Search results for "Arrangements"
showing 10 items of 66 documents
Synthesis of Fluorinated Indazoles Through ANRORC-Like Rearrangement of 1,2,4-Oxadiazoles with Hydrazine.
2006
A series of 6-substituted fluorinated indazoles has been obtained through an ANRORC-like rearrangement (Addition of Nucleophile, Ring-Opening and Ring-Closure) of 5-tetrafluorophenyl-1,2,4-oxadiazoles with hydrazine. The initial addition of the bidentate nucleophile to the electrophilic C(5) of the 1,2,4-oxadiazole ring, followed by ring opening and ring closure, leads to the formation of fluorinated indazoles in high yield under mild experimental conditions. Functionalization of the C(6) in the final indazole nucleus was preliminarily achieved through a nucleophilic aromatic substitution on the starting 5-pentafluorophenyl-1,2,4-oxadiazole.
Radical addition to iminium ions and cationic heterocycles
2014
Carbon-centered radicals represent highly useful reactive intermediates in organic synthesis. Their nucleophilic character is reflected by fast additions to electron deficient C=X double bonds as present in iminium ions or cationic heterocycles. This review covers diverse reactions of preformed or in situ-generated cationic substrates with various types of C-radicals, including alkyl, alkoxyalkyl, trifluoromethyl, aryl, acyl, carbamoyl, and alkoxycarbonyl species. Despite its high reactivity, the strong interaction of the radical’s SOMO with the LUMO of the cation frequently results in a high regioselectivity. Intra- and intermolecular processes such as the Minisci reaction, the Porta react…
Fluorinated Heterocyclic Compounds. An Effective Strategy for the Synthesis of Fluorinated Z-Oximes of 3-Perfluoroalkyl-6-phenyl-2H-1,2,4-triazin- 5-…
2005
The reaction of 3-benzoyl-5-perfluoroalkyl-1,2,4-oxadiazoles with hydrazine has been investigated, evidencing the possibility of competitive reaction paths. Nucleophilic addition of the hydrazine to the electrophilic C(5) of the 1,2,4-oxadiazole ring, followed by ring opening and ring closure with enlargement, leads with high yield and in very mild experimental conditions to the formation of Z-oximes of 3-perfluoroalkyl-6-phenyl-2H-1,2,4-triazin-5-ones (11a-c) as major products of the reaction. In turn, the hydrazine can attack the electrophilic carbonyl carbon giving 4-perfluoroacylamino-5-phenyl-2H-1,2,3-triazoles (13a-c) through the well-known Boulton-Katritzky rearrangement of the inter…
Human papillomavirus:Its identikit and controversial role in oral oncogenesis,premalignant an malignant lesions(Review)
2007
Human papillomaviruses (HPVs) are a group of host-specific DNA viruses, with a remarkable epithelial cell specificity: they have been reported principally in the ano-genital tract, urethra, skin, larynx, tracheo-bronchial and oral mucosa. More than 100 different HPV types have been identified and classified as high (e.g. 16, 18, 31) or low (e.g. 11, 42, 36) -risk (HR and LR), based on their association with cervical carcinoma. The carcinogenic role of HR-HPV revolves mainly around two of its oncoproteins: HPV-E6 which promotes degradation of the p53 tumour suppressor gene product and HPV-E7 which modifies the pRb tumour suppressor gene product, inhibiting the activity of TGF-beta2. Since th…
Court Interpreting 2009: an undervalued and misunderstood profession? Or: will justice speak?
2010
The article addresses a number of topical issues relating to court interpreting. After examining a number of issues discussed among US interpreters in July 2009, it considers the provision of court interpreting in a number of different English-speaking jurisdictions, including the position of agencies. It presents the cost of a lack of judicial awareness of the issues involved in providing competent interpreting in legal proceedings, and looks at how rare languages are dealt with in the United States. It examines best practice and how this can quickly turn into worst practice. It considers the situation in Canada’s Province of Ontario, where a class action has been brought against the Minis…
IMF lending arrangements in emerging and developing countries – participation and prediction
2016
AbstractThe literature on determinants of International Monetary Fund (IMF) interventions in emerging and developing countries shows that the IMF’s decisions are determined by political and economic causes. This article empirically investigates economic factors, showing that a country’s probability to sign an IMF arrangement can be predicted by looking at a core group of macroeconomic variables. Using discriminant analysis we develop a score function that allows us to predict a country’s future participation in IMF programmes. The study covers 153 emerging and developing countries, over more than 30 years (1980–2011) and 654 agreements, for both non-concessional and concessional loans. The …
Pan-cancer analysis of whole genomes
2020
Publisher's version (útgefin grein)
A symmetrization result for Monge–Ampère type equations
2007
In this paper we prove some comparison results for Monge–Ampere type equations in dimension two. We also consider the case of eigenfunctions and we derive a kind of “reverse” inequalities. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
On the reaction of some 5-polyfluoroaryl-1,2,4-oxadiazoles with methylhydrazine: synthesis of fluorinated indazoles
2009
The reaction of 5-polyfluoroaryl-1,2,4-oxadiazoles with methylhydrazine has been studied and the synthesis of fluorinated N-methylindazoles has been realized. Rearrangement reactions showed predominantly formation of N(1)-methylindazole regioisomers. Starting compounds were preliminarily functionalized at the polyfluoroaryl moiety through fluorine displacement with nucleophiles (methanol, methylamine, dimethylamine), allowing the obtainment of target indazoles substituted at the C(6) position.
Network governance arrangements and rural-urban synergy
2021
Increasing attention has been paid to the importance of balanced rural–urban interaction to sustainable regional development. Yet, our knowledge on the elements of network governance for such interaction is scarce. The aim of this paper is to study what kind of network governance arrangements currently exist, how they can be improved, and whether evolutionary governance paths can be identified. We analyse five existing and evolving cases of functioning rural–urban interaction in European Union (EU) member states, using a network governance framework as an analytical lens. We supplement the governance analysis with examining what kind of spatial understanding or combination of di…