2‐Iminopyridylpalladium dichloride as highly active catalyst for the Heck reaction

Heck reactions of bromoarenes with various olefins catalyzed by 2‐iminopyridylpalladium (II) have been investigated. The scope of a coupling reaction has been tested in 1‐methyl‐2‐pyrrolidinone at 140 °C using K₂CO₃ as base. Using 0.1% molar ratio of palladium catalysts, aryl bromides were converted into 1,2‐substitutedethene products in good to high yields through coupling with both vinylarenes and alkylolefins. With butyl vinyl ether, an electron‐rich olefin, however, the effective coupling reaction produced a mixture of two regio‐isomers, 1,2‐ and 1,1‐substitutedethenes. Copyright © 2007 John Wiley & Sons, Ltd.