drets reservats
Matèria: Compostos organometàl·lics
Organometallic compounds
Coure
Copper
Funcional de densitat, Teoria del
Density functionals
Mecanismes de reacció (Química)
Reaction mechanisms (Chemistry)
Títol: Aryl-copper(III)-acetylides as key intermediates in Csp2-C sp model couplings under mild conditions
Tipus: info:eu-repo/semantics/article
Repositori: DUGiDocs

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