Diazo compounds and their precursors represent an interesting chemical category for organic synthesis. Particularly, -tosylhydrazones have attracted attention for their easy accessibility and diverse reactivity, including carbene transfer reactions. We described a visible light-induced N-H insertion reaction of anilines on -generated diazo compounds.
View Article and Find Full Text PDFResearch on synthesizing nitrogen-containing heterocyclic scaffolds is important because these structures are commonly found in Nature, such as in the alkaloids' family. In our study, we propose a new method to synthesize the isoquinoline core using an electron donor-acceptor (EDA) complex strategy. Our mechanistic investigations have confirmed that our synthesis process operates through an EDA mechanism, which is not extensively discussed in the literature, particularly regarding its applications on alkynyl substrates.
View Article and Find Full Text PDFVisible-light catalysis is now widely acknowledged as a potent approach for efficiently constructing various types of frameworks, particularly bioactive compounds, with high yields. However, there is still a strong need for further advancements in these methods because certain delicate compounds cannot be synthesized due to structural sensitivity. In this context, a seamless reaction pathway toward 6-membered ring nitrogen-containing heterocycles is presented here, offering access to isoquinoline derivatives and related heterocycles.
View Article and Find Full Text PDFThis symposium is the third PSL (Paris Sciences & Lettres) Chemical Biology meeting (2016, 2019, 2023) held at Institut Curie. This initiative originally started at Institut de Chimie des Substances Naturelles (ICSN) in Gif-sur-Yvette (2013, 2014), under the directorship of Professor Max Malacria, with a strong focus on chemistry. It was then continued at the Institut Curie (2015) covering a larger scope, before becoming the official PSL Chemical Biology meeting.
View Article and Find Full Text PDF-Containing heterocycles are important scaffolds due to their ubiquitous presence in bioactive compounds. Their synthesis has been considered as an important research field. In this work we report the access to 6- and 7-membered rings a photoinduced strategy.
View Article and Find Full Text PDFNew polycyclic heterocycles were synthesised and evaluated as potential inhibitors of thymidine phosphorylase (TP). Inspired by the pharmacophoric pyrimidinedione core of the natural substrate, four series have been designed in order to interact with large empty pockets of the active site: pyrimidoquinoline-2,4-diones (series A), pyrimidinedione linked to a pyrroloquinoline-1,3-diones (series B and C), the polycyclic heterocycle has been replaced by a pyrimidopyridopyrrolidinetetraone (series D). In each series, the tricyclic nitrogen heterocyclic moiety has been synthesised by a one-pot multicomponent reaction.
View Article and Find Full Text PDFRearrangement reactions in organic chemistry are attractive strategies to build efficiently complex scaffolds, in just one step, from simple starting materials. Among them, aryl migrations are certainly one of the most useful and straightforward rearrangement for building attractive carbon-carbon bonds. Of note, anionic aryl migration reactions have been largely described compared to their radical counterparts.
View Article and Find Full Text PDFAn efficient silver-catalyzed tandem reaction for the formation of 1,2-dihydroisoquinoline derivatives is herein reported. Highly functionalized multiheterocyclic scaffolds are accessible in a straightforward manner using readily accessible starting materials under mild conditions. This methodology offers an attractive route for the synthesis and development of a biologically relevant new heterocyclic pharmacophore, merging the biological activities of isoquinolines with those of various nitrogen-containing heterocycles (indoles, pyrroles) incorporated during the tandem reaction.
View Article and Find Full Text PDFRearrangement reactions are certainly one of the most useful approaches towards complex structures in organic chemistry. With efficient conditions, it is indeed possible to convert simple substrates into highly functionalized products. Moreover, combining this approach with an attractive initiation process, such as visible-light catalysis, makes these reactions particularly powerful.
View Article and Find Full Text PDFBackground: Best practices in breastfeeding are often not followed despite appropriate levels of knowledge and positive attitudes regarding the benefits of human milk. For many reasons, some women do not initiate breastfeeding, suspend breastfeeding early, or initiate complementary feeding earlier than recommended. Usual measurement methods use large sample surveys at a national scale, which are not well suited for monitoring sub-national differences.
View Article and Find Full Text PDFWe report herein the synthesis of a newly described anti-cancer agent, NRPa-308. This compound antagonizes Neuropilin-1, a multi-partners transmembrane receptor overexpressed in numerous tumors, and thereby validated as promising target in oncology. The preparation of NRPa-308 proved challenging because of the orthogonality of the amide and sulphonamide bonds formation.
View Article and Find Full Text PDFObjective: To describe and quantify the magnitude and distribution of stunting, wasting, anaemia, overweight and obesity by wealth, level of education and ethnicity in Ecuador.
Design: We used nationally representative data from the 2012 Ecuadorian National Health and Nutrition Survey. We used the Multidimensional Poverty Index (MPI) as a proxy of wealth.
Visible light catalysis allows the regioselective synthesis of oxazolines in high yields. The mild photosensitized manifold leverages the intermolecular formation of oxazolines with a wide functional group tolerance on both benzoyl azides and alkenes partners. Mechanistic investigations suggest the sensitization of the azide moiety as the key activation step.
View Article and Find Full Text PDFThe synthesis and characterization of original NHC ligands based on an imidazo[1,5-a]pyridin-3-ylidene (IPy) scaffold functionalized with a flanking barbituric heterocycle is described as well as their use as tunable ligands for efficient gold-catalyzed C-N, C-O, and C-C bond formations. High activity, regio-, chemo-, and stereoselectivities are obtained for hydroelementation and domino processes, underlining the excellent performance (TONs and TOFs) of these IPy-based ligands in gold catalysis. The gold-catalyzed domino reactions of 1,6-enynes give rise to functionalized heterocycles in excellent isolated yields under mild conditions.
View Article and Find Full Text PDFChemical Biology is the science of designing chemical tools to dissect and manipulate biology at different scales. It provides the fertile ground from which to address important problems of our society, such as human health and environment.
View Article and Find Full Text PDFBackground: In order to understand why rates of overweight and obesity are so high in the Ecuadorian province of Galapagos, this study analyzes changes in household food expenditures and perceptions and practices related to food consumption patterns. Galapagos is understood as an unusual but not unique case because conditions there graphically illustrate trends observed in communities and countries worldwide. A mixed methods approach was employed: a quantitative component was based on expenditures for foods classified according to the NOVA system, and a qualitative component utilized focus group discussions, key informant interviews, and structured observations.
View Article and Find Full Text PDFBackground:: The simultaneous presence of undernutrition and over-nutrition represents a paradox in global public health and is of increasing concern in Ecuador, where chronic malnutrition and overweight and obesity occur in the context of demographic and epidemiologic transitions. Two overlapping trends are present in Ecuador; while levels of stunting have decreased slowly in the past three decades, increasing proportions of children <5 years and women of reproductive age suffer from overweight and obesity.
Aim:: To analyze stunting and overweight and obesity in children <5 and their mothers aged from 15 to 49 years in the context of demographic and household characteristics between 1986 and 2012.
A silver-catalyzed cycloisomerization reaction of a series of o-alkynylbenzohydroxamic acids is reported. Several 5-exo-dig and 6-endo-dig modes of cyclization were observed with the nitrogen or oxygen atoms of the amide group acting as nucleophiles. The selectivity was strongly dependent on the silver salt used and on the presence of triphenylphosphine as an additive.
View Article and Find Full Text PDFWe report the synthesis of various phthalazines a new cascade reaction, initiated by visible light photocatalysis, involving a radical hydroamination reaction followed by a radical Smiles rearrangement. Phthalazine derivatives are obtained in high yields and from a broad scope readily accessible -alkynylsulfonohydrazone precursors. The mild photoredox conditions ensure an excellent functional group tolerance.
View Article and Find Full Text PDFA mild and general method for the direct alkynylation of azoles such as pyrrole, indole, and 7-azaindole is described here. Using a simple catalytic system such as Pd(OAc)2 (2.5 mol %), P(tBu)2Me·HBF4 (5 mol %), and NaOAc (2 equiv) allowed the regioselective introduction of various alkynyl residues at the C-2 position of pyrroles.
View Article and Find Full Text PDFBackground: Ecuador's current nutrition policies have not taken adequate notice of the double burden of malnutrition and continue to focus on stunting and to a lesser extent on overweight, without addressing the simultaneous presence of undernutrition, micronutrient deficiencies, and overweight or obesity (OW/OB).
Objective: The aim of this article was to describe the prevalence and distribution of undernutrition (stunting, anemia, and zinc deficiency), overweight, and obesity in Ecuador to explore the evolving double burden of malnutrition at the national, household, and individual levels and to discuss whether current public health policies are addressing the double burden.
Design: Data from the 2012 Ecuadorian National Health and Nutrition Survey (ENSANUT-ECU) was used to estimate the dual burden of malnutrition at the national, household, and individual levels in children <5 y old, school-aged children, and women of reproductive age.
In the early 2000s, the anticancer drug imatinib (Glivec®) appeared on the market, exhibiting a new mode of action by selective kinase inhibition. Consequently, kinases became a validated therapeutic target, paving the way for further developments. Although these kinases have been thoroughly studied, none of the compounds commercialized since then target cyclin-dependent kinases (CDKs).
View Article and Find Full Text PDFA Ag-catalyzed versatile and efficient access to 1H,1-arylisochromenes is reported. Starting from ortho-alkynylbenzaldehydes bearing various substitution patterns on the benzaldehyde and alkynyl units, the use of silver triflate (10 mol %) allowed a domino hydroarylation/cycloisomerization reaction process, leading to aryl-functionalized 1H-isochromene (>10 compounds, 80-98% yields). Notably, the reaction conditions were also compatible with benzaldehydes bearing an aliphatic-substituted alkynyl moiety with modest to good yields (34-88%, 10 compounds).
View Article and Find Full Text PDFA family of furoquinolines were efficiently obtained through a tandem acetalization/cycloisomerization process catalyzed by (5 mol%) silver imidazolate polymer and triphenylphosphine, and diversity was brought by the use of 7 different alcohol groups. From these furoquinolines, 3 examples of reduced derivatives could be obtained (d.r.
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