Stereoselective oxidation of sulfides to sulfoxides by n-chloramines

Download

index.pdf

Date

2014

Author

İpek, Halil

Metadata

Show full item record

Item Usage Stats

135
views

59
downloads

Chiral sulfoxides are present in many biologically active compounds. Asymmetric synthesis of the sulfoxides has been performed by chiral metal complexes and chiral peroxides. Although the asymmetric organooxidation of sulfides by chiral peroxides proved to be successful, peroxides are difficult to handle and obtain. In this study, a new metal free method has been developed to oxidize sulfides to chiral sulfoxides with easily accessible chiral N-chloramines. For this purpose, chiral reagents were synthesized and chlorinated to yield N-chloramines. In oxidation reactions, chiral information has been transferred to sulfides with the transfer of chlorine onto sulfur from nitrogen. With N-chloramines, we observed enantioenriched sulfoxide formation. The results were also subjected to computational studies. These studies revealed that the amine-Cl goes through anion pair intermediate while imide-Cl transfers chlorine in an SN2 fashion. The observed results have been promising, yet the conditions still need to be further optimized.

Subject Keywords

Sulfides., Sulfoxides., Oxidation., Chloramines., Asymmetry (Chemistry).

URI

http://etd.lib.metu.edu.tr/upload/12617964/index.pdf
https://hdl.handle.net/11511/24139

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

ENANTIOSELECTIVE OXIDATION OF THIOANISOLE TO METYL PHENYL SULFOXIDE BY CHIRAL COMPOUNDS BEARING N-Cl BOND İPEK, HALİL; Akdağ, Akın (Informa UK Limited, 2015-08-03) Chiral sulfoxides are used in asymmetric synthesis and are present in various biologically active compounds. Asymmetric synthesis of the sulfoxides has been performed by chiral metal complexes and non-metals containing peroxide and oxide moieties. In this study, a new metal free method has been developed to oxidize thioanisole into methyl phenyl sulfoxide with easily accessible chiral compounds carrying N-Cl bond. For this purpose, chiral amine and amide bearing reagents were synthesized and chlorinated by ...
Chemoenzymatic synthesis of 2-ethyl-5-hydroxy-3- methoxy-cyclopent-2-enone Dalfidan, Çağla; Demir, Ayhan Sıtkı; Department of Chemistry (2005) Chiral hydroxylated cyclopentane derivatives are important precursors for biologically active compounds. Synthesis of these types of compounds in optically pure form found increased interest in pharmaceutical chemistry. 2-ethyl-cyclopentane-1.3-dione was acetoxylated using manganese III acetate at preferred positions. Enzyme catalyzed enantioselective hydrolysis or enantioselective acetoxylation of hydrolyzed acetoxy derivatives gives the corresponding hydroxylated diketones in optically pure form.
Stereoselective synthesis of cyclopentanoids and cyclitol derivatives originated from polychlorinated norbornene systems Gümüş, Ayşegül; Tanyeli, Cihangir; Department of Chemistry (2009) Optically active polychlorinated norbornene systems are important starting compounds for the synthesis of many complex molecules. The synthetic strategy of this study mainly depends upon the enzymatic resolution of hydroxymethyl-substituted polychlorinated norbornene structures. The enantiomerically enriched acetoxymethyl derivatives were synthesized in high ee values by several lipases. The absolute configuration of tetrachlorinated norbornene system was determined by X-ray analysis. The second part of the...
Studies on the reaction of acyl phosphonates with aldehydes in the presence of proline Yalçınkaya, Hatice; Demir, Ayhan Sıtkı; Department of Chemistry (2009) Acyl phosphonates are interesting precursors for the synthesis of biologically active compounds. In the first part, the acyl phosphonates are synthesized starting from the corresponding acyl chloride. The acyl chlorides are converted into acyl phosphonates by using trialkylphosphites. The reaction of acyl phosphonates with aldehydes in the presence of proline furnished not the suggested aldol products via proline catalyzed aldol reaction but bicyclic products via one pot tricomponent 1,3-dipolar cycloadditi...
Oxidative ring opening reactions of a-hydroxy ketones Aybey, Ayşe; Demir, Ayhan Sıtkı; Department of Chemistry (2008) Chiral polyfunctionalized 1,5-dicarbonyl compounds are important synthetic intermediates and starting materials for many biologically active compounds so their synthesis has a great importance in the literature. In the first step, 1,3-cyclohexandione and other b-diketone derivatives are protected under acid catalyzation and their corresponding b-keto enol ether derivatives are obtained. These b-keto enol ethers are then converted to a-acetoxy enones in racemic form by Mn(OAc)3 mediated oxidation. Enzymatic ...

Citation Formats

H. İpek, “Stereoselective oxidation of sulfides to sulfoxides by n-chloramines,” M.S. - Master of Science, Middle East Technical University, 2014.