Additive and Emergent Catalytic Properties of Dimeric Unnatural Amino Acid Derivatives: Aldol and Conjugate Additions
| Autor: | Tamara Bello, Fernando P. Cossío, Abel de Cózar, Andrea Ruiz-Olalla, María de Gracia Retamosa, Maddalen Agirre |
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| Přispěvatelé: | Universidad de Alicante. Departamento de Química Orgánica, Universidad de Alicante. Instituto Universitario de Síntesis Orgánica |
| Rok vydání: | 2021 |
| Předmět: |
chemistry.chemical_classification
Aldehydes Stereochemistry Organic Chemistry Enantioselective synthesis asymmetric catalysis Stereoisomerism conjugate additions General Chemistry Ketones DFT calculations Catalysis Amino acid Química Orgánica Aldol reaction chemistry aldol reaction Amino Acids 1 3-dipolar reactions Conjugate |
| Zdroj: | Addi. Archivo Digital para la Docencia y la Investigación instname RUA. Repositorio Institucional de la Universidad de Alicante Universidad de Alicante (UA) |
| ISSN: | 1521-3765 0947-6539 |
| Popis: | [EN]Different densely substituted L- and D-proline esters were prepared by asymmetric (3+2) cycloaddition reactions catalyzed by conveniently selected EhuPhos chiral ligands. The gamma-nitro-2-alkoxycarbonyl pyrrolidines thus obtained in either their endo or exo forms were functionalized and coupled to yield the corresponding gamma-dipeptides. The catalytic properties of these latter dimers were examined using aldol and conjugate additions as case studies. When aldol reactions were analyzed, an additive behavior in terms of stereocontrol was observed on going from the monomers to the dimers. In contrast, in the case of the conjugate additions between ketones and nitroalkenes, the monomers did not catalyze this reaction, whereas the different gamma-dipeptides promoted the formation of the corresponding Michael adducts. Therefore, in this latter case emergent catalytic properties were observed for these novel gamma-dipeptides based on unnatural proline derivatives. Under certain conditions stoichiometric amounts of ketone, acid and nitroalkene), formation of N-acyloxy-2-oxooctahydro-1H-indoles was observed. Financial support for this work was provided by the Spanish Ministerio de Ciencia e Innovación (MICINN-FEDER, Grants PID2019-104772GB-100 and RED2018-102387-T) and the Gobierno Vasco/Eusko Jaurlaritza (GV/EJ, Grant IT-1346-19). A.R.-O. thanks the Ministerio de Ciencia, Innovación y Universidades for her Ph.D. grant. M.d.G.R thanks the DIPC and UPV/EHU for her postdoctoral contract. The authors thank Dr. José I. Miranda (SGIker-UPV/EHU) for his assistance with nuclear magnetic resonance spectroscopy. The authors also thank the SGI/IZO-SGIker of the UPV/EHU and the DIPC for generous allocations of analytical and computational resources. |
| Databáze: | OpenAIRE |
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