Divergence in Ynone Reactivity: Atypical Cyclization by 3,4-Difunctionalization versus Rare Bis(cyclization).

Autor: Alcaide B; Grupo de Lactamas y Heterociclos Bioactivos, Departamento de, Química Orgánica I, Unidad Asociada al CSIC, Facultad de Química, Universidad Complutense de Madrid, 28040, Madrid, Spain., Almendros P; Instituto de Química Orgánica General, Consejo Superior de Investigaciones Científicas, IQOG-CSIC, Juan de la Cierva 3, 28006, Madrid, Spain., Lázaro-Milla C; Grupo de Lactamas y Heterociclos Bioactivos, Departamento de, Química Orgánica I, Unidad Asociada al CSIC, Facultad de Química, Universidad Complutense de Madrid, 28040, Madrid, Spain., Delgado-Martínez P; CAI Difracción de Rayos X, Facultad de Química, Universidad Complutense de Madrid, Spain.
Jazyk: angličtina
Zdroj: Chemistry (Weinheim an der Bergstrasse, Germany) [Chemistry] 2018 Jun 07; Vol. 24 (32), pp. 8186-8194. Date of Electronic Publication: 2018 May 14.
DOI: 10.1002/chem.201800630
Abstrakt: Functionalized ynones can be activated by Tf 2 C=CH 2 , which was generated in situ, to form zwitterionic species. These species were trapped in an intramolecular fashion by several nucleophiles to generate two major types of triflones in a divergent manner. Through fine-tuning of the reaction temperature, bis(triflyl)-6-membered- or (triflyl)-5-membered-fused-heterocycles were achieved in reasonable yields in a totally selective manner. In this way, bis(triflyl)flavones, bis(triflyl)thioflavones, bis(triflyl)selenoflavones, (triflyl)benzothienopyrans, (triflyl)benzoselenophenopyrans, (triflyl)vinyl aurones, and (triflyl)pyranoindoles were constructed. Conceivable mechanistic pathways were suggested on the basis of the isolation of several intermediates and the results from control experiments.
(© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
Databáze: MEDLINE
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