The carbocation-catalyzed intermolecular formal [2 + 2 + 1] cycloaddition of ynamides with quinoxaline N-oxides

• Verfasst von: Jin, Hongming [VerfasserIn]
• Verfasst von: Rudolph, Matthias [VerfasserIn]
• Verfasst von: Rominger, Frank [VerfasserIn]
• Verfasst von: Hashmi, A. Stephen K. [VerfasserIn]
• Titel: The carbocation-catalyzed intermolecular formal [2 + 2 + 1] cycloaddition of ynamides with quinoxaline N-oxides
• Verf.angabe: Hongming Jin, Matthias Rudolph, Frank Rominger, and A. Stephen K. Hashmi
• E-Jahr: 2019
• Jahr: November 4, 2019
• Umfang: 6 S.
• Fussnoten: Gesehen am 13.01.2020
• Titel Quelle: Enthalten in: American Chemical SocietyACS catalysis
• Ort Quelle: Washington, DC : ACS, 2011
• Jahr Quelle: 2019
• Band/Heft Quelle: 9(2019), 12, Seite 11663-11668
• ISSN Quelle: 2155-5435
• DOI: doi:10.1021/acscatal.9b03911
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1687161852

Abstract

Carbocation-catalyzed oxidative [2 + 2 + 1] annulation of two molecules of ynamide with 2,3-dichloroquinoxaline N-oxide enables the facile and convergent assembly of fully substituted symmetric and unsymmetric furan frameworks. The quinoxaline N-oxide presented a remarkable discrepancy to common quinoline and pyridine N-oxides. A wide range of functional groups is well compatible due to the mild conditions. The strategy works also for the intramolecular macrocyclization of diynamides for the synthesis of macrocyclic furan derivatives. Moreover, a set of NMR experiments revealed the activation of a triple bond via a carbocation catalyst.