Master Degree / Yüksek Lisans Tezleri

Permanent URI for this collectionhttps://hdl.handle.net/11147/3008

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2008 - 20104

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Author: search.filters.author.Artok, LeventSubject: search.filters.subject.Alkynes

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Now showing 1 - 4 of 4
  • 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
    This 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
    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
    α,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
    Indanones 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
    Transition 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.