Selectivity switch in the synthesis of vinylgold(I) intermediates

• Verfasst von: Hashmi, A. Stephen K. [VerfasserIn]
• Verfasst von: Schuster, Andreas M. [VerfasserIn]
• Verfasst von: Gaillard, Sylvain [VerfasserIn]
• Verfasst von: Cavallo, Luigi [VerfasserIn]
• Verfasst von: Poater, Albert [VerfasserIn]
• Verfasst von: Nolan, Steven P. [VerfasserIn]
• Titel: Selectivity switch in the synthesis of vinylgold(I) intermediates
• Verf.angabe: A. Stephen K. Hashmi, Andreas M. Schuster, Sylvain Gaillard, Luigi Cavallo, Albert Poater, and Steven P. Nolan
• E-Jahr: 2011
• Jahr: October 28, 2011
• Umfang: 10 S.
• Illustrationen: Diagramme
• Fussnoten: Gesehen am 07.09.2022
• Titel Quelle: Enthalten in: Organometallics
• Ort Quelle: Washington, DC : ACS Publ., 1982
• Jahr Quelle: 2011
• Band/Heft Quelle: 30(2011), 22, Seite 6328-6337
• ISSN Quelle: 1520-6041
• DOI: doi:10.1021/om2009556
• Datenträger: Online-Ressource
• Sprache: eng
• Bibliogr. Hinweis: Erscheint auch als : Druck-Ausgabe: Selectivity switch in the synthesis of vinylgold(I) intermediates. - 2011
• K10plus-PPN: 1815989424

Abstract

An unexpected regioselectivity reversal was observed in the synthesis of vinylgold(I) complexes from propargyl carboxamides. The use of [Au(IPr)(OH)] affords preferentially vinylgold(I) complexes resulting from a 5-exo-dig cyclization, whereas the use [Au(IPr)]+ species, generated in situ starting from [Au(IPr)(Cl)] and AgOTf, leads to vinylgold(I) complexes which form via a 6-endo-dig cyclization, This unexpected “selectivity switch” for this cyclization led us to propose two different reaction pathways enabling the formation of the two different products. One mechanism involves the [Au(IPr)]+ species with “classical” π activation of the alkyne framework of the carboxamides, and the second represents an “unusual” use of the basic Brønsted character of [Au(IPr)(OH)]. Mechanistic and DFT studies support the mechanistic hypotheses.