Results 91 to 100 of about 182,970 (169)
ChemSusChem, Volume 19, Issue 14, 29 July 2026.A green, metal‐free catalytic system based on a deep eutectic solvent‐type mixture of tetrabutylammonium iodide and levulinic acid enables the solvent‐free cycloaddition of carbon dioxide (CO2) to epoxides. Cooperative acid–nucleophile activation affords cyclic carbonates in up to 95% yield at atmospheric pressure using only 1.4 mol% of catalyst.
Tatiana Martí +5 more
wiley +1 more source
Bioactive Secondary Metabolites from Phomopsis sp., an Endophytic Fungus from Senna spectabilis
Molecules, 2014 Chemical investigation of an acetonitrile fraction from the endophytic fungus Phomopsis sp. led to the isolation of the new natural product 2-hydroxy-alternariol (7) together with the known compounds cytochalasins J (1) and H (2), 5'-epialtenuene (3) and
Vanessa Mara Chapla +10 more
doaj +1 more source
Aplicativos para o ensino e aprendizagem de Química Orgânica
, 2018 Tecnologias moveis e sem fio (TMSF), em especial tablets e smartphones, estao alterando nossa relacao com a informacao e a forma de produzir conhecimento.
A. Nichele, Letícia Zielinski do Canto
semanticscholar +1 more source
Beilstein Journal of Organic Chemistry, 2017 This work describes a new approach to obtain new β-vinylporphyrin derivatives through palladium-catalyzed cross-coupling reaction of 2-bromo-5,10,15,20-tetraphenylporphyrinatozinc(II) with N-tosylhydrazones.
Vinicius R. Campos +5 more
doaj +1 more source
O uso da ludicidade como ferramenta para o ensino de química orgânica: o que pensam os alunos
, 2017 Para a maioria dos alunos a disciplina de quimica e muito teorica, monotona, com muitos calculos e, na maioria das vezes, nao possui interacao com seu cotidiano.
Elaine da Silva Ramos +2 more
semanticscholar +1 more source
, 2017 Desde diferentes espacios se ha manifestado que la formacion en competencias pareceria ser el desafio de la Educacion Superior. En este modelo de ensenanza no solo es importante la comprension del contenido conceptual de las disciplinas, sino tambien la ...
L. Viera, S. Ramírez, A. Fleisner
semanticscholar +1 more source
Carboxyxanthones: Bioactive Agents and Molecular Scaffold for Synthesis of Analogues and Derivatives
Molecules, 2019 Xanthones represent a structurally diverse group of compounds with a broad range of biological and pharmacological activities, depending on the nature and position of various substituents in the dibenzo-γ-pyrone scaffold.
João Ribeiro +4 more
doaj +1 more source
Educación QuímicaThis work presents a didactic sequence (DS) for teaching key laboratory techniques—continuous and discontinuous extraction, vacuum and atmospheric distillation, steam extraction, and thin-layer chromatography (TLC)—to first-year organic chemistry ...
Brenda de Moraes Cordeiro +1 more
doaj +1 more source
HPW-Catalyzed environmentally benign approach to imidazo[1,2-a]pyridines
Beilstein Journal of Organic ChemistryThe imidazo[1,2-a]pyridine moiety is present in drugs with several biological activities. The most direct way of obtaining this nucleus is the Groebke–Blackburn–Bienaymé three-component reaction (GBB-3CR) between aminopyridines, aldehydes, and ...
Luan A. Martinho +1 more
doaj +1 more source
Educación Química, 2018 Escribimos esta carta con el fin de señalar algunas imprecisiones y de hacer algunos agregados al artículo sobre mecanismos de reacción en la Química Orgánica aparecido en el Vol. 23, Núm. 2, pp. 205-207, 2012 de Educación Química.
Rosa María Aguilar-Garduño +2 more
doaj +1 more source