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Asymmetric Synthesis and Mechanistic Studies on Copper(I)-Catalyzed Substitution of Allylic SubstratesNorinder, Jakob January 2006 (has links)
<p>This thesis deals with the copper-catalyzed substitution of allylic substrates.</p><p>In the first part of this thesis, the synthesis of a series of metallocenethiolates is described. The thiolates were examined as ligands in the enantioselective copper(I)-catalyzed γ-substitution of allylic acetates.</p><p>The second part describes a study on copper-catalyzed α-substitution of enantiomerically pure secondary allylic esters. It was observed that the degree of chirality transfer is strongly dependent on the reaction temperature. The loss of chiral information is consistent with an equilibration of the allylCu(III) intermediates prior to product formation, which is essential in order to realize a copper-catalyzed dynamic kinetic asymmetric transformation process.</p><p>The third part describes a study on copper-catalyzed stereoselective α-substitution of enantiopure acyclic allylic esters. This method, when combined, with ruthenium and enzyme catalyzed dynamic kinetic resolution of allylic alcohols, provides a straightforward route to pharmaceutically important α-methyl carboxylic acids.</p><p>The fourth part is a mechanistic study on the reaction of perfluoroallyl iodide with organocuprates. Experimental studies as well as theoretical calculations were used to explain the contrasting reactivity of perfluoroallyl iodide vs. allyl iodide in cuprate allylation reactions.</p><p>In the fifth part, the development of a practical and useful method for the preparation of pentasubstituted acylferrocenes is presented.</p>
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Synthesis and Photochemical Properties of Poly(phenylenevinylene)s with Highly Regulated Structures / 高度に構造制御されたポリ(フェニレンビニレン)の合成および光化学的性質 / コウド ニ コウゾウ セイギョサレタ ポリ ( フェニレンビニレン ) ノ ゴウセイ オヨビ コウカガクテキ セイシツWakioka, Masayuki 24 September 2009 (has links)
Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第14942号 / 工博第3169号 / 新制||工||1475(附属図書館) / 27380 / UT51-2009-M856 / 京都大学大学院工学研究科物質エネルギー化学専攻 / (主査)教授 小澤 文幸, 教授 大江 浩一, 教授 中村 正治 / 学位規則第4条第1項該当
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Asymmetric Synthesis and Mechanistic Studies on Copper(I)-Catalyzed Substitution of Allylic SubstratesNorinder, Jakob January 2006 (has links)
This thesis deals with the copper-catalyzed substitution of allylic substrates. In the first part of this thesis, the synthesis of a series of metallocenethiolates is described. The thiolates were examined as ligands in the enantioselective copper(I)-catalyzed γ-substitution of allylic acetates. The second part describes a study on copper-catalyzed α-substitution of enantiomerically pure secondary allylic esters. It was observed that the degree of chirality transfer is strongly dependent on the reaction temperature. The loss of chiral information is consistent with an equilibration of the allylCu(III) intermediates prior to product formation, which is essential in order to realize a copper-catalyzed dynamic kinetic asymmetric transformation process. The third part describes a study on copper-catalyzed stereoselective α-substitution of enantiopure acyclic allylic esters. This method, when combined, with ruthenium and enzyme catalyzed dynamic kinetic resolution of allylic alcohols, provides a straightforward route to pharmaceutically important α-methyl carboxylic acids. The fourth part is a mechanistic study on the reaction of perfluoroallyl iodide with organocuprates. Experimental studies as well as theoretical calculations were used to explain the contrasting reactivity of perfluoroallyl iodide vs. allyl iodide in cuprate allylation reactions. In the fifth part, the development of a practical and useful method for the preparation of pentasubstituted acylferrocenes is presented.
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Carbon-Carbon Bond Forming Reactions of Metal-Bonded Hydrocarbon Groups on Ag(111): Steric, Electronic, and Carbon Hybridization Effects on the Coupling RatesLee, Long-chen 06 August 2006 (has links)
The alkyl substitution effects and the hybridization effects on the rate of coupling of adsorbed hydrocarbon groups on Ag(111) have been investigated under ultrahigh vacuum by temperature programmed reaction/desorption (TPR/D). For these two different issues, two types of halide precursors were used. One is to form adsorbed fragments bearing C£\(sp3) and C£\-H, the other is to yield adsorbed fragments with different hybridized £\-carbons without C£\-H. The desired hydrocarbon groups were generated on Ag(111) by the thermal dissociation of the C-X (X = I or Br) bond in the corresponding halogenated compounds. Substitution of alkyl for hydrogen in the adsorbed alkyl groups systematically raises the coupling temperature. For example, 3-pentyl groups homo-couple at temperatures ~ 70 K higher than the ethyl homo-coupling reaction. The concept of ¡§geminal repulsion¡¨ can account for our experimental results while the size and the number of the alkyl substitution groups increase. Different hybridized C£\ (metal-bonded carbon) species cause various angle strain energies in the cyclic transition state for the coupling reaction. The C£\(sp) species (CH3C¡ÝC(ad) and (CH3)3SiC¡ÝC(ad)) have rather high coupling temperatures (~ 460 K) due to the unidirectional sp orbital and the stronger Ag-C(sp) bond in the transition state. The relative rates for homo-coupling as a function of the hybridization of the metal-bound carbon follow the trend sp3 > sp2 > sp on the Ag(111) surface. Lastly, we found that the isobutyl groups undergo a £]-hydride elimination instead of homo-coupling on the Ag(111) surface. It may be due to that isobutyl groups have a total of nine £]-hydogens among all the hydrocarbon groups, which makes this rare reaction pathway possibly occur on Ag(111).
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