Heterogeneous photocatalysed Heck reaction over PdCl2/TiO2

Abstract

The heterogeneous PdCl₂/TiO₂ efficiently catalyzes the C–C bond formation (Heck reaction) between aryliodides and olefins under photochemical and mild reaction conditions. This process gives good to excellent conversion under optimized reaction conditions. After completion of the reaction, Pd²⁺ is reduced to Pd⁰. Further, Pd⁰ can be easily converted into Pd²⁺ by heating with ammonium chloride at 400 °C for 30 min and the regenerated catalyst could be reused up to the third recycle with good catalytic activity. The catalysts (before and after reaction, as well as regenerated) were systematically characterized using Transmission Electron Microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, temperature programmed reduction and DRUV-visible spectroscopy techniques.