NNN Pincer‐functionalized Porous Organic Polymer Supported Ru(III) as a Heterogeneous Catalyst for Levulinic Acid Hydrogenation to γ‐Valerolactone

Abstract A novel porous organic polymer that incorporates NNN pincer type of ligand, i. e., 2,6‐Bis(pyrazol‐3‐yl)pyridine, (3‐bpp‐POP) is prepared via solvent‐knitting method. Through the characterizations, 3‐bpp‐POP is demonstrated to possess abundant porous structure, high surface area, and excellent thermal durability. A ruthenium molecular catalyst immobilized on the 3‐bpp‐POP support exhibits substantial catalytic performance for the hydrogenation of LA to GVL with an initial turnover frequency (TOF) of 1680 h −1 and a maximum turnover number (TON) of 14762 over 24 h for LA conversion with selectivities of 91.1 % for GVL and 8.9 % for HPA. The catalyst demonstrated excellent durability during successive recycles without leaching Ru3+, which ascribe to the strong binding of pincer ligand to metal centers.