Cu-catalyzed selective mono-n-heteroarylation of chiral diamines & asymmetric conjugate addition of dibenzoylmethane to trans-beta-nitrostyrene

Download
2013
Ünver, Muhammet Yağız
In the first part of the thesis, a new methodology has been developed to desymmetrize trans-(R,R)-cyclohexane-1,2-diamine, a C2-symmetrical most demanding chiral backbone, by using copper chemistry (modified Ullman). Various halo substituted nitrogen heteroaromatic compounds were selectively introduced to one of the diamine unit. 10 novel coupling products were synthesized in a single step procedure. These resultant coupling products have amidine motifs which can be valuable candidates as a basic catalophoric part in the context of bifunctional organocatalyst. The second part of the thesis comprises the asymmetric organocatalytic Michael addition of dibenzoylmethane to various β-nitroolefins. 2-AminoDMAP/Squaramide type bifunctional acid/base organocatalyst, developed in our research group, has been used under optimized condition with very low catalyst loading and short reaction duration. Enantioselectivities of 14 chiral Michael addition products are varied between 80-98% ee.

Suggestions

Stereoselective construction of 2-oxindole fused spirocycle precursors /
Karahan, Seda; Tanyeli, Cihangir; Department of Chemistry (2019)
Recent literature on the bioactivity of isatin (indoline-2,3-dione) derivatives triggered organic chemists to make use of the unique potential of isatin in asymmetric organocatalytic synthesis. Due to extensive presence of 2-oxindole skeleton, especially spiro-fused cycles, in many natural products, they drew the special interest in the disciplines of medicinal chemistry and agrochemistry. Due to highly reactive prochiral carbonyl group, isatins are potent precursors for the synthesis of 3,3-disubstituted s...
Catalytic reaction of propylene to propylene oxide on various catalysts
Kalyoncu, Şule; Önal, Işık; Şeker, Erol; Department of Chemical Engineering (2012)
Throughout this thesis work, various catalysts were investigated with combinational approach to develop highly active and selective novel catalysts for direct epoxidation of propylene to PO using molecular oxygen. The promoted and un-promoted silver (Ag), copper (Cu), ruthenium (Ru), manganese (Mn) mono and multimetallic catalytic systems over different silica supports were prepared via sol-gel method and incipient wetness method. In addition to support effect, the effects of different promoters on the cata...
Ni and cu incorporated mesoporous nanocomposite catalytic materials
Nalbant, Asli; Doğu, Timur; Balci, Suna (2008-02-01)
Nickel and copper incorporated MCM-41-like mesoporous nanocomposite materials prepared by the direct hydrothermal synthesis and the impregnation procedures showed highly attractive pore structure and surface area results for catalytic applications. The XRD patterns showed that characteristic MCM-41 structure was preserved for the materials synthesized following an impregnation procedure before the calcination step. The surface area of the Cu impregnated material with a quite high Cu/Si atomic ratio (0.19) w...
Structure sensitive hydrogen adsorption: Effect of Ag on Ru/SiO2 catalysts
Savargaonkar, N; Narayan, RL; Pruski, M; Üner, Deniz; King, TS (Elsevier BV, 1998-08-15)
The dynamics and energetics of hydrogen chemisorption on silica-supported ruthenium and ruthenium-silver bimetallic catalysts were studied by H-1 NMR spectroscopy and microcalorimetry. It was observed that the amount of hydrogen adsorbed on Ru particles having intermediate and low heats of adsorption was significantly reduced with increasing amounts of silver. The desorption and adsorption rate constants, determined from selective excitation NMR experiments, were lower on Ru-Ag catalysts than those on Ru ca...
Theoretical and experimental investigation of water-gas shift reaction over supported copper/iron oxide catalysts
Yalçın, Özgen; Önal, Işık; Department of Chemical Engineering (2017)
Density functional theory calculations were carried out to investigate the role of the chromium and copper, which were demonstrated to act as textural and catalytic promoters, respectively, for the Fe3O4-Cr2O3-CuO catalyst system by in situ experimental studies at the atomic scale. There is a minor effect of Cr on the dissociative adsorption of H2O, but no effect on CO adsorption on the Feoct2 termination of Fe3O4 (111) surface indicating that Cr does not act as a chemical promoter. Copper promotion of the ...
Citation Formats
M. Y. Ünver, “Cu-catalyzed selective mono-n-heteroarylation of chiral diamines & asymmetric conjugate addition of dibenzoylmethane to trans-beta-nitrostyrene,” M.S. - Master of Science, Middle East Technical University, 2013.