Novel studies on the chemoenzymatic synthesis of polychlorinated bicyclic systems and the synthesis of C2 and C3 symmetric chiral ligands

Türkmen, Yunus Emre
Optically active polychlorinated bicyclic systems are important starting materials for the synthesis of complex target molecules. In the first part of the study, the syntheses of several racemic and meso hexachloronorbornene derivatives were executed successfully, starting from hexachlorocyclopentadiene. The enantio-enriched acetoxymethyl derivative (-)-2 and the hemiester (-)-6 were synthesized in high e.e. values by using several hydrolase type enzymes. The absolute configuration of (-)-2 was determined by transforming it to the corresponding norbornene derivative (-)-7 with known absolute configuration. In the second part of the study, C2 symmetric chiral ligand (-)-11 and C3 symmetric chiral triamide derivative (-)-12 were synthesized in high chemical yields starting from L-proline. In connection to these studies, the syntheses of the monoamide derivative (-)-14 and the C2 symmetric diamide derivative (-)-15 were achieved by using appropriate amounts of L-proline.


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...
Synthesis of various camphor-based chiral pyridine derivatives
Işık, Murat; Tanyeli, Cihangir; Department of Chemistry (2005)
Chiral aromatic nitrogen heterocycles are finding many applications in asymmetric organic synthesis, particularly as ligands in the preparation of chiral metal complexes. Since camphor-based chiral auxiliaries are known to be especially effective, a number of pyridines fused to the camphor skeleton have been reported. It is well known that nicotinic acid and its derivatives exhibiting qualitatively the biological activity of nicotinamide, which acts as an electron acceptor in many biological redox reactions...
Asymmetric synthesis of norbornene based 1,4-Aminoalcohol derivatives and applications in asymmetric diethylzinc reactions
Erdem, Mine; Tanyeli, Cihangir; Department of Chemistry (2007)
The asymmetric synthesis of chiral norbornene based 1,4-aminoalcohols and their applications in asymmetric diethylzinc addition reactions was perfomed starting from meso-anhydride 50. The desymmetrization of this meso-anhydride 50 was done by the usage of quinine or quinidine cinchona alkaloids with very high enantiomeric excess values (up to 98% ee) and chemical yields. The Quinidine-mediated desymmetrization of meso-anhydride 50 with methanol gave (2R,3S)-(+)-cis-monoester 51. The amination of this result...
Asymmetric synthesis of N-aryl substituted chiral 1,4-aminoalcohol derivatives and applications in various asymmetric transformation reactions
Odabaş, Serhat; Tanyeli, Cihangir; Department of Chemistry (2007)
The asymmetric synthesis of N-aryl substituted chiral 1,4-aminoalcohols and their applications in asymmetric borane reduction and enantioselective diethylzinc addition to benzaldehyde reactions were performed starting from meso-anhydride 51 that is the cycloadduct of cyclopentadiene and maleic anhydride. The desymmetrization of meso-anhydride 51 was achieved by using quinine or quinidine with very high enantiomeric excess value (up to 98% ee) and with high chemical yield. The quinine-mediated desymmetrizati...
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...
Citation Formats
Y. E. Türkmen, “Novel studies on the chemoenzymatic synthesis of polychlorinated bicyclic systems and the synthesis of C2 and C3 symmetric chiral ligands,” M.S. - Master of Science, Middle East Technical University, 2006.