Visible-light-induced cascade radical ring-closure and pyridylation for the synthesis of tetrahydrofurans. Issue 8 (25th March 2019)

• Record Type: Journal Article
• Authors: Kim, Yechan; Lee, Kangjae; Mathi, Gangadhar Rao; Kim, Inwon; Hong, Sungwoo
• Is Part Of: Green chemistry. Volume 21:Issue 8(2019)
• Page Start: 2082
• Page End: 2087
• Publication Date: 2019-03-25
• Subjects: Environmental chemistry -- Industrial applications -- Periodicals; Environmental management -- Periodicals; 660
• DOI: 10.1039/c9gc00414a
• Languages: English
• ISSNs: 1463-9262

Abstract

Abstract : A novel visible-light-enabled alkoxy radical ring-closure and pyridylation from N -alkenyloxypyridinium salts was achieved under metal-free mild conditions, offering a powerful synthetic tool for assembling various pyridine-tethered tetrahydrofurans. Abstract : Reported is a novel visible-light-enabled alkoxy radical ring-closure and pyridylation from N -alkenyloxypyridinium salts serving as both alkoxy radical precursors and heteroaryl sources. This strategy features a photoredox tandem radical process involving a sequential fragmentation of an N -alkoxypyridinium salt, a radical cyclization process, and a pyridylation process. This method exhibited broad substrate scope, good functional group compatibility, and metal-free mild conditions, offering a powerful synthetic tool for assembling various pyridine-tethered tetrahydrofurans and late-stage functionalization of complex biorelevant molecules. Moreover, radical cascade cyclization could be successfully achieved, leading to the synthesis of previously challenging and important pyridine-tethered bicyclic oxaspiro ring systems.