Enantioselective conjugate addition of ketones to β-nitrostyrenes catalyzed by 1,2-amino alcohol-derived prolinamides

Various l-prolinamides 14, prepared from l-proline and chiral β-amino alcohols, are active bifunctional catalysts for the direct nitro-Michael addition of ketones to β-nitrostyrenes. In particular, catalyst 14e prepared from l-proline and (1S,2R)-cis-1-amino-2-indanol exhibits the highest catalytic performance working in polar aprotic solvents such as NMP. High syn-diastereoselectivities (up to 94% de) and good enantioselectivities (up to 80% ee) were obtained at rt.This work has been supported by the Dirección General de Investigación of the Ministerio de Educación y Ciencia (CTQ2004-00808/BQU), by the Generalitat Valenciana (CTIOIB/2002/320, GRUPOS03/134, GRUPOS05/11 and GV05/157) and the University of Alicante

Predictive Model for Taking Decision to Prevent University Dropout

Dropout is an educational phenomenon studied for decades due to the diversity of its causes, whose effects fall on society's development. This document presents an experimental study to obtain a predictive model that allows anticipating a university dropout. The study uses 51,497 instances with 26 attributes obtained from social sciences, administrative sciences, and engineering collected from 2010 to 2019. Artificial neural networks and decision trees were implemented as classification algorithms, and also, algorithms of attribute selection and resampling methods were used to balance the main class. The results show that the best performing model was that of Random Forest with a Matthew correlation coefficient of 87.43% against 53.39% obtained by artificial neural networks and 94.34% accuracy by Random Forest. The model has allowed predicting an approximate number of possible dropouts per period, contributing to the involved instances in preventing or reducing dropout in higher education

Microwave-Promoted Copper-Free Sonogashira–Hagihara Couplings of Aryl Imidazolylsulfonates in Water

Aryl imidazol-1-ylsulfonates have been efficiently cross-coupled with aryl-, alkyl-, and silylacetylenes in neat water under copper-free conditions at 110 °C assisted by microwave irradiation. Using 0.5 mol% of an oxime palladacycle as precatalyst, 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl (SPhos, 2 mol%) as ligand, hexadecyltrimethylammonium bromide (CTAB) as additive, and triethylamine (TEA) as base, a wide array of disubstituted alkynes has been prepared in good to high yields in only 30 min.Financial support from the MICINN (Projects CTQ2007-62771/BQU, CTQ2010-20387 and Consolider INGENIO 2010 CSD2007-00006), FEDER, from the Generalitat Valenciana (Project PROMETEO/2009/038), and the University of Alicante is acknowledged

Some Lessons for the Future from the Global Malaria Eradication Programme (1955–1969)

Jose Najera and colleagues identify lessons from the Global Malaria Eradication Programme (1955–1969) relevant to current elimination and eradication efforts

Microwave-assisted palladium-catalyzed highly regio- and stereoselective head to head dimerization of terminal aryl alkynes in water

A highly regio- and stereoselective oxime palladacycle/imidazolinium-catalyzed head to head dimerization of terminal aryl alkynes in water is presented. The reaction, which is carried out at 130 °C under microwave irradiation in the presence of 1,3-bis-(2,6-diisopropylphenyl)imidazolinium chloride as ligand, triethylamine as base, and TBAB as surfactant, allows the synthesis of (E)-1,4-enynes as single stereoisomers in good isolated yields.Financial support from the MINECO (CTQ2010-20387), the Generalitat Valenciana (PROMETEO/2009/038), and the University of Alicante (VIGROB-173, UAUSTI13-01) is acknowledged

Copper-Free Oxime–Palladacycle-Catalyzed Sonogashira Alkynylation of Deactivated Aryl Bromides and Chlorides in Water under Microwave Irradiation

Palladium-catalyzed Heck alkynylation cross-coupling reactions between terminal alkynes and deactivated aryl chlorides and aryl bromides can be performed in the absence of copper cocatalyst with water as solvent at 130 °C under microwave irradiation. An oxime-derived chloro-bridged palladacycle is an efficient precatalyst for this transformation with 2-dicyclohexylphosphanyl-2′,4′,6′-triisopropylbiphenyl (XPhos) as ancillary ligand, pyrrolidine as base, and SBDS as surfactant. All of the reactions can be performed under air and with reagent-grade chemicals under low loading conditions (0.1–1 mol-% Pd).Financial support from the Ministerio de Economía y Competitividad (MINECO) (project CTQ2010-20387), Consolider INGENIO (project 2010 CSD2007-00006), Fondos Europeos para el Desarrollo Regional (FEDER), the Generalitat Valenciana (project PROMETEO/2009/038), and the University of Alicante is acknowledged

Finishing Effect on Fatty Acid Profile of Intramuscular Fat in Extensively Reared Steers

Both the amount and the composition of fat depots in beef may be influenced by several factors i.e. feeding system. Related to this factor, extensively reared cattle may produce beef with a more desirable fatty acid (FA) composition in terms of beneficial effect on human health, especially in relation to the content of n-3 type FAs. However, concentrate finishing improves some carcass traits and meat quality. In this sense, the objective of this work was to study the effect of concentrate finishing on intramuscular (IM) FA profile of Longissimus thoracis (LT) muscle in pasture fed steers