Iridium Tetra(4-carboxyphenyl) Porphyrin, Calix[4]pyrrole and Tetraphenyl Porphyrin Complexes as Potential Hydrogenation Catalysts

Abstract

Here we report the preparation of first examples of iridium-based organometallic macromolecules, viz., iridium-tetra (4-carboxyphenyl)porphyrin (IrTCPP), iridium-calix[4]pyrrole (IrCP) iridium-tetraphenylporphyrin (IrTPP), which are effective catalysts for hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) and 1,4-pentanediol under base free conditions. The turnover number in the range of 1220–2850 is evident for the chosen reaction using iridium macromolecule based catalysts. The heterogenization of homogeneous IrTCPP, IrCP, and IrTPP result in stable reactivity of the catalysts for several runs.