Tether-Free Immobilized Bifunctional Squaramide Organocatalysts for Batch and Flow Reactions

This paper describes the preparation of highly efficient, easily accessible, and robust immobilized bifunctional organocatalysts. There was no need to employ any tether to secure high enantio- and diastereoselectivities in various Michael addition reactions. The synthetically useful Michael adducts were obtained within reasonable reaction times with the advantage of easy product isolation and the possibility of automation by using a flow chemistry apparatus.