Search results for "accions"
showing 10 items of 70 documents
Organocatalytic Enantioselective Functionalization of Hydroxyquinolines through an Aza-Friedel-Crafts Alkylation with Isatin-derived Ketimines
2018
[EN] A highly enantioselective addition of hydroxyquinolines to isatin-derived ketimines has been realized using a quinine-derived thiourea organocatalyst. The reaction affords chiral 3-amino-2-oxindoles bearing a quinoline moiety with a quaternary stereocenter in high yields (up to 98%) and excellent enantioselectivities (up to 99%). Moreover, we can extend this methodology for the enantioselective functionalization of 5-hydroxyisoquinoline. This methodology represents, to the best of our knowledge, the first enantioselective addition of hydroxyquinolines to imines.
Organocatalytic Enantioselective Friedel-Crafts Alkylation of 1-Naphthol Derivatives and Activated Phenols with Ethyl Trifluoropyruvate
2015
An organocatalytic enantioselective Friedel–Crafts alkylation of a series of substituted 1- naphthol derivatives and activated phenols with ethyl trifluoropyruvate, catalyzed by a quinine-derived squaramide, is presented. Good yields and high to excellent enantioselectivities of the Friedel– Crafts alkylation products were obtained.
N-glycosylation efficiency is determined by the distance to the C-terminus and the amino acid preceding an Asn-Ser-Thr sequon
2011
N-glycosylation is the most common and versatile protein modification. In eukaryotic cells, this modification is catalyzed cotranslationally by the enzyme oligosaccharyltransferase, which targets the β-amide of the asparagine in an Asn-Xaa-Ser/Thr consensus sequon (where Xaa is any amino acid but proline) in nascent proteins as they enter the endoplasmic reticulum. Because modification of the glycosylation acceptor site on membrane proteins occurs in a compartment-specific manner, the presence of glycosylation is used to indicate membrane protein topology. Moreover, glycosylation sites can be added to gain topological information. In this study, we explored the determinants of N-glycosylati…
SN1 Reactions in Supercritical Carbon Dioxide in the Presence of Alcohols: the Role of Preferential Solvation
2016
Ethanol (3b) inhibits SN1 reactions of alkyl halides 1 in supercritical carbon dioxide (scCO2) and gives no ethers as products. The unexpected behaviour of alcohols 3 in the reaction of alkyl halides 1 with 1,3-dimethoxybenzene (2) in scCO2 under different conditions is rationalised in terms of Bronsted and Lewis acid–base equilibria of reagents, intermediates, additives and products in a singular solvent characterised by: (i) the strong quadrupole and Lewis acid character of carbon dioxide, which hinders SN2 paths by strongly solvating basic solutes; (ii) the weak Lewis base character of carbon dioxide, which prevents it from behaving as a proton sink; (iii) the compressible nature of scCO…
Enseñanza de las ciencias : revista de investigación y experiencias didácticas
1996
Resumen basado en el de la publicación Resumen en inglés La evolución histórica del principio de Le Chatelier está relacionada con su uso en el aula de química. La aparente simplicidad en la cual el principio de Le Chatelier fue formulado por primera vez y el éxito logrado en la implementación de algunos procesos industriales importantes le dio un reconocimiento inicial que aún perdura. Sin embargo, desde el comienzo de este siglo, diferentes autores han señalado el carácter limitado de la regla cualitativa y su formulación vaga y ambigua. Además, la termodinámica dada por el Principio de Le Chatelier en algunas formulaciones cuantitativas limitan su aplicabilidad. Sin embargo, la mayoría d…
Teoria del finançament: part pràctica
2013
El document forma part dels materials docents programats mitjançant l'ajut del Servei de Política Lingüística de la Universitat de València. Els continguts d'aquesta matèria complixen amb les exigències de la guia académica de la matèria: Teoria del finançament del Grau en Administració y Direcció d'Empreses (GADE). The contents of this course meet the academic requirements of the Guide: Theory of Financing degree in business management and Administration.
Teoria del finançament: part teòrica
2013
El document forma part dels materials docents programats mitjançant l'ajut del Servei de Política Lingüística de la Universitat de València. Els continguts d'aquesta matèria complixen amb les exigències de la guia académica de la matèria: Teoria del finançament del Grau en Administració y Direcció d'Empreses (GADE). The contents of this course meet the academic requirements of the Guide: Theory of Financing degree in business management and Administration.
Materials docents de l'assignatura Intervenció administrativa en les relacions laborals
2014
Aquest material docent ha rebut l'ajut del Servei de Política Lingüística de la Universitat de València Presentacions de l'assignatura Intervenció administrativa en les relacions laborals del Grau en Relacions Laborals i Recursos Humans
Les activitats no són accions (situacions i tipus de text en anglès i en català)
2001
[ENG] This paper seeks to show that Activities do not form a natural class with neither Actions nor States. We suggest that these categories are not objective situation classes, but different (subjective) ways of conceptualizing the dynamics and the discreteness of a given situation. Having been a situation conceptualized as an Action, an Activity or a State (non-discrete o discrete), the discourse chunk which represents it is organized according to a particular mode or textual type which reflects the speaker perspective: a narrative, an exposition of activities, an exposition of states, or a description. Provided that Activities determine one particular way of organizing the discourse stru…
Les accions protectores de la propietat
2021
El document forma part dels materials docents programats mitjançant l'ajut del Servei de Política Lingüística de la Universitat de València. Power-point on s'expliquen les iderents accions de què disposa el titular per defensar el seu dret de propietat, tant front als què s'ho neguen com front a qualsevol que realitza actuacions que comprometen la seua integritat.