Physical Sciences and Mathematics Commons^™

Development Of Chiral Lewis Base Catalysts For Chlorosilane-Mediated Asymmetric C-C Bond Formations, Changgong Xu

Theses and Dissertations

The chiral hydrazine is a crucial structural motif that serves as pivotal structural elements in numerous natural products and biologically significant molecules. We are particularly interested in the catalytic asymmetric reduction of hydrazones, as well as the catalytic asymmetric propargylation and allenylation of hydrazones, because they provide direct pathways to these enantio-enriched chiral building blocks. In this work, we will explore the potential of two different categories of chiral Lewis base catalysts in the said transformations.

Developed by another student in our group, axial-chiral 3,3’-triazolyl biisoquinoline N,N’-dioxides derived catalysts are tested and demonstrated its capability in activating various hydrazone …

Synthesis And Mao Inhibitory Activity Of Novel Thiazole-Hydrazones, Özlem Atli, Yusuf Özkay

Turkish Journal of Chemistry

A series of new thiazole-hydrazones 3a-3n were synthesized, characterized, and screened for their $h$MAO-A and $h$MAO-B inhibitory activity by an in vitro fluorometric method. Selectivity indexes (SIs) were expressed as IC$_{50}$ (MAO-A) / IC$_{50}$ (MAO-B). Compound 3f showed promising $h$MAO-A inhibition with an IC$_{50}$ value of 1.20 $\mu $M and displayed a very significant SI of 0.04 towards $h$MAO-A. The mechanism of $h$MAO-A inhibition was investigated by enzyme kinetics using Lineweaver--Burk graphics. Compound 3f was further screened for its cytotoxicity by using a healthy NIH/3T3 mouse embryonic fibroblast cell line (ATCC CRL1658) and was evaluated as nontoxic at its effective …

Comparative Study Of Microwave-Assisted And Conventional Synthesis Of Ibuprofen-Based Acyl Hydrazone Derivatives, Ayşe Uzgören Baran

Turkish Journal of Chemistry

A series of potential biological active acyl hydrazone derivatives containing ibuprofen moiety (compounds 4a--4p) was synthesized by the condensation of ibuprofen hydrazone with aromatic aldehydes using conventional and microwave irradiation methods. The microwave method was found to be successful with nearly the same or higher yields and shorter reaction time, and it was more environmentally friendly compared to the conventional heating method. The chemical structures of the synthesized compounds were characterized by IR, ^1H NMR, and APT-NMR spectroscopy.

The Importance Of The Rotor In Hydrazone-Based Molecular Switches, Xin Su, Timo Lessing, Ivan Aprahamian

Dartmouth Scholarship

The pH-activated E/Z isomerization of a series of hydrazone-based systems having different functional groups as part of the rotor (R = COMe, CN, Me, H), was studied. The switching efficiency of these systems was compared to that of a hydrazone-based molecular switch (R = COOEt) whose E/Z isomerization is fully reversible. It was found that the nature of the R group is critical for efficient switching to occur; the R group should be a moderate H-bond acceptor in order to (i) provide enough driving force for the rotor to move upon protonation, and (ii) stabilize the obtained Z configuration, to …

Synthesis Of Novel Tetraoxime Derivative With Hydrazone Side Groups And Its Metal Complexes, İlknur Babahan, Hüseyi̇n Anil, Nursabah Sarikavakli

Turkish Journal of Chemistry

In this study, the synthesis of a novel tetraoxime (LH_4) derivative containing hydrazone side groups, and its transition metal complexes with Ni(II), Cu(II), Co(II), and Zn(II) ions, were reported. The ligand was synthesized by reacting anti-glyoximehydrazine (GH_2) with terephthaldialdehyde. Polymeric complexes with Ni(II) and Co(II) and binuclear complexes with Cu(II) and Zn(II) of this tetraoxime were isolated. Structural assignments were supported by a combination of ^1H-NMR, ^{13}C-NMR, HMQC, FT-IR, UV-Vis, thermogravimetric analysis (TGA), molar conductances, elemental analyses, and magnetic susceptibility.

Synthesis Of New Azo Dyes And Copper(Ii) Complexes Derived From Barbituric Acid And 4-Aminobenzoylhydrazone, Bülent Kirkan, Ramazan Gup

Turkish Journal of Chemistry

Four new azo dyes, L^1, L^2, L^3, and L^4, were prepared by linking benzaldehyde p-aminobenzoylhydrazone (3) and p-hydroxybenzaldehyede p--aminobenzoylhydrazone (4) to barbituric acid and 1,3-dimethylbarbituric acid through diazo-coupling reactions. Reactions of the azo-dyes with copper chloride and bidentate ligand, 1,10-phenanthroline, produced mixed-ligand dinuclear complexes with general stoichiometry [Cu_2L(phen)_2]Cl_2 (7, 8, 9, and 10). The structures of both azo dyes and their complexes were identified by elemental analyses, FT-IR, ^1H-NMR, UV-VIS, magnetic susceptibility, and mass spectral data.