Cellulose/silica supported Schiff base Pd(II) catalyst for copper-free Sonogashira cross-coupling

In present investigation, a cellulose/silica supported Schiff base Pd(II) catalyst, acronym as Cell/SiO 2 -Sal-Pd(II), has been designed and synthesized using cellulose as support. The catalyst was comprehensively characterized by advanced techniques such as FTIR, XRD, TGA, SEM, EDS, and BET/BJH. From the EDX analysis, the loading of palladium found to be 0.017 mol%. TEM analysis revealed ~ 70 nm particle size of the catalyst. The catalytic efficiency of Cell/SiO 2 -Sal-Pd(II) was thoroughly scrutinized in the context of the Sonogashira cross-coupling. Varity of functionalized diary acetylene derivatives have been achieved with admirable yields from coupling of aryl halides and phenyl acetylenes. The XRD, SEM and TGA analysis of recycled catalyst revealed remarkable catalytic activity. The proposed approach exhibits remarkable merits such as impressively low catalyst loading (0.009 mol%), elevated turnover numbers (up to 10,556), commendable turnover frequencies (up to 3519), exceptional thermal stability (up to 356.75 °C), high surface area (94.825 m 2 /g), superior catalyst reusability (up to 5 times) and the employment of an environmentally friendly aqueous acetonitrile solvent system. Graphical abstract