Enantioselective Michael addition of malononitrile to chalcone with bifunctional squaramide organocatalysts

Sargın, Nurdan
4H-pyran derivatives show diverse biological activity such as antimicrobial, antibacterial, antiviral and antifungal. 4H-pyran derivatives can be synthesized easily from 2-(3-oxo-1,3-diphenylpropyl)malononitrile which is the Michael addition product of malononitrile to trans-chalcone. Synthesizing chiral biologically active compounds with metal free approach (organocatalysis) is a significant topic. In this thesis, chiral 2-(3-oxo-1,3-diphenylpropyl)malononitrile was synthesized with quinine or 2-aminoDMAP based novel bifunctional organocatalysts which were developed in our group. In the asymmetric Michael addition reaction, 2-adamantyl anchored quinine-squaramide organocatalyst was found the best among the other tested organocatalysts in the optimization reactions. Consequently, 10 different derivatives of Michael product were synthesized up to 86% ee under the optimized condition with very low catalyst loading (0.5 mol%).


Enantioselective synthesis of new chiral 2-aziridinyl phosphonates and studies of their biological activities
Doğan, Özdemir; Beksultanova, Nurzhan; ALTANLAR, NURTEN; Simsek, Duygu; KARABIYIK, HASAN (2017-02-15)
A new series of chiral aziridinyl phosphonates has been synthesized and evaluated for antibacterial and antifungal activities. For the synthesis, a Gabriel-Cromwell reaction was used to form aziridinyl phosphonates in 52-83% yield. In order to evaluate antibacterial and antifungal activities, MIC values were measured. Although most of the compounds showed insignificant activity, two of them provided low to moderate antifungal activity.
Enantioselective aza-Henry reaction of t-boc protected imines and nitroalkanes with bifunctional squaramide organocatalysts
Susam, Dilşad; Tanyeli, Cihangir; Department of Chemistry (2015)
The first part of this thesis comprises the application of a Cinchona alkaloid derived, bifunctional squaramide organocatalyst in the aza-Henry reaction of t-Boc protected imines and nitroalkanes. The target chiral β-nitroamines are chosen because; they are quite feasible for the corresponding α-amino acids and 1,2-diamines, which are basic structural motif in many natural products and key materials of the many pharmaceuticals. In this part, 12 different chiral β-nitroamine derivatives were synthesized with...
Enzymatic extraction of activated sludge extracellular polymers and implications on bioflocculation
Sesay, Ml; Özcengiz, Gülay; Sanin, Faika Dilek (Elsevier BV, 2006-04-01)
This study examines enzyme hydrolysis, a mild, effective, but a rarely used method of extracellular polymer extraction, in removing polymers from mixed culture activated sludge flocs. Two carbohydrate specific enzymes (a-amylase and cellulase) and a protein specific enzyme (proteinase) are used during the study. First, the kinetic aspect is investigated, then enzyme dose optimization is carried out on laboratory grown activated sludge samples cultured at solids retention times (SRT) of 4 and 20 days. A more...
Enantioselective michael addition of 1-nitropropane to nitroolefins with 2-aminodmap and quinine based bifunctional organocatalysts
Kanberoğlu, Esra; Tanyeli, Cihangir; Department of Chemistry (2015)
1,3-dinitro compounds are key materials in the synthesis of a variety of important fine chemicals. Moreover, they are reduced to 1,3-diamines which are starting materials of biologically active compounds, agrochemicals and pharmaceuticals. In this study, ((2S,3S)-1,3-dinitropentan-2-yl)benzene was synthesized via the Michael addition of 1-nitropropane to trans-β-nitrostyrene in the presence of chiral bifunctional 2-aminoDMAP and quinine based organocatalysts. In the first part of study, reaction conditions ...
Enantioselective formal synthesis of pregabalin with bifunctional acid/base organocatalysts
Kapucu, Merve; Tanyeli, Cihangir; Department of Chemistry (2013)
Pregabalin, which is marketed under the brand name of Lyrica by Pfizer, is an important chiral drug in the treatment of epilepsy and neuropathic pain. Since only S-Pregabalin is active for the treatment, asymmetric synthesis was accomplished in 6 steps and the chiral induction was done by transition metal catalysis in industrial production. In this thesis, we applied an alternative synthetic route taken place in 3 steps. The key step comprised the chiral induction done by organocatalysis and the formal asym...
Citation Formats
N. Sargın, “Enantioselective Michael addition of malononitrile to chalcone with bifunctional squaramide organocatalysts,” M.S. - Master of Science, Middle East Technical University, 2015.