Short Synthesis of Novel Recyclable Chiral Bifunctional Thioureas from Aminoalkyl Polystyrene and their use as Organocatalysts in Stereoselective aza-Henry Reaction.

A series of supported bifunctional thioureas has been prepared, in one or two steps, from commercially available aminoalkyl polystyrene resins. They differ in the length of the tether attaching the thiourea to the polymer chain, and the nature of the amino thiourea component. All the materials are able to promote stereoselective aza-Henry reaction with very good stereoselection, and they can be recycled maintaining the catalytic activity.