Mechanism and cis/trans Selectivity of Vinylogous Nazarov-type [6 pi] Photocyclizationst

Author(s)

Pusch, Stefan ^[1] ; Troester, Andreas ^{[2, 3]} ; Lefrancois, Daniel ^[4] ; Farahani, Pooria ^[5] ; Dreuw, Andreas ^[4] ; Bach, Thorsten ^{[2, 3]} ; Opatz, Till ^[1]

Affiliation

^[1] Johannes Gutenberg Univ Mainz, Inst Organ Chem, Duesbergweg 10-14, D-55128 Mainz - Germany

^[2] Tech Univ Munich, Dept Chem, Lichtenbergstr 4, D-85747 Garching - Germany

^[3] Tech Univ Munich, CRC, Lichtenbergstr 4, D-85747 Garching - Germany

^[4] Ruprecht Karls Univ Heidelberg, Interdisciplinary Ctr Sci Comp, Neuenheimer Feld 205A, D-69120 Heidelberg - Germany

^[5] Univ Sao Paulo, Dept Quim Fundamental, Inst Quim, BR-05508000 Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: Journal of Organic Chemistry; v. 83, n. 2, p. 964-972, JAN 19 2018.
• Web of Science Citations: 3

Abstract

Vinylogous Nazarov-type cyclizations yield seven-membered rings from butadienyl vinyl ketones via a photochemical {[}6 pi] 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. (AU)

• FAPESP's process: 15/02314-8 - Theoretical and experimental studies on the chemiexcitation efficiency of cyclic peroxide decomposition
• Grantee: Pooria Farahani
• Support Opportunities: Scholarships in Brazil - Post-Doctoral