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 crosscoupling of aryl iodides and bromides with terminal alkynes using Pd-EnCat™ TPP30. Both electron-rich and electrondeficient 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 copperand 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-EnCat™ source.