Enantioselective aza-Henry reaction of t-boc protected imines and nitroalkanes with bifunctional squaramide organocatalysts

Susam, Dilşad
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 quinine based novel bifunctional organocatalyst, which has been developed in our group, up to 91% ee under the optimized condition with 10 mol% catalyst loading. In the second part of the thesis, preliminary studies of enantioselective Henry, aldol, decarboxylative aldol and Friedel-Crafts type substitution domino reactions were conducted with bifunctional organocatalysts. Among these studies, the best result was achieved with Friedel-Crafts type substitution domino reaction as 92% ee in 10 minutes.


Enantioselective Michael addition of malononitrile to chalcone with bifunctional squaramide organocatalysts
Sargın, Nurdan; Tanyeli, Cihangir; Department of Chemistry (2015)
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 ...
Enantioselective aza-Henry reaction of t-Boc protected imines and nitroalkanes with bifunctional squaramide organocatalysts
Susam, Zeynep Dilşad; Tanyeli, Cihangir (2017-05-07)
An organocatalytic asymmetric aza-Henry reaction of t-Boc protected imines with nitroalkanes has been established by chiral acid-base type bifunctional Cinchona alkaloid/squaramide organocatalysts. The cooperation of a quinine motif as a base and sterically encumbered squaramide (H-bond donor) enabled mostly complete conversion of a range of reactants into the corresponding aza-Henry products at room temperature with good selectivities (up to 91% ee with 10 mol% catalyst loading).
Concise synthesis, electrochemistry and spectroelectrochemistry of phthalocyanines having triazole functionality
KARACA, Huseyin; SEZER, Serdar; Ozalp-Yaman, Seniz; Tanyeli, Cihangir (Elsevier BV, 2014-04-10)
The synthesis of novel metallophthalocyanines (M = Zn, Ni) bearing substituted benzyl protected 1,2,3-triazole moieties at peripheral positions is described for the first time via direct cyclotetramerization. These complexes have been characterized by a combination of FT-IR, H-1 NMR, HRMS and UVVis spectroscopy techniques and all the new compounds are highly soluble in most common organic solvents. In addition, the electrochemical and electrochromic behaviors of the complexes are investigated. Cyclic voltam...
Asymmetric diethylzinc addition to N-sulphonyl and N-phosphinoyl arylaldimines
Çağlı, Eda; Doğan, Özdemir; Department of Chemistry (2013)
Design of new chiral ligands for asymmetric synthesis is important. The ligand should be economical and efficient in enantioselective transformations. For the synthesis of some natural products and biologically active compounds, optically active amines are used as important intermediates. For this reason, it is significant to develop new catalyst system which can produce optically active amines in an economical and efficient way. Our group developed PFAM ligands and used successfully for the enantioselectiv...
Highly efficient and selective olefination of acyl phosphonates with ethyl diazoacetate catalyzed by a cobalt(II) porphyrin complex
Erturk, Erkan; Demir, Ayhan Sıtkı (Elsevier BV, 2008-08-04)
The cobalt(II) porphyrin complex (CoTPP) was found to be an efficient catalyst for the Wittig type olefination of acyl phosphonates with ethyl diazoacetate (EDA) in the presence of triphenylphosphine (Ph(3)P). By using this one pot methodology under mild conditions, densely functionalized vinyl phosphonates were obtained in high yields and high E/Z selectivities in relatively short reaction times. A rather broad substrate spectrum and steric influence on the reaction rate were observed.
Citation Formats
D. Susam, “Enantioselective aza-Henry reaction of t-boc protected imines and nitroalkanes with bifunctional squaramide organocatalysts,” M.S. - Master of Science, Middle East Technical University, 2015.