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El uso del agua en las poblaciones de México para las actividades domésticas, de traspatio y agropecuarias demanda formas modernas de gobierno según las circunstancias de cada una. Por ello, en este estudio se analiza a los asentamientos de Yashanal y Tzajalchen, en el municipio de Tenejapa, Chiapas, respecto a su gestión del recurso procedente del manantial situado en el territorio de Yashana, sagrado para los antepasados mayas y de aprovechamiento comunitario actual, concretada con acuerdos que resulten en una estructura viable para los beneficiarios. Según se nota, las diferencias bloquean la distribución del elemento. Se trata al agua como bien público mediante los conceptos de gobernanza, gobernanza comunitaria, actores y gestión, comparando cómo se le gestiona en los dos asentamientos para evaluar la eficiencia en el establecimiento de normas. Se analizan las pugnas entre localidades, observando el comportamiento de los actores públicos y privados, para quienes decidir se complica debido a que no han establecido reglas de interacción por cambios culturales y organizacionales.

The major source of fluoride, namely calcium difluoride (CaF 2 ), is derived from the mineral fluorspar. Recent advances in the activation of CaF 2 via mechanochemical methods have inspired investigation of the fundamental properties of Ca-F bonds in molecular complexes. However, the paucity of well-defined molecular Ca-F-containing complexes undermines systematic understanding of the factors governing nucleophilic fluoride delivery. Here we report the use of a multidentate bis(phenoxide) ligand based on a 1,4,7-triazacyclononane (TACN) scaffold for the formation of well-defined Ca-F complexes and demonstrate their capabilities in fluoride delivery. Key to this synthesis is a desymmetrization step carried out on the TACN ligand within the Ca coordination sphere. A series of stable anionic dinuclear calcium fluoride complexes has then been accessed and characterized by NMR spectroscopy (critically by 19 F NMR) and X-ray crystallography. Nucleophilic fluoride delivery can be used to generate C-F, Si-F and S-F bonds, with a notable advance over amide-derived ligand scaffolds being the reduced extent of side reactions derived from competing attack on the electrophile by the less nucleophilic O-donor anionic ligand set., (© 2024 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

An asymmetric 1,2-dicarbofunctionalization of unactivated alkenes with aryl iodides and aryl/alkenylboronic esters under nickel/bioxazoline catalysis is disclosed. A wide array of aryl and alkenyl nucleophiles are tolerated, furnishing the products in good yield and with high enantioselectivity. In addition to terminal alkenes, 1,2-disubstituted internal alkenes participate in the reaction, establishing two contiguous stereocenters with high diastereoselectivity and moderate enantioselectivity. A combination of experimental and computational techniques shed light on the mechanism of the catalytic transformation, pointing to a closed-shell pathway with an enantiodetermining migratory insertion step, where stereoinduction arises from synergistic interactions between the sterically bulky achiral sulfonamide directing group and the hemilabile bidentate ligand.