Iron(III)-promoted hydrofunctionalization/bicyclization of 1, 7-enynes toward benzo[a]fluoren-5-ones. Issue 7 (13th February 2020)

• Record Type: Journal Article
• Authors: Huang, Min-Hua; Hong, Yu; Hu, Jian-Qiang; Yang, Shi-Zhao; Zhu, Yi-Long; Wang, De-Cai; Jiang, Bo
• Is Part Of: Tetrahedron letters. Volume 61:Issue 7(2020)
• Publication Date: 2020-02-13
• Subjects: Hydrofunctionalization -- Bicyclization -- Benzo[a]fluoren-5-ones -- Radical chemistry; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2019.151507
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: Highlights: A new hydrofunctionalization/bicyclization of C(sp 3 )-tethered 1, 7-enynes is established. The mechanism involves a hydrogen radical induced 6- exo-dig /5- endo-trig bicyclization cascade. This method provides a new entry for the formation of benzo[ a ]fluoren-5-ones. Abstract: A new hydrofunctionalization/bicyclization of C(sp 3 )-tethered 1, 7-enynes toward benzo[ a ]fluoren-5-ones with good to excellent yields has been developed by using Iron(III)/PhSiH3 system as a hydride donor. This protocol involves a reductive 1, 7-enyne-carboannulation cascade, leading to C(sp 3 )H and CC bond-forming events to rapidly build up tetracarbocyclic complexity. A wide range of functional groups relative to 1, 7-enyne substrates were tolerated well under mild neutral-redox conditions.