Mild Copper-Catalyzed Vinylation Reactions of Azoles and Phenols with Vinyl Bromides

✍ Scribed by Marc Taillefer; Armelle Ouali; Brice Renard; Jean-Francis Spindler

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 288 KB
• Volume: 12
• Category: Article
• ISSN: 0947-6539
• DOI: 10.1002/chem.200501411

✦ Synopsis

Abstract

An efficient and straightforward copper‐catalyzed method allowing vinylation of N‐ or __O‐__nucleophiles with di‐ or trisubstituted vinyl bromides is reported. The procedure is applicable to a broad range of substrates since __N‐__vinylation of mono‐, di‐, and triazoles as well as __O‐__vinylation of phenol derivatives can be performed with catalytic amounts of copper iodide and inexpensive nitrogen ligands 3 or 8. In the case of more hindered vinyl bromides, the use of the original bidentate chelator 8 was shown to be more efficient to promote the coupling reactions than our key tetradentate ligand 3. The corresponding N‐(1‐alkenyl)azoles and alkenyl aryl ethers are obtained in high yields and selectivities under very mild temperature conditions (35–110 °C for __N‐__vinylation reactions and 50–80 °C for __O‐__vinylation reactions). Moreover, to our knowledge, this method is the first example of a copper‐catalyzed vinylation of various azoles. Finally, this protocol, practical on a laboratory scale and easily adaptable to an industrial scale, is very competitive compared to the existing methods that allow the synthesis of such compounds.