Electrophilic Cyclizations of 2-Fluoroalk-3-yn-1-ones: Room-Temperature Synthesis of Diversely 2,5-Disubstituted 3,4-Fluorohalofurans

✍ Scribed by Yan Li; Kraig A. Wheeler; Roman Dembinski

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 230 KB
• Volume: 2011
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/ejoc.201100344

✦ Synopsis

Abstract

A 5‐endo‐dig halocyclization of 2‐fluoroalk‐3‐yn‐1‐ones with the use of N‐iodo‐ and N‐bromosuccinimide, in the presence of gold chloride/zinc bromide (5:20 mol‐%, dichloromethane), under ambient conditions, provides a facile method for the synthesis of 2,5‐disubstituted 3‐bromo‐4‐fluoro‐ and3‐fluoro‐4‐iodofurans. The sequential procedure starts atmonofluorination of the alk‐1‐en‐3‐yn‐1‐yl silyl ethers with Selectfluor and proceeds with good overall yields (62–78 %).