• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • 1
  • 1
  • Tagged with
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Synthesis of 3,3¡¦-dihydroxy-2,2¡¦-bipyridine Derivatives and Applications

Tsai, Mi-Ting 15 August 2012 (has links)
The thesis can be divided into two chapters: synthesis and application. The first chapter presents the basis of synthesis. Generally, electronic-deficient aromatic molecules require activation before reacting with metal reagents and then can go coupling reaction. Our lab has developed a new bipyridine coupling method without pre-functionalization of pyridines to the corresponding activated halide or metal forms or using of transition metal catalysts. This new method is quite efficient and advantageous for environmental protection. In second chapter, we synthesized 3,3¡¦-dihydroxy-2,2¡¦-bipyridine -based molecules and the functional groups were modified to investigate its liquid crystal properties. According to analyzing data of differential scanning calorimetry (DSC), polarized optical microscope (POM) and powder x-ray diffraction (XRD), we found that a-3 may possess cubic mesophaes with Im3m symmetry, and a series of d-1~d-3 compounds exhibit mesophase and may be further identified as smectic phase.
2

ラジカル超原子価ヨウ素(III)試薬を用いた直接的C-H活性化反応の開発

臼井, 明日香 23 March 2015 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第18808号 / 理博第4066号 / 新制||理||1585(附属図書館) / 31759 / 京都大学大学院理学研究科化学専攻 / (主査)教授 丸岡 啓二, 教授 時任 宣博, 教授 大須賀 篤弘 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM
3

Development of new methods for the asymmetric formation of C-N bonds / Développement de nouvelles méthodes de formation asymétriques de la liaison C-N

Lishchynskyi, Anton 16 July 2012 (has links)
Au cours de ce travail de nouvelles méthodes pour la formation de liaison C-N ont été développées. Dans la première partie de cette thèse une application de catalyse métal-ligand bifonctionnelle pour la réaction énantiosélective aza-Michael est démontrée. Dans la deuxième partie nous présentons le travail sur les cyclisations, en utilisant des alcaloïdes du quinquina facilement disponibles, comme catalyseurs des plus prometteurs, fournissant des β-amino-acides d’indoline avec jusqu'à 98% ee. Parmi eux, l’hydroquinidine ressort du lot comme étant le catalyseur donnant le meilleur excès énatiomérique. La troisième partie est liée à l'élaboration d'un nouveau processus intermoléculaires de diamination de styrènes, diènes et triènes, utilisant des bis-sulfonylimides comme source d'azote, en combinaison avec le diacétate de iodosobenzène, qui fournit une approche intéressante et efficace de diamines vicinales biologiquement et chimiquement important. La réaction peut être effectuée à température ambiante sans avoir besoin de protection par atmosphère inerte. / The concept of metal-ligand bifunctionality was successfully applied for an enantioselective aza-Michael reaction by employing well-defined ruthenium amido complexes. The catalyst was optimised and the corresponding chiral indoline β-amino acid derivatives were obtained with high enantioselectivities. Next, a straightforward enantioselective bifunctional organocatalytic approach was also developed. Employing hydroquinidine as catalyst the corresponding cyclic products were obtained in excellent enantioselectivities and quantitative yields. These compounds can be selectively deprotected and applied to peptide synthesis. Finally, we have developed unprecedented diamination reactions of styrenes, butadienes and hexatrienes employing easily accessible hypervalent iodine(III) reagents under robust reaction conditions. The first examples of the metal-free 1,2-diamination of butadienes were demonstrated and this oxidation methodology was further extended to the highly attractive 1,4 installation of two nitrogen atoms within a single step.

Page generated in 0.0712 seconds