Fam-zinc catalyzed asymmetric 1,3-dipolar cycloaddition reactions of azomethine ylides and

Koyuncu, Hasan
In the first part of this study, four new chiral ligands (FAM) were synthesized and used in catalytic amounts in asymmetric 1,3-dipolar cycloaddition reactions of azomethine ylides. This method leads to the synthesis of chiral pyrrolidines, which are found in the structure of many biologically active natural compounds and drugs. It was found that using 10 mol% of one of these chiral ligands with different dipolarophiles (dimethyl maleate, dimethyl fumarate, methyl acrylate, tert-butyl acrylate, and Nmethylmaleimide), pyrrolidine derivatives could be synthesized in up to 94% yield and 95% ee. In the second part of the study, the catalytic activity of these chiral ligands were tested with titanium in asymmetric alkynylzinc addition reactions to aldehydes. By this method, chiral propargylic alcohols, which are important precursors for the natural products and pharmaceuticals can be synthesized. Using our catalyst, chiral propargylic alcohols were obtained in up to 96% yield and 98% ee. Although, most of the catalyst systems in the literature worked only with aromatic or aliphatic aldehydes and phenylacetylene, the catalyst system developed in this study worked with four different types of aldehydes (aromatic, aliphatic, heteroaromatic and a,b-unsaturated) and two different aliphatic acetylenes very successfully. Additionally, chiral ligand can be recovered in more than 90% yield and reused without losing its activity.


Tanyeli, Cihangir (Informa UK Limited, 1989-01-01)
Some phenolic biphenyl compounds have been synthesised via the annulation reactions of 4-methoxy-2- pyrone with various active methyl compounds.
Fam-Ti catalyzed enantioselective alkynylation of aldehydes
KOYUNCU, Hasan; Doğan, Özdemir (American Chemical Society (ACS), 2007-08-16)
Ferrocenyl-substituted aziridinylmethanol (Fam-1) has been used as a chiral catalyst with titanium for enantioselective alkynylation of aromatic, heteroaromatic, aliphatic, and alpha,beta-unsaturated aldehydes to give the corresponding propargylic alcohols in up to 96% yield and 96% ee. The ligand can be prepared easily and recycled.
Naphthazarin-Polycyclic Conjugated Hydrocarbons and Iptycenes
Dengiz, Çağatay; GUTIERREZ, Gregory D.; SWAGER, Timothy M. (American Chemical Society (ACS), 2017-07-21)
The synthesis of a set of naphthazarin-containing polycyclic conjugated hydrocarbons is described herein. Sequential Diels-Alder reactions on a tautomerized naphthazarin core were employed to access the final conjugated systems. Complete conjugation across the backbone can be achieved through complexation with BF2, as observed by (HNMR)-H-1 analysis and UV/vis spectroscopy. Precise synthetic control over the degree of oxidation of naphthazarin quinone Diels-Alder adduct 10 is additionally demonstrated and e...
DFT calculations of pentalenoquinones: towards the interception of 2-bromopentalene-1,5-dione
Atalar, Taner; Algi, Fatih; Balcı, Metin (ARKAT USA, Inc., 2008-01-01)
To reveal the stability and the aromatic character of pentalenoquinones (PQs) 1-4 and the corresponding bromo derivatives (Br-PQs) 6-9, DFT calculations (B3LYP/6-311+G(d,p)) concerning the geometry optimization, total energy and nucleus independent chemical shift (NICS) values were performed. It was found that all of the compounds have planar geometry. As the energy difference between HOMO-LUMO energy levels (Delta epsilon=epsilon(LUMO) - epsilon(HOMO)) and total energies were considered for the pentalene f...
Chemoenzymatic synthesis of chiral hydroxymethyl cycloalkenols
Şenocak, Deniz; Demir, Ayhan Sıtkı; Department of Chemistry (2004)
Chiral cyclic alkenols with hydroxymethyl functionality are important structural units in many biologically active natural compouds such as prostaglandins, sesquiterpene antiviral agents, pentenomycins, xanthocidin, sarkomycin, etc. 1,3-cycloalkanediones are converted into bicyclic polyoxo derivatives with formaldehyde and trioxane in the presence of Lewis acid. Selective oxidation of the bicyclic compounds by using manganese(III)acetate followed by enzyme-catalyzed kinetic resolution afforded chiral bicycl...
Citation Formats
H. Koyuncu, “Fam-zinc catalyzed asymmetric 1,3-dipolar cycloaddition reactions of azomethine ylides and,” Ph.D. - Doctoral Program, Middle East Technical University, 2007.