Addressing polar solvent challenges in the heterogenization of palladium catalysed Hayashi-Miyaura reaction on polymer support

Abstract

The development of recyclable heterogeneous catalysts for the palladium-catalysed additions of arylboronic acids to nitrostyrenes is investigated in this study. Two strategies, direct copolymerization and post-modification, are explored for immobilizing chiral isoquinoline-oxazoline ligands onto polymer matrices. Various copolymer formulations are prepared, and their catalytic activity, recyclability, and reaction kinetics are evaluated. The incorporation of polar functional groups into the polymer matrix enhances catalytic properties, albeit with a decrease in reaction rate compared to the homogeneous system. Post-modification using a polystyrene-polyethylene glycol (PS-PEG) support shows promise, resulting in a moderate decrease in reaction rate and satisfactory performance over multiple reaction cycles. The findings provide valuable insights into the immobilization of chiral ligands and highlight the advantages and limitations of different polymer compositions. These results contribute to the development of advanced catalytic systems for the synthesis of biologically relevant compounds.