HFIP-Promoted Synthesis of Substituted Tetrahydrofurans by Reaction of Epoxides with Electron-Rich Alkenes

In the present work, the employment of fluorinated alcohols, specifically 1,1,1,3,3,3-hexafluoroisopropanol (HFIP), as solvent and promoter of the catalyst-free synthesis of substituted tetrahydrofuranes through the addition of electron-rich alkenes to epoxydes is described. The unique properties of this fluorinated alcohol, which is very different from their non-fluorinated analogs, allows carrying out this new straightforward protocol under smooth reaction conditions affording the corresponding adducts in moderate yields in the majority of cases. Remarkably, this methodology has allowed the synthesis of new tetrahydrofuran-based spiro compounds as well as tetrahydrofurobenzofuran derivatives. The scope and limitations of the process are also discussed. Mechanistic studies were also performed pointing towards a purely ionic or a SN2-type process depending on the nucleophilicity of the alkene employed.This research was funded by the Spanish Ministerio de Economía, Industria y Competitividad (CTQ2015-66624-P and CTQ2017-88171-P) and Spanish Ministerio de Ciencia, Innovación y Universidades (PGC2018-096616-B-I00) and the University of Alicante (UADIF17-27, VIGROB-285, VIGROB-316/19, UADIF19-106) and we would like to thank them for the financial support

Oxidation of Electron-Rich Arenes Using HFIP-UHP System

The straightforward oxidation of electron-rich arenes, namely, phenols, naphthols, and anisole derivatives, under mild reaction conditions, is described by means of the use of an environmentally benign HFIP-UHP system. The corresponding quinones or hydroxylated arenes were obtained in moderate to good yields.We would like to thank the Spanish Ministerio de Economía, Industria y Competitividad (CTQ2015-66624-P and CTQ2017-88171-P), Spanish Ministerio de Ciencia, Innovación y Universidades (PGC2018-096616-B-I00), and the University of Alicante (UADIF17-27, VIGROB-285 and VIGROB-316) for the financial support

Nanomotors for Nucleic Acid, Proteins, Pollutants and Cells Detection

The development of nanomachines able to operate at the nanoscale, performing complex tasks such as drug delivery, precision surgery, or cell detection, constitutes one of the most important challenges in nanotechnology. The principles that rule the nanoscale are completely different from the ones which govern the macroscopic world and, therefore, the collaboration of scientists with expertise in different fields is required for the effective fabrication of these tiny machines. In this review, the most recent advances carried out in the synthesis and application of nanomachines for diagnosis applications will be presented in order to provide a picture of their potential in the detection of important biomolecules or pathogens in a selective and controlled manne

Teoría crítica de la comunicación alternativa para el cambio social. El legado de Paulo Freire y Antonio Gramsci en el diálogo Norte-Sur

Desde su conformación, el campo de la comunicación alternativa para el cambio social ha tendido a apropiarse de manera reduccionista de las reflexiones y experiencias prácticas que desde hace décadas se vienen dando en muchos países de América Latina y de la Europa Mediterránea. En este sentido, las tensiones entre saberes y geopolíticas convierten en objeto prioritario de análisis por cuanto revelan las posibilidades y limitaciones para la construcción de una teoría crítica de la comunicación que ofrezca un justo reconocimiento de las idiosincrasias locales en las que nacen las aportaciones y conceptos. El siguiente artículo está orientado a problematizar y comparar el legado de Paulo Freire y Antonio Gramsci en tanto que promotores de una visión compleja y dialéctica de los mecanismos que atañen a la comunicación participativa en susinteracciones con la cultura masiva y popular.From its origin, the field of the alternative communication for the social change has tended to incorporate the legacy of Latin American and Mediterranean Europe reflections and practical experiences adopting a limited and reductionist perspective. Within this context, the tensions between knowledge and geopolitics become an object of out most importance, since they indicate the possibilities and limitations for the building of a critical communication theory aiming at a fair appreciation of the local idiosyncrasies in which theoretical contributions and concepts are born. The following lines aim at reviewing and comparing the legacy of Paulo Freire and Antonio Gramsci as promoters of a complex and dialectic view of alternative communication and its interactions with massive and popular culture

Comunicação e bom viver. A crítica descolonial e ecológica à comunicação para o desenvolvimento e a mudança social

La cosmovisión del buen vivir promueve un giro biocéntrico y descolonización con respecto a las nociones de comunicación para el desarrollo y para el cambio social. Este artículo plantea un recorrido por la historia de la disciplina con el objeto de incorporar los nuevos debates surgidos en torno al posdesarrollo y la ecología crítica, especialmente a partir de la revalorización de los legados culturales sostenibles silenciados por el binomio modernidad/colonialidad.The world view of living well encourages a biocentric and decolonial change of direction in the ideas on communication for development and for social change. This article provides an overview of the history of the discipline in an effort to include the new debates on post-development and critical ecology, particularly from the standpoint of re-evaluating the sustainable cultural legacies silenced by the modernity/coloniality perspective.A cosmovisão do bom viver promove um giro biocêntrico e descolonial a respeito das noções de comunicação para o desenvolvimento e para a mudança social. Este artigo propõe um percorrido pela história da disciplina com o objetivo de incorporar os novos debates surgidos ao redor do pós-desenvolvimento e da ecologia crítica, especialmente a partir da revalorização dos legados culturais sustentáveis, silenciados pelo binômio modernidade e colonialidade

Direct Synthesis of N,N-Disubstituted Formamides by Oxidation of Imines Using an HFIP/UHP System

The straightforward synthesis of N,N-disubstituted formamides using a combination of 1,1,1,3,3,3-hexafluoroispropanol (HFIP) and H2O2 is described. The unique features of HFIP allowed the utilization of a green oxidant such as H2O2, and the products, arising from an oxidation–rearrangement sequence, were obtained in good to high yields under smooth reaction conditions.We would like to thank the Spanish Ministerio de Economía, Industria y Competitividad (CTQ2015-66624-P and CTQ2017-88171-P), the Spanish Ministerio de Ciencia, Innovación y Universidades (PGC2018-096616-B-I00), and the University of Alicante (VIGROB-316/19, UADIF19-106) for financial support

Análisis de algoritmos para la construcción de arreglo de sufijos en tiempo lineal

El avance en la investigación de los arreglos de sufijos permitió en el año 2003 el planteamiento de tres algoritmos de tiempo lineal para la generación de tales estructuras. Anterior a estos se venía trabajando con algoritmos de orden O(n log n) con probada calidad para la obtención de los arreglos. Desde este punto de partida planteamos la necesidad de conocer experimentalmente el rendimiento de los algoritmos O(n) frente a los de orden O(n log n) y conocer entre los planteados de orden n cual es el mejor en términos de tiempo de ejecución y uso de recursos computacionales. Después de un profundo trabajo de investigación, pruebas y análisis en el laboratorio podemos concluir basados en los resultados experimentales y los criterios de tiempo y recursos que los algoritmos O(n log n) en este caso alcanzan un mejor rendimiento que los O(n

The Empirics of the Labour Theory of Value: Reply to Nitzan and Bichler

empirical verification and Marxist theory labour theory of value spurious correlationThe labor theory of value, originated in the classics and reformulated by Marx, has found support in numerous empirical works during the last thirty years. In many economies, sectors in monetary terms are highly correlated with them in terms of labor values. In his book Capital as Power (2009), and in a subsequent discussion online, Jonathan Nitzan and Shimshon Bichler argue that such results are invalid because the calculations do not use labor value variables but two monetary variables are correlated. Nitzan and Bichler also argue that are spurious correlations by the presence of a third variable. This article refutes both critics and consequently reinforces the empirical support for the theory of labor value. [For the original exchange, see: "Testing the Labour Theory of Value: An Exchange" here: http://bnarchives.yorku.ca/308/

Overcoming the stability, toxicity, and biodegradation challenges of tumor stimuli-responsive inorganic nanoparticles for delivery of cancer therapeutics

Introduction: Stimuli-responsive nanomaterials for cancer therapy have attracted much interest recently due to their potential for improving the current standard of care. Different types of inorganic nanoparticles are widely employed for the development of these strategies, but in some cases safety concerns hinder their clinical translation. This review aims to provide an overview of the challenges that inorganic nanoparticles face regarding their stability, toxicity and biodegradability, as well as the strategies that have been proposed to overcome them. Areas covered: The available information about the in vitro and in vivo biocompatibility, as well as the biodegradability of the following nanoparticles is presented and discussed: superparamagnetic iron oxide nanoparticles, gold nanoparticles, graphene and mesoporous nanoparticles made of silicon or silicon oxide. The toxicology of inorganic nanoparticles is greatly affected by many physicochemical parameters, and their surface modification emerges as the main intervention to improve their biocompatibility and tailor their performance for specific biomedical applications. Expert opinion: Even though many different studies have been performed regarding the biological behavior of inorganic nanoparticles, long-term in vivo data is still scarce, limiting our capacity to evaluate the proposed nanomaterials for clinical use. The role of biodegradability in different therapeutic contexts is also discussed

Graphene Oxide-Supported Oxime Palladacycles as Efficient Catalysts for the Suzuki–Miyaura Cross-Coupling Reaction of Aryl Bromides at Room Temperature under Aqueous Conditions

Palladacycles are highly efficient precatalysts in cross-coupling reactions whose immobilization on carbonaceous materials has been hardly studied. Herein, we report a detailed study on the synthesis and characterization of new oxime palladacycle-graphene oxide non-covalent materials along with their catalytic activity in the Suzuki–Miyaura reaction. Catalyst 1-GO, which has been fully characterized by ICP, XPS, TGA, and UV-Vis analyses has been demonstrated to be an efficient catalyst for the Suzuki–Miyaura coupling between aryl bromides and arylboronic acids using very low catalyst loadings (0.002 mol % of Pd) at room temperature under aqueous conditions.Financial support from the University of Alicante (UAUSTI16-03, UAUSTI16-10, VIGROB-173), the Spanish Ministerio de Economía, Industria y Competitividad (CTQ2015-66624-P) is acknowledged