Indium-Mediated Cleavage of the Trityl Group from Protected 1H-Tetrazoles

On treatment with indium metal in MeOH–THF, trityl groups undergo reductive removal from 1H-protected tetrazoles (including aliphatic, aromatic, and heteroaromatic substituents), affording the corresponding free tetrazoles in excellent yields, without any decomposition of the tetrazole ring or reduction of any other group.

Catalytic Asymmetric Transfer Hydrogenation of Imines: Recent Advances

In this review article recent developments in the asymmetric transfer hydrogenation of imines from 2008 up to today are presented. The main methodology involves either metal-catalyzed procedures in the presence of a chiral ligand or organocatalyzed technologies using a Hantzsch ester and a chiral BINOL-derived phosphoric acid. The most important procedures are collected, paying special attention to the application of this methodology in synthetic organic chemistry.

Recent Advances in the Direct Nucleophilic Substitution of Allylic Alcohols through SN1-Type Reactions

Direct nucleophilic substitution reactions of allylic alcohols are environmentally friendly, since they generate only water as a byproduct, allowing access to new allylic compounds. This reaction has, thus, attracted the interest of the chemical community and several strategies have been developed for its successful accomplishment. This review gathers the latest advances in this methodology involving SN1-type reactions.

Synthesis of 5-Carbapterocarpens by α-Arylation of Tetralones Followed by One-Pot Demethylation/Cyclization with BBr3

5-Carbapterocarpens, one of them displaying estrogenic activity, were prepared from α-aryltetralones in high yields through a one-pot, BBr3-promoted O-demethylation and cyclization sequence. The key α-aryltetralone intermediates were obtained by direct α-arylation of tetralones with o-alkoxybromoarenes in the presence of Pd2(dba)3 (2.5 mol-%) and tBu3PHBF4 (10 mol-%) as catalysts, together with 2.5 equiv. of KOH in dioxane/H2O (4:1), under microwave irradiation conditions (80 W, 100 °C, 40 min), leading to α-monoaryltetralones in good yields.

LA NATURALEZA DEL DESASTRE: UNA REFLEXIÓN CONTEMPORÁNEA DEL CONCEPTO Y SUS IMPLICACIONES

Donde hay la mirada humana hay desastre. Éste no ocurre ajeno ni al margen del ser, ni es inherente a la dinámica de la esfera de la naturaleza. Más aún, es el resultado de una práctica contextualizada históricamente en un tiempo donde los trastornos se han agudizado por la lógica asimétrica del capital. El desastre no es natural. Vinculado en principio al devenir de la naturaleza, se alza hoy como categoría que permite el usufructo de los nuevos agentes hegemónicos y los nuevos métodos de control político, mediante el manejo pernicioso de las crisis como condición inexorable de una sociedad que ha sido educada y condenada a aceptar su vulnerabilidad. La presente ponencia, desde una perspectiva crítica, pretende abordar el tema de la caracterización de los desastres en el contexto de un mundo dominado por la esfera del capital, en cuyo marco ha manejado ideológicamente un discurso que apela a las crisis y la vulnerabilidad como situaciones inherentes a la naturaleza, soslayando su carácter social, al tiempo que los nuevos agentes hegemónicos apuntalan sus nuevos métodos de control a escala global, generando impactos de orden espacial. La intención es contribuir a la discusión del concepto desastre desde la perspectiva social y sus implicaciones de tipo espacial.