Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
Browse
6 results
Search Results
Master Thesis The Synthesis of Furanones Via Rhodium-Catalyzed Carbonylative Addition Reactions of Arylboronic Acids To Alkynes(Izmir Institute of Technology, 2008) Dege, Fatma Nurcan; Artok, Levent; Artok, Levent; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of TechnologyThis study reveals that 5-Aryl-2(5H)-furanones can be synthesized by rhodiumcatalyzed reaction of arylboronic acids with internal alkynes under a CO atmosphere.In this thesis, relatively mild and simple method for synthesis of 2(5H)-furanones was developed. Our method was found to be applicable for various arylboronic acids and alkynes.The methodology of this study is well applicable for ortho-, para- and metasubstituted phenylboronic acids. But slightly higher yields were obtained with parasubstituted phenylboronic acids than ortho- or meta- substituted ones.It was found that when an asymmetric alkyne is used under the optimized conditions, aroylation occurs more on the electron deficient acetylenic carbon as compared with electron rich acetylene when aroylrhodium(I) species undergoes 1,2-addition to the carbon-carbon triple bond in the reaction. That affects the ratio of isomeric yields of furanones which were produced in the reactions of asymmetric alkynes with phenylboronic acid.2(5H)-Furanones that we synthesized can be used in many areas such as food manufacturing, perfume and medicinal industries.Master Thesis Rhodium-Catalyzed Reactions of (z)-2 Acetates With Arylboronic Acids(Izmir Institute of Technology, 2011) Karakuş, Erman; Artok, Levent; Artok, Levent; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of TechnologyThis study is the first example of rhodium(I)-catalyzed arylative SN2ʺ type reaction of (Z)-2-en-4-yne acetates with arylboronic acids leading to E-configured vinyl-allenes with an aryl moiety. The coordinative interaction of the rhodium with carbonyl oxygen promoted the -elimination of Rh(I)-OAc from the alkenylrhodium intermediate in both syn- and anti-modes, with the syn-elimination being the major path. DFT calculations revealed that a conformer of this intermediate which can lead to the E-configured vinylallene product via the syn-elimination mode, is energetically the most favorable conformer. The rhodium-catalyzed procedure is not applicable to reactions involving (E)- configured enyne acetates, because the geometry of the alkenylrhodium intermediate that is derived from the corresponding E-enyne acetate would not allow such coordinative interaction to occur.Master Thesis Synthesis of Α,β-Unsaturated Ketones by Rhodium-Catalyzed Carbonylative Arylation of Internal Alkynes With Arylboronic Acids(Izmir Institute of Technology, 2009) Kuş, Melih; Artok, Levent; Kuş, Melih; Artok, Levent; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technologyα,β-Unsaturated ketones are important key reagents in organic synthesis. They are commonly synthesised through an aldol condensation reaction.Since Hayashi et al. reported the first Rh-catalyzed addition of aryl- and alkenylboronic acids to α,β-unsaturated ketones, the Rh-catalyzed addition of organoboron reagents to various unsaturated systems has become increasingly popular as a method of constructing C.C bonds. Organoboron reagents readily undergo transmetalation with Rh to form arylrhodium(I) species that are capable of inducing the nucleophilic arylation of various electrophilic sites (Sakai, et al. 1997, Hayashi and Yamasaki 2003). In this work, we have succesfully performed another example of the Rhcatalyzed reaction of arylboronic acids: a reaction of arylboronic acids with alkynes under a CO atmosphere to yield α,β-unsaturated ketones (Kuş, et al. 2008). As a consequence, the methodology established in this study proposes arelatively mild and simple way for the synthesis of α,β-unsaturated ketones.Master Thesis The Syntheses of Indanones and Indenones Via Rhodium Catalyzed Carbonylative Arylation of Alkynes(Izmir Institute of Technology, 2009) Özkılınç, Fatma Yelda; Artok, Levent; Artok, Levent; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of TechnologyIndanones and indenones are important classes of compounds in organic chemistry. These structural motifs are found in various types of natural compounds and also can be used as intermediates in the synthesis of a variety of molecules.In this study, indanones and indenones were synthesized via rhodium catalyzed reaction of alkynes with arylboroxines under a CO atmosphere. Reactions were performed using para- and meta- substituted phenylboroxines. Higher yields were obtained for indanones with methyl- substitution on para- and meta-positions of phenylboroxines than methoxy-substituted ones. However, by using phenylboroxine with an electron withdrawing group, a lower yield of indanone was observed. Higher yields of indanone were obtained with electron poor diaryl acetylenes than electron rich ones.As a general result, the yields of indanone were higher than the yields of indenones at the end of the reaction. The desired products were purified with silica gel column chromatography and the structure of indanones and indenones were determined using GC, GC-MS, NMR, FT-IR and HRMS techniques.Master Thesis Rhodium-Catalysed Alkoxycarbonylative Cyclisation Reactions of 1,6-Enynes(Izmir Institute of Technology, 2010) Ziyanak, Fırat; Artok, Levent; Ziyanak, Fırat; Artok, Levent; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of TechnologyTransition metal-catalyzed carbonylation reactions of unsaturated systems that contain alkynyl moiety became usually used methodology for the synthesis of biologically active .,. unsaturated carbonyl compounds (Mise et. al., 1983, Yoneda et. al., 1999, Artok et. al., 2009). One type of these reactions is the alkoxycarbonylation reaction of unsaturated systems for the C-C bond formation with transition metals in the presence of alcohol and CO (Scrivanti et. al., 1998). In literature beside alkynes enyne molecules that contain more than one unsaturated moiety could also undergo transition metal-catalyzed carbonylation reactions (Rivero et. al., 2003, Shibata, 2006). Pauson-Khand reactions are well known and used reactions in literature for enyne molecules These type of reactions are transition metal-catalyzed carbonylative cyclization reactions of enyne molecules. However in literature there is no such an example for the alkoxycarbonylative reactions of 1,6-enynes. In this study rhodium-catalyzed alkoxycarbonylative cyclization reactions of 1,6 enyne molecules in the presence of alcohol and CO was performed.Master Thesis Rhodium Catalyzed Arylative Cyclization of Diynes With Arylboronic Acids(Izmir Institute of Technology, 2009) Ürer, Bağdagül; Artok, Levent; Artok, Levent; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of TechnologyThis study reveals that exo-conjugated cyclic dienes can be synthesized by rhodium(I) catalyzed arylative cyclization of unsymmetric diyne molecules with arylboronic acids. Cyclic dienes are important reagents in organic chemistry because they easily undergo [4+2] cycloaddition reactions with dienophiles and also, they are useful intermediates in the synthesis of complex polycyclic compounds. To form carbon.carbon bonds, transition metal catalyzed arylative cyclization reactions of unsaturated reagents with arylboronic acids is a useful and efficient way in organic synthesis. For this purpose, rhodium catalyzed arylative cyclization of enyne type unsaturated reagents have been found significantly in literature. In this study, unsymmetric diyne type molecules were reacted with arylboronic acids in the presence of a rhodium complex under argon atmosphere. The reactions proceeded effectively in methanol as a solvent under very mild reaction conditions.