In this work, a series of α‐amino acids (L‐Phe, D‐Phe, L‐Trp) and several α,β‐dipeptides (H2N‐L‐Val‐N‐Bn‐β‐Ala‐COOH and H2N‐L‐Leu‐N‐Bn‐β‐Ala‐COOH) intercalated into hydrotalcite (Mg/Al, x=0.333) were prepared by high speed ball milling (HSBM) assisted rehydration/reconstruction methods, followed by sonication and mechanical stirring. All organic‐inorganic hybrid samples were characterized by powder X‐ray diffraction (XRD) and FTIR‐ATR spectroscopy. The catalytic activity of the resulting hydrotalcite‐supported materials (natural and hybrid) was evaluated in the asymmetric Michael addition reaction of α,α‐disubstituted‐aldehydes to N‐substituted‐maleimides. Pristine (HTS), calcined (HTC) and water‐reconstructed (HTR‐l) hydrotalcite‐derived materials exhibited very low catalytic activities, affording racemic mixtures of the anticipated Michael adduct. By contrast, hybrid materials showed better activities, especially HTR‐α‐amino acid catalysts afforded Michael products in up to 94 % yield and with rather high enantioselectivity (enantiomeric ratio (e.r.) up to 99 : 1) at room temperature under neat reaction conditions. The effect of solvents and Brønsted basic or acidic additives was evaluated using the best hybrid catalyst, HTR‐L‐Phe. In addition, recycling and reuse of the catalyst (up to 4 cycles) and large‐scale experiments was successfully carried out.

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Knowledge accumulated in the field of organocatalysis led to the design and synthesis of three novel and efficient organocatalysts for the stereoselective aldol and Michael reactions in the presence of water.

A highly diastereoselective and enantioselective Michael addition of enolizable ketones such as cyclohexanone and acetophenone to a variety of substituted trans‐β‐nitrostyrenes and chalcones was catalyzed by a novel chiral and unsymmetrical thiourea as organocatalyst in the presence of water or under neat reaction conditions. The anticipated Michael adducts, γ‐nitrocarbonyl adducts and 1,5‐dicarbonyl derivatives, were obtained in up to 98:2 diastereomeric ratio and up to 96 % enantiomeric excess. The application of this new chiral organocatalyst was extended to an asymmetric Michael addition‐proton transfer‐aldol reaction cascade process, a formal [3+3] cyclization reaction of cyclohexanone with arylidenepyruvates, with high stereoselectivity. The organocatalyst reported here is one of the very few able to promote the above cascade process, providing the important bicyclic framework that is found in many natural products.

Curcumin and its analogs, chalcones, and C5-monocarbonyl are molecules of great therapeutic potential, but their poor stability and hydrophobicity have hampered their extensive use in clinical trials. Therefore, significant efforts...