eng URI http://hdl.handle.net/10795/3004 ένζυμο υδρογόνο Enzymes are the foundation upon which the majority of organocatalysts bearing more than one catalytic functionalities and act either by covalent or non-covalent interactions, has been developed. The proline and its derivatives containing bio-isosteric groups as replacements of the carboxylic group, constitute a good example of catalysts that bring out transformations as the aldol and Michael reaction succesfully, via bifunctional catalysis.1 Important improvement has been the development of catalysts combining a proline or proline derivative unit with additional functionalities able to act as hydrogen bond donors. Amide catalysts based on (S)-proline and (1S,2S)-1,2-diphenylethylenediamine or (1S,2S)-1,2-diphenyl-2-aminoethanol are representative examples featuring amine or hydroxyl group respectively, as the terminal donor group.2 These analogues provide the opportunity of introducing chiral substituents between donor groups and/or to the terminal heteroatom, thus enhancing the efficacy of the resulting catalyst. Furthemore, combination of additional chiral units, together with even more hydrogen bond donors, would mimic much better a “miniature active site”, providing therefore multifunctional organocatalysts. We have shown that prolinamide catalyst based on (1S,2S)- 1,2 diphenylethylenediamine and bears a double hydrogen bond donor thiourea group linked to a substituted aromatic ring, efficiently catalyze the aldol reaction between ketones and aromatic aldehydes in high to quantitative yields and with high stereoselectivities.3 Herein, we report a structure activity relationship study undertaken to identify the functional groups of the catalyst responsible for the activity resembling structure activity relationship studies to identify the pharmacophores of a lead bioactive compound. A tripeptide-like prolinamide-thiourea catalyst having as building blocks (S)-proline (1S,2S)-1,2-diphenylenediamine and (S)-di-tertbutyl aspartate provides the products of the aldol reaction in high to quantitative yields and in high stereoselectivities (up to 99:1 dr and 99% ee). 3 pp. LOMv1.0 creator LOMv1.0 Scientific Coordinator LOMv1.0 Project Executing Organisation 2012-05-27 Digital Library of the Operational Programme "Education and Lifelong Learning" abstract types Text Enzymes Tripeptide-Like prolinamide Aldol Diphenylethylenediamine Hydrogen bond 845332 application/pdf http://repository.edulll.gr/edulll/bitstream/10795/3004/2/3004_1.72_%ce%91%ce%9d_25_5_12.pdf URI http://hdl.handle.net/10795/3004 LOMv1.0creator 2016-05-04T13:38:32Z LOMv1.0validator 2016-05-04T13:38:32Z LOMv1.0 gre no no Copyright EYD-EPEDBM (Operational Programme "Education and Lifelong Learning")