The accomplishment of the γ-alkylation reaction from β-keto esters of tropinone and the enantioselective aziridine formation from nortropinone is first reported. This opened two new paths to develop tropinone enolate chemistry. One is indirect α-alkylation of tropinone, another is the nucleophilic attack from α-C enolate to the nitrogen atom.<p>Seven interesting chiral amines have been synthesized and applied into the enolate chemistry of two interesting precursors of synthesis of natural products: 1,4- cyclohexanedione monoethylene ketal and tropinone.<p>The aldol reaction between the lithium enolate of 1,4-cyclohexanedione monoethylene ketal and benzaldehyde demonstrated the high diastereoselectivity (up to 98% de) and the moderate to high enantioselectivity (up to 75% ee) induced by those chiral lithium amides. On the other hand, high diastereoselectivity (up to 100% de) and the low enantioselectivity were obtained from the aldol reaction of tropinone enolate with benzaldehyde differentiated by chiral lithium amides with extra electron donor atoms.<p>An analysis method to determine enantioselectivity from racemic α-hydroxytropinone was developed. That will, no doubt, benefit the further enantioselective α-hydroxylation reaction of tropinone.

none

The reactions of organomagnesium akoxides EtMgOR (R= Me, Et) with dialkynyl magnesium complexes Mg(CoCR¢F) (R¢F= tBu, SiMe3) give a series of the tetranuclear magnesium complexes [Mg4(OR)2Et2(CoCR¢F)4(THF)4] (R= Me, Et; R¢F= tBu, SiMe3). The reactions of diethyl magnesium complexes MgEt2 with alkynes HCoCR (R= tBu, SiMe3) give two different kinds magnesium complexes. One kind is [Mg4(OEt)2-Et2(CoCR)4(THF)4] (R= tBu, SiMe3); another kind is [Mg4O(CoCR)6(THF)4] (R= tBu, SiMe3). Besides, the reaction of diisopropylamide magnesium complex Mg(NiPr2)2 with alkyne HCoCtBu give first example including two different kind bridge ligands trinuclear magnesium complex Mg3(NiPr2)2(CoCtBu)4(THF)2.

Stuttgart, Univ., Diss., 1999.

N-Acylethanolamines (NAEs) are a class of bioactive lipids, and FAAH is one of the enzymes responsible for degrading NAEs in both plants and animals. in plants, FAAH appears to be closely associated with ABA, a phytohormone which has long been associated with plant stress responses, since the overexpression of FAAH in Arabidopsis results in ABA hypersensitivity. Therefore, it is reasonable to speculate that alterations in FAAH transcript levels will result in altered stress responses in plants. to investigate this hypothesis experiments were carried out in which wild type (WT), FAAH-overexpressing (OE), and T-DNA insertional FAAH knockouts of Arabidopsis (faah) were grown in MS media under stress conditions. the stress conditions tested included chilling stress, heavy metal stress induced by cadmium or copper, nutrient limitations induced by low phosphorus or low nitrogen, salt stress induced with NaCl, and osmotic stress induced with mannitol. the OE plants were consistently hypersensitive to all stress conditions in relation to wild type plants. Inactive FAAH overexpressors did not have the hypersensitivity to the salt and osmotic stress of the active OE plants and were instead tolerant to these stresses. FAAH2 (faah2) knockouts and FAAH 1 and 2 double knockouts (faah 1+2) were based on some root development parameters somewhat more tolerant than WT plants, but more sensitive in terms of shoot growth. Collectively the data suggests that FAAH activity may interact with stress-responsive pathways in plants, perhaps including pathways involving ABA.

Au cours des dernières décennies, la chimie a pris une part croissante dans notre société et dans notre quotidien. Cette omniprésence a guidé les scientifiques des quatre coins de la planète à sans cesse étudier et développer de nouvelles technologies plus efficaces et moins coûteuses en ressources et en temps afin de répondre aux besoins toujours croissant imposés par notre société. Parmi les diverses branches couvertes par la chimie, la chimie organique joue un rôle prépondérant du fait de sa présence dans de nombreux domaines industriels tels que la chimie pharmaceutique, l’agrochimie, la science des matériaux ou encore la chimie des polymères. Cette nécessité toujours croissante de molécules organiques encourage par conséquent les chimistes organiciens à développer de nouveaux procédés surpassant les limitations rencontrées avec les méthodes usuelles ou donnant accès à de nouveaux types de composés impossible à synthétiser auparavant.L’un des exemples les plus frappants est sans conteste l’avènement de la chimie du fluor en synthèse organique. En effet, l’utilisation de cet atome par les chimistes organiciens est passée d’anecdotique au début des années 60 à prépondérante à l’heure actuelle dans de nombreux domaines de recherche. L’impact le plus spectaculaire de la chimie du fluor sur la société moderne est observé dans l’industrie pharmaceutique où près d’un tiers des nouveaux médicaments sont composés d’au moins un atome de fluor. Par ailleurs, ces composés organofluorés jouent également un rôle crucial dans l’industrie agrochimique via le développement de nouveaux composés bioactifs, dans les sciences médicales par l’emploi de traceurs isotopiques fluorés ou encore dans la science des matériaux via l’étude de matières innovantes utilisant les propriétés physico-chimiques exceptionnelles de l’atome de fluor. Bien que de nombreuses réactions de fluoration aient été décrites au cours des dernières décennies, celles si souffrent de limitations tels que des conditions réactionnelles dures, la difficulté de contrôler la formation du sous-produit, la disponibilité des réactifs de fluoration ou encore la sélectivité. Dans cette optique, nous avons décidés de porter notre attention sur le développement d’une nouvelle méthode de fluoration simple, efficace et utilisant un réactif de départ facile d’accès et stable. Pour se faire, nous avons basés notre stratégie sur l’utilisation d’un intermédiaire ion cétèniminium qui fait a fait l’objet de nombreuses études dans divers groupes de recherche à travers le monde y compris dans notre laboratoire. La stratégie utilisée et développée au cours de cette thèse de doctorat permet, via une réaction monotope de double activation électrophile d’amide, d’obtenir une diversité de composés carbonylés et carboxylés portant un atome de fluor en position α du groupement carbonyle. Ce manuscrit décrira les travaux que nous avons réalisés concernant le développement d’un nouveau procédé de synthèse de composés carbonylés et carboxylés α-fluorés par double activation électrophile d’amides. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

京都大学 / 新制・課程博士 / 博士(薬科学) / 甲第23386号 / 薬科博第143号 / 新制||薬科||16(附属図書館) / 京都大学大学院薬学研究科薬科学専攻 / (主査)教授 川端 猛夫, 教授 高須 清誠, 教授 大野 浩章 / 学位規則第4条第1項該当 / Doctor of Pharmaceutical Sciences / Kyoto University / DFAM

<p> This work was started to investigate new methods of synthesizing certain fulvenes. It was hoped that nucleophilic aromatic substitution of chlorine on 6,6-bis-(p-chlorophenyl) fulvene would provide an alternate route for the preparation of para-substituted 6,6-diphenyl fulvenes which had previously been prepared through the appropriately para-substituted benzophenone and cyclo-pentadienide (1,2). Attempts to prepare these substituted 6,6-diphenylfulvenes were unsuccessful.</p> <p> Secondly, a method of alkylating certain fulvenes in the cyclopentadiene ring was studied. With this in mind, 6,6-diphenylfulvene was treated with various nucleophiles which should give the relatively stable cyclopentadienide intermediate if the base adds to the exocyclic carbon atom. Alkylation of this anion, followed by expulsion of the nucleophilic group and a proton should then generate a new fulvene alkylated in the cyclopentadiene ring. In no case was any alkylated fulvene isolated. The major reaction products were two isomers of benzhydryl cyclopentadiene, rather than the expected alkylated fulvenes. The benzhydryl cyclopentadiene (mixture of two isomers) appears to have resulted from a reduction reaction.</p> <p> Since fulvenes of the type under study are generally unstable, an attempt was made to trap these alkylated fulvenes, if these were present, as their Diels-Alder adducts with tetracyanoethylene (TCNE). This attempt gave the adduct from one of the isomers of benzhydryl cyclopentadiene. The adducts from the other two possible isomers of benzhydryl cyclopentadiene were not detected. This result is an indication of the different reactivities of these isomers to TCNE.</p> <p> From the absence of TCNE adducts of the expected alkylated fulvenes, it was concluded that these fulvenes had not materialized in the attempted alkylation.</p> / Thesis / Master of Science (MSc)

No description available.

Reactions of fluorinated anilines with stoichiometric Ti(NMe2)4 in mesitylene (typically for 23 h at 120 °C) afforded moderate to high yields of the corresponding N,N-dimethyl-o-phenylenediamine derivatives resulting from defluoroamination of a fluorine atom ortho to the NH2 of the starting aniline. Reactivity increased with additional ring fluorination in general accordance with established regiochemical (activating and deactivating) trends. Based on results, we propose a metal-mediated, SNAr-based mechanism. We report the scope and limitations of this reaction and discuss trends in reactivity according to a putative mechanistic scheme. / Master of Science / This thesis describes reactions of fluorinated anilines with titanium amides to make fluorinated 1,2-phenylenediamines. The reaction gives high to moderate yields, and is highly selective for ortho substitution. The scope of the reaction, trends in reactivity among substrates, product characterization, and reaction mechanism are discussed. This reaction is of interest because fluorinated aniline derivatives are a privileged structural motif in pharmaceuticals and agricultural chemicals. The first chapter presents an overview of C-F bond activation and key background information. Chapter 2 is a description of the experiments and an in-depth analysis of their results. Chapter 3 presents detailed characterization data for substances generated in this research. Chapter 4 comprises some concluding remarks and plans for possible future extensions of the research.