Pd‐EnCatTM TPP30 as a Catalyst for the Generation of Highly Functionalized Aryl‐ and Alkenyl‐Substituted Acetylenes via Microwave‐Assisted Sonogashira Type Reactions

We report a rapid microwave‐assisted Sonogashira cross‐coupling of aryl iodides and bromides with terminal alkynes using Pd‐EnCatTM TPP30. Both electron‐rich and electron‐deficient aryl halides reacted smoothly with a broad variety of terminal alkynes in MeCN at 100–120 °C. The coupling products were obtained in good to excellent yields and in high purity. This reaction can be performed under copper‐ and DMF‐free conditions and does not require an inert atmosphere. Furthermore, the encapsulated catalyst can be recovered and recycled by a simple filtration of the reaction mixture. It can be reused in further reactions with only minor decrease in activity. Additionally, we were able to produce a variety of enyne derivatives under modified conditions employing the same Pd‐EnCatTM source. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) Without using any copper species and under robust conditions, rapid microwave‐assisted Sonogashira cross‐coupling of aryl iodides and bromides with terminal alkynes using Pd‐EnCatTM TPP30 were conducted. Both electron‐rich and electron‐deficient aryl halides reacted smoothly with a broad variety of terminal alkynes in MeCN at 100–120 °C.