[Ag(PcL)]-Catalysed Domino Approach to 6-Substituted Benzoxazino Isoquinolines

In this paper, we describe a new silver catalysed domino approach to 6-substituted benzoxazino isoquinolines starting from 2-alkynylbenzaldehydes and 1-substituted-(2-aminophenyl)methanols. The strategy is characterized by good reaction yields, and can be performed at room temperature as well as under heating (conventional or dielectric) in different reaction times. Best results have been obtained by using silver complexes of macrocyclic pyridine-containing ligands (PcL) as catalysts. The stereoselectivity of the transformation has been investigated by using chiral reaction partners and chiral catalyst, but unfortunately, modest stereoselectivities has been achieved. On the other hand, this approach represents an alternative synthetic strategy for the preparation of 6-substituted benzoxazino isoquinolines, which are the key scaffold of some compounds endowed of biological activity

Cycloaddition reactions of 1,3-diazabuta-1,3-dienes with alkynyl ketenes

The cycloaddition reactions of "all-carbon" 1,3-diazabuta-1,3-dienes with a few conjugated and unconjugated alkynyl ketenes are described. The reactions provide some interesting azetidinones and dihydropyrimidinones bearing an alkynyl moiety. The regiochemistry of cycloadduct is related with the degree of conjugation of the alkynyl ketene. Moreover, two alternative approaches to "all-carbon" 1,3-diazabuta-1,3-dienes are reported

SILVER CATALYSED INTRAMOLECULAR CYCLISATION OF 2-ALKYNYL-ACETOPHENONES AND 3-ACETYL-2-ALKYNYLPYRIDINES IN THE PRESENCE OF AMMONIA

The development of new domino approaches for the synthesis of nitrogen containing heterocycles is a research field in continuous evolution. In particular, for many years we have been interested in the synthesis of nitrogen containing rings starting from alkyne derivatives in the presence of ammonia. Recently we reported a valuable approaches to the synthesis isoquinolines starting from 2-alkynyl-benzaldehydes,2 and the approach was also successfully transformed in a multicomponent process.3 Unexpectedly, when we tried to react 2-alkynylacetophenone derivatives under optimized conditions the reaction failed. This result prompt us to investigate the reaction of alkynyl ketones more in depth. We started our study looking for the best conditions to trigger the domino reaction on a model compound. We tried some metal catalysts potentially able to promote both the imine formation as Lewis acid, and the intermolecular hydroamination step as alkynophilic catalysts.4 We were delighted to find that the metal catalysed reaction gave the desired isoquinoline, beside variable amounts of the isomeric naphthalen-1-amine. The best results were obtained with AgOTf in terms of conversion, selectivity and reaction times. Scope and limitation of the approach have been extensively studied. We found that the silver-catalyzed/microwave-promoted domino imination/annulation of alkynes bearing a proximate carbonyl group in the presence of ammonia is an interesting alternative for the synthesis of aromatic heterocycles and carbocycles. A plausible mechanism is also suggested

Evaluación de la producción de carne de ganado criollo patagónico

Objetivo. Evaluar la producción de carne del ganado Criollo Patagónico respecto al Angus y cruzas entre ambas razas. Materiales y métodos. Se dispuso de una muestra de 42 animales de los genotipos Criollo Patagónico, Angus y cruza entre ambos, clasificados en novillitos o vaquillonas, terminados en feed lot durante un período de 114 y 156 días, a partir de los cuales se conformaron ocho grupos de análisis desbalanceados. Para la parte exploratoria se empleó análisis factorial. Se usaron modelos lineales mixtos para contemplar las correlaciones entre las mediciones sobre un mismo animal. Resultados. Se pudo constatar diferencias entre las medias de los pesos a faena de los dos períodos de engorde y que esta ganancia de peso se depositó en los cortes de menor valor comercial. Con relación al rendimiento de los cortes de alto valor económico, se detectó interacción entre éstos y los grupos, identificándose diferencias entre grupos para algunos de los cortes. Conclusiones. En virtud de los resultados obtenidos, se considera promisoria la producción de carne del ganado Criollo Patagónico con relación al rendimiento de los cortes de alto valor económico, pues sus rendimientos medios sólo se vieron superados en bife ancho por su cruza con Angus

The Utility of Physiological Measures in Assessing the Empathic Skills of Incarcerated Violent Offenders.

Since lack of empathy is an important indicator of violent behaviors, researchers need consistent and valid measures. This study evaluated the practical significance of a potential physiological correlate of empathy compared to a traditional self-report questionnaire in 18 male violent offenders and 21 general population controls. Empathy skills were assessed with the Interpersonal Reactivity Index (IRI) questionnaire. Heart-Rate Variability (HRV) was assessed with an electrocardiogram. The RMSSD (Root Mean Square of the Successive beat-to-beat Differences), an HRV index implicated in social cognition, was calculated. There were no group differences in IRI scores. However, RMSSD was lower in the offender group. Positive correlations between RMSSD and IRI subscales were found for controls only. We conclude that psychometric measures of empathy do not discriminate incarcerated violent offenders, and that the incorporation of psychophysiological measures, such as HRV, could be an avenue for forensic research on empathy to establish translatable evidence-based information

Liver X receptors, nervous system, and lipid metabolism

Lipids in the nervous system are represented by cholesterol and phospholipids as constituents of cell membranes and, in particular, of myelin. Therefore, lipids are finely regulated to guarantee physiological functions. In the central nervous system, cholesterol is locally synthesized due to the presence of the blood brain barrier. In the peripheral nervous system cholesterol is either up-taken by lipoproteins and/or produced by de novo biosynthesis. Defects in lipid homeostasis in these tissues lead to structural and functional changes that often result in different pathological conditions depending on the affected pathways (i.e. cholesterol biosynthesis, cholesterol efflux, fatty acid biosynthesis etc.). Alterations in cholesterol metabolism in the central nervous system are linked to several disorders such as Alzheimer's disease, Huntington disease, Parkinson disease, Multiple sclerosis, Smith-Lemli-Opitz syndrome, Niemann-Pick type C disease, and glioblastoma. In the peripheral nervous system changes in lipid metabolism are associated with the development of peripheral neuropathy that may be caused by metabolic disorders, injuries, therapeutics, and autoimmune diseases. Transcription factors, such as the Liver X receptors (LXR), regulate both cholesterol and fatty acid metabolism in several tissues including the nervous system. In the last few years several studies elucidated the biology of LXR in the nervous system due to the availability of knock-out mice and the development of synthetic ligands. Here, we review a survey of the literature focused on the central and peripheral nervous system and in physiological and pathological settings with particular attention to the roles played by LXR in both districts

Silver Catalyzed Domino Approach to 1,3-Dicarbosubstituted Isochromenes

We report herein the first example of the silver triflate catalysed synthesis of 1,3-dicarbo-substituted isochromene derivatives starting from 2-alkynyl(hetero)arylaldehydes and enolizable ketones. The reaction proceeds in a cascade fashion under mild heating with complete regioselectivity and moderate-to-good yields. In some cases, the reaction gives unexpected homodimeric products. Two competitive mechanistic paths for the formation of the desired isochromene derivatives and the homodimeric products are described

Evaluation of the application of not traumatic linking and learning techniques in two races of horses

Existe un conjunto de prácticas que permiten la familiarización del potrillo con el entorno, además de facilitar la detección y el diagnóstico de enfermedades, malformaciones y/o lesiones posparto (Gónzalez del Pino et al, 2009). Se conocen como Técnicas de Vinculación y Aprendizaje no Traumáticas (TVANT) y son realizadas mediante un contacto diario, tanto con el potrillo como con su madre, implicando una revisión habitual a cada individuo desde el día 7 al 14 desde el nacimiento. Nuestra experiencia en raza Criolla ha mostrado que las TVANT producen resultados satisfactorios (Abbiati et al, 2016). El objetivo de este trabajo fue comparar la duración del proceso para las razas Criolla y Silla Argentino en las maniobras de las TVANT.Facultad de Ciencias Veterinaria

Silver comes into play: Henry reaction and domino cycloisomerisation sequence catalysed by [Ag(I)(Pc-L)] complexes

We report herein the synthesis of new pyridine-containing macrocyclic ligands (Pc-L) bearing a non-innocent pendant arm, by exploiting both chiral and functional properties of natural amino acids. The obtained macrocyclic ligands were employed to synthesize well-defined cationic silver(I) complexes that were shown to be competent catalyst for the Henry (nitroaldol) reaction. Good to excellent yields and full selectivity in the b-nitroalcohol product were obtained starting from electron-poor aromatic aldehydes or other activated aldehydes such as furfural under mild reaction conditions. The straightforward synthesis of the macrocyclic ligands starting from cheap commercially available starting materials allowed for the introduction of a suitable basic functionality into the ligand pendant arm, thus providing a bifunctional catalyst. Based on our previous experience in [Ag(I)(Pc-L)] catalysed domino addition/cycloisomerisation reaction of o-alkynylbenzaldheydes and nucleophiles, the synthesis of isochromenes coupling the Henry reaction and the cycloisomerisation in a single step was subsequently explored. Although with low selectivity, [Ag(I)(Pc-L)] cationic complexes were able to promote such a cascade reaction and a possible mechanism based on experimental evidences has been proposed

Ecosystem processes: litter breakdown patterns in Mediterranean and Black Sea transitional waters

1 - Leaf litter decomposition rates, in aquatic ecosystems, are known to be related to many different abiotic and biotic factors. 2 - Here, we focus on the influence of abiotic factors, searching for patterns of reed litter decay rates on gradient of physiographic, hydrological and physico-chemical components of transitional water ecosystems. 3 - Field experiments were carried out in 16 water ecosystems in the Eastern Mediterranean and Black Sea in spring 2005. 4 - Significant differences of leaf litter decomposition were observed among ecosystems along univariate gradient of tidal range, index of sinuosity, water temperature and salinity. At least 71% of variance in the litter breakdown rate was explained by the considered abiotic factors. 5 - It is concluded that, at the macro-ecological scale of study, some key abiotic factors, such as tidal range and salinity, are suggested to play a major role as drivers of plant detritus decomposition processes. 6 - The relevance of the described abiotic drivers as descriptor of the most commonly used classification schemes for transitional water ecosystems (i.e., Confinement and Venice System classifications), is a further support to their role as environmental forcing factors