Polymer-Supported Bis-1,2,4-triazolium Ionic Tag Framework for an Efficient Pd(0) Catalytic System in Biomass Derived γ-Valerolactone

A resin-bound 1,2,4-triazolium ionic tag has been used as support for the preparation of solid palladium nanoparticles (Pd(0)-POLI-TAG-Pd). Owing to the pincer-type architecture of the triazolium ligand, the stabilization of a high amount of palladium nanoparticles (16 wt %) has been possible. The catalytic system has been fully characterized and used in low amounts (i.e., 0.1 mol % palladium loading) in representative Heck-Mizoroki cross-coupling processes. A negligible release of the metal was demonstrated, and a high activity was obtained over more runs. Besides, the protocol has been optimized for the use of safe biomass-derived gamma-valerolactone reaction medium.