Search results for "Tertiary"
showing 10 items of 573 documents
Water compatible gold(III)-catalysed synthesis of unsymmetrical ethers from alcohols.
2008
An efficient and broad-scoped method for the preparation of unsymmetrical ethers from alcohols catalysed by the simplest and least expensive gold catalyst, NaAuCl 4 , is described for the first time. The procedure enables the etherification of benzylic and tertiary alcohols with moderate to good yields under mild conditions with low catalyst loading. Symmetrical ethers, the usual side products in the etherification of alcohols, were not detected in this case. The formation of the racemic ether from a chiral benzyl alcohol suggests the intermediacy of a carbocation, which has not previously been postulated for gold-catalysed reactions involving alcohols.
Organocatalysts Fold to Generate an Active Site Pocket for the Mannich Reaction
2017
Catalysts containing urea, thiourea and tertiary amine groups fold into a three-dimensional organized structure in solution both in the absence as well as in the presence of substrates or substrate analogues, as indicated by solution NMR and computational studies. These foldamer catalysts promote Mannich reactions with both aliphatic and aromatic imines and malonate esters. Hammett plot and secondary kinetic isotope effects provide evidence for the C-C bond forming event as the turnoverlimiting step of the Mannich reaction. Computational studies suggest two viable pathways for the C-C bond formation step, differing in the activation modes of the malonate and imine substrates. The results sh…
Determination of basic strenght of aliphatic amines through ion pair formation in some ionic liquid solutions
2010
To have an evaluation of the basic strength of aliphatic amines in ionic liquid solution, the stability constants relevant to the formation of amine/p-nitrophenol ion pairs were determined in different ionic liquids at 298 K. In particular, aliphatic (pyrrolidinium) and aromatic (imidazolium) ionic liquids were used. Imidazolium ions, bmim(+) and bm(2)im(+), having different hydrogen bond donor abilities were taken into account. Anions were chosen ([BF(4)(-)], [PF(6)(-)], and [NTf(2)(-)]; where NTf(2) = bis(trifluoromethansulfonyl)imide) showing different shape, size, and coordination ability. Several primary, secondary (cyclic or not), and tertiary amines were used to study the effect of a…
Suomalaisten yliopistojen ja korkeakoulupolitiikan juurilla
2019
Arvio teoksesta Välimaa, Jussi. Opinteillä oppineita. Suomalainen korkeakoulutus keskiajalta 2000-luvulle. University Press of Eastern Finland. 2018. 387 s. ISBN 978-952-5934-96-0. nonPeerReviewed
Students’ perspectives on English medium instruction within higher education. Exploring gender differences in Norway and Finland
2020
This study aims to explore gender differences in students’ perspectives on language use within higher education (HE), using data from a survey distributed to students at two universities in Norway and Finland. Analysing responses concerning language use in HE, I found that most students were positively inclined towards English medium instruction (EMI). However, while there in both countries were only small differences in attitudes towards EMI between male and female students, in Finland, female students were less confident in their English skills than male students were. Furthermore, female students in both countries reported more difficulties in coping with English in their day-to-day stud…
La educación en casa o homeschooling: la STC de 2 de diciembre de 2010
2011
[EN] This article analyses raising conflicts between children ́ education ́s right and freedom of education belonging to parents and tutors, according to the complex article 27 of Spanish Constitution, especially after the recent sentence of Constitucional Court dated from 2nd December 2010, all of this in relation with the possiblility of giving basic education not through compulsory education but homeschooling.
Virulence factor rtx in Legionella pneumophila, evidence suggesting it is a modular multifunctional protein
2008
Abstract Background The repeats in toxin (Rtx) are an important pathogenicity factor involved in host cells invasion of Legionella pneumophila and other pathogenic bacteria. Its role in escaping the host immune system and cytotoxic activity is well known. Its repeated motives and modularity make Rtx a multifunctional factor in pathogenicity. Results The comparative analysis of rtx gene among 6 strains of L. pneumophila showed modularity in their structures. Among compared genomes, the N-terminal region of the protein presents highly dissimilar repeats with functionally similar domains. On the contrary, the C-terminal region is maintained with a fashionable modular configuration, which gives…
New Insights into the complexation of lead(II) by 1,4,7,10-tetrakis(carbamoylmethyl)-1,4,7,10-tetraazacyclododecane (DOTAM): structural, thermodynami…
2007
The lead(II) coordination properties of the tetrapodal ligand DOTAM [1,4,7,10-tetrakis(carbamoylmethyl)-1,4,7,10-tetraaza-cyclododecane] have been investigated both in the solid state and in solution in order to ascertain the stereoactivity of the lone pair and to rationalize the structural effects of a cyclen-based scaffold on the metal uptake kinetics. The crystal structure of the free base shows that the pendant acetamide groups are not equivalent: two are folded over the macrocycle and maintained by an intramolecular hydrogen bond involving an amide hydrogen atom and a neighboring tertiary amine of the cyclen ring, while the other two are extended and point away from the macrocyclic cav…
Leksiskā pieeja lietišķās angļu valodas sarakstes prasmju pilveidei augstskolā
2021
Šabloniskās valodas lietojums lietišķajā komunikācijā palīdz ziņu padarīt īsāku un skaidrāku, kas ir svarīgi, lai panāktu veiksmīgas biznesa attiecības un sasniegtu komunikatīvos mērķus. Mērķis bija izpētīt, cik efektīvi būtu piemērot leksisko pieeju mācot vēstuļu rakstīšanu lietišķās angļu valodas kontekstā. Pielietotā pētniecības metode bija gadījuma izpēte. Datu iegušanas metodes bija aptaujas un testi. Pētījuma dalībnieki bija trīsdesmit pilna laika bakalaura līmeņa studenti, kas apguva programmu vienā no universitātēm Latvijā. Visiem dalībniekiem angļu valoda bija svešvaloda. Secinājumi norādīja, ka leksiskā pieeja kā metodoloģiskā stratēģija pozitīvi ietekmēja šabloniskās valodas liet…
The C-terminal antibody binding domain ofCandida albicansmp58 represents a protective epitope during candidiasis
2003
The 58-kDa surface mannoprotein of Candida albicans (mp58) elicits strong antibody responses during infection. Epitope mapping with sera from patients with candidiasis and control individuals indicated the presence of multiple IgG-reactive continuous epitopes on the protein, expanding both the amino- and carboxy-terminal domains and several internal regions. These immunoreactive regions were similar to the ones previously identified using sera from immunized animals. Two of the epitopic regions (including the C-terminal domain) showed increased reactivity with antibodies present in sera from patients with candidiasis as compared to control individuals. Patients who survived the infection di…