Synthetic and catalytic perspectives of polystyrene supported metal catalyst

The field of organic synthesis is evolving, demanding cleaner, more efficient and selective processes. With a focus on environmental cleanliness, recent years have witnessed remarkable progress in synthesizing and designing molecules, moving away from indiscriminate and wasteful practices. A notable approach involves the use of insoluble polymers and solid-supported agents. By employing suitably functionalized polymer supports, the concept of selectively capturing, filtering, and releasing the desired product in a pure form has emerged as a crucial need. While solid-supported reagents have a history in organic synthesis, recent advancements have introduced numerous improved reagents, many of which are commercially available. The appeal of solid-supported reagents lies in their ability to drive reactions to completion by using excess reagents. Simple filtration for product removal ensures clean chemistry, with the added benefit of isolating the solid-supported species. This isolation proves crucial in cases where the reagent acts as a catalyst or when spent materials can be regenerated and recycled. The attractiveness of this approach extends to immobilizing toxic reagents, enhancing their safety and acceptability by preventing their release into solution. Multiple reagents can be used simultaneously, and site isolation allows incompatible species to coexist, enabling unique one-pot transformations. Thus, a search for sustainable catalytic methods has intensified in recent times as a result of a need for environmentally friendly systems with high activity, efficiency, and selectivity. Heterogeneous catalysts have emerged as a significant field in the synthesis of crucial molecules, due to their improved thermal stability, selectivity, and recyclability. However, drawbacks such as metal leaching and reduced enantioselectivity for asymmetric synthesis persist. This review aims to shed light on the preparation of polymer-supported ligands and their heterogeneous catalytic system by exploring the synthetic methods used to attach ligands and metal complexes to polymer supports. The review emphasizes the diverse range of applications for the supported complexes, providing a comprehensive analysis of their scope and impact.