Novel styryl-substituted thioureas and squaramides were obtained in three steps from commercially available 4-hydroxy-3,5-dichloroaniline. These organocatalysts promote cascade reactions in high yields and excellent stereoselection. By using only 5 mol% loading of catalyst it is possible to obtain 2,3,4-trisubtituted benzopyrans by reaction of α-amidosulfones derived from salicyladehydes and nitrostyrenes, or 2,3,4-trisubstituted 4H-chromenes by reaction of the same α-amidosulfones with phenylsulfonylacetonitrile in excellent diastereo- and enantioselectivities. Two polymeric thiourea and squaramide were prepared by copolymerization of the best monomeric catalysts with styrene and divinylbenzene and used for the same transformations. These polymers behave also as excellent stereoselective catalysts that can be recovered and reused for five cycles.

Novel supported chiral bifunctional squaramides have been easily prepared starting from diamines derived from natural amino acids and commercially available aminoalkyl polystyrene resins. These squaramides behave as excellent stereoselective recoverable organocatalysts in different Michael additions, in neat conditions at room temperature. The reaction on 2-(2-nitrovinyl) phenol as electrophile lead, in excellent yields and enantioselectivities, to intermediates that can be easily transformed into 4H-chromenes, and spirochromanones.

Eight different biodegradable chitosan‐supported bifunctional chiral thioureas have been prepared as a greener and more sustainable alternative to those supported on petrochemical‐derived polymers. These organocatalysts promoted an enantioselective aza‐Henry reaction, which afforded good product yields with moderate to high enantioselectivity. The activity and stereodirecting ability of these materials were dependent on the accessibility of the reactants to the active site and increased with the length of the tether that connected the thiourea to the biopolymer. The best performing catalyst was able to be recovered and recycled five times without a loss of activity.