Mechanism and cis/trans Selectivity of Vinylogous Nazarov-type [6π] Photocyclizations

• Verfasst von: Pusch, Stefan [VerfasserIn]
• Verfasst von: Lefrancois, Daniel [VerfasserIn]
• Verfasst von: Dreuw, Andreas [VerfasserIn]
• Titel: Mechanism and cis/trans Selectivity of Vinylogous Nazarov-type [6π] Photocyclizations
• Verf.angabe: Stefan Pusch, Andreas Tröster, Daniel Lefrancois, Pooria Farahani, Andreas Dreuw, Thorsten Bach, and Till Opatz
• Jahr: 2018
• Jahr des Originals: 2017
• Umfang: 9 S.
• Fussnoten: Published: December 22, 2017 ; Gesehen am 15.05.2020
• Titel Quelle: Enthalten in: The journal of organic chemistry
• Ort Quelle: [S.l.] : American Chemical Society, 1936
• Jahr Quelle: 2018
• Band/Heft Quelle: 83(2018), 2, Seite 964-972
• ISSN Quelle: 1520-6904
• DOI: doi:10.1021/acs.joc.7b02982
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1698357176

Abstract

Vinylogous Nazarov-type cyclizations yield seven-membered rings from butadienyl vinyl ketones via a photochemical [6π] photocyclization followed by subsequent isomerization steps. The mechanism of this recently developed method was investigated using unrestricted DFT, SF-TDDFT, and CASSCF/NEVPT2 calculations, suggesting three different pathways that lead either to pure trans, pure cis, or mixed cis/trans configured products. Singlet biradicals or zwitterions occur as intermediates. The computational results are supported by deuterium-labeling experiments.