Simple synthesis of poly (1,4-bis(dodecyloxy)-2,5-diethynylbenzene)/Pd composites with catalytic activity in Sonogashira coupling reaction

Abstract

Abstract Palladium on the polymeric materials (Pd@polymer) as a catalyst is now very promising due to its great prospect for catalytic application. Such material in the form of composites is found to be stable and can be applied as catalyst in organic synthesis like Sonogashira coupling reaction. In the present work, Pd containing conjugated poly-ynes composites (Poly (1,4-bis(dodecyloxy)-2,5-diethynylbenzene) (Poly-DEB)/Pd) were synthesized by varying the addition of Pd in the range of equivalent weight of 8:4, 8:2 and 8:1, maintaining the fixed amount of 1,4-bis(dodecyloxy)-2,5-diethynylbenzene (DEB) through chemical oxidative polymerization technique. Both FTIR and UV-visible spectroscopy confirmed the interactions between DEB and Pd in the composites. The DSC data revealed the improved melting temperature as well as the crystallinity of the composites than the DEB. The PL spectra showed its florescence property. The catalytic capability of the Poly-DEB/Pd composites were examined using the Sonogashira coupling reactions, which demonstrated good yields. The suggested synthetic protocol is very facile, reproducible and beneficial for the fabrication of diverse mono and bimetallic composites with conjugated polymers. The present study also demonstrates the new example of Poly-DEB/Pd composites catalyzed Sonogashira coupling reaction. These composites have a possibility to develop as a commercial reagent in various organic synthesis subjects to its application prospects.