Assembly of Furazan-Fused Quinolines via an Expeditious Metal-Free [2+2+1] Radical Tandem Cyclization Process.

Autor: Deng G; State Key Laboratory of Synthetic Chemistry and Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, P. R. China.; Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research, Ministry of Education, Hunan Normal University, Changsha, Hunan 410081, P. R. China., Zhong R; State Key Laboratory of Synthetic Chemistry and Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, P. R. China., Song J; Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research, Ministry of Education, Hunan Normal University, Changsha, Hunan 410081, P. R. China., Choy PY; State Key Laboratory of Synthetic Chemistry and Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, P. R. China., Kwong FY; State Key Laboratory of Synthetic Chemistry and Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, P. R. China.
Jazyk: angličtina
Zdroj: Organic letters [Org Lett] 2021 Aug 20; Vol. 23 (16), pp. 6520-6524. Date of Electronic Publication: 2021 Aug 09.
DOI: 10.1021/acs.orglett.1c02326
Abstrakt: A [2+2+1]-NO-segment-incorporating heteroannulative cascade is described. This versatile method, particularly using modular cyanoarylated ketimine substrates, allows efficient access to structurally diversified quinolines embedded with an oxadiazole core. This metal-free protocol proceeds smoothly at 30 °C, offers easy manipulation of substituents on the quinoline moiety, and tolerates a spectrum of functional groups. Density functional theory calculation revealed that the cyano moiety is crucial to facilitate the early cyclization step in this heteroannulation process and is different from the previously established late cyclization mechanistic interpretation.
Databáze: MEDLINE
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