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Abstract Aiming at the enhanced catalytic activity of fluoro‐λ3‐iodane generated from iodoarene precatalyst with Selectfluor and HF⋅pyridine, this study focused on the λ3‐iodanes bearing coordinating substituents. Compared to 4‐iodoanisole as a precatalyst of our previous method,N‐methyl‐2‐iodobenzamide or 2‐iodobenzamide worked well in the fluorocyclization ofN‐propargyl carboxamides to oxazoles. Control experiments suggest the equilibrium mixture of iodane‐amine complexes and cyclic iodane fluorides would be involved in the present catalysis. magnified image
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An Efficient Route to Isochromene Derivatives via Cascade Radical Cyclization and Radical‐Radical Coupling
Abstract Isochromenes are important pharmacophores present in biologically active molecules and natural products. Their synthesis is generally limited to cyclization of phenyl propargyl ether precursors under transition metal catalyzed conditions. Herein, we present a novel disconnection that rapidly constructs isochromene derivatives through a cascade radical cyclization strategy. Generation of aryl radicals by SET reduction of 2‐iodo benzyl allenyl ethers is followed by radical cyclization to construct the isochromene core with formation of an allylic radical. The allylic radical then undergoes coupling with the azaallyl radical to give products in good to excellent yields. The elaborated 2‐iodo phenyl propargyl ether precursors can be used to construct isochromenes bearing various functional groups. magnified image
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- PAR ID:
- 10114005
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Synthesis & Catalysis
- Volume:
- 361
- Issue:
- 18
- ISSN:
- 1615-4150
- Format(s):
- Medium: X Size: p. 4354-4359
- Size(s):
- p. 4354-4359
- Sponsoring Org:
- National Science Foundation
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