An unprecedented -heterocyclic carbene (NHC)-catalyzed enantioselective [3 + 2] annulation of enals with vinyl ketones has been achieved. Unlike chalcones, the β-unsubstituted enones, namely, vinyl ketones, have remained challenging in terms of reactivity, especially enantioselectivity. The disubstituted cyclopentenes were obtained in good yields and excellent stereoselectivities in the presence of Ti(OPr).
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http://dx.doi.org/10.1021/acs.joc.2c01894 | DOI Listing |
Front Chem
December 2024
Department of Chemistry, University of Lucknow, Lucknow, India.
Rhodium(III) catalysis has been used for C-H activation of -nitrosoanilines with substituted allyl alcohols. This method provides an efficient synthesis of the functional -nitroso β-aryl aldehydes and ketones with low catalyst loading, high functional group tolerance, and superior reactivity of allyl alcohols toward -nitrosoanilines. We demonstrated that reaction also proceeds through the one-pot synthesis of -nitrosoaniline, followed by subsequent, C-H activation.
View Article and Find Full Text PDFEur J Med Chem
December 2024
A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, ul. Vavilova 28, bld. 1, Moscow, 119334, Russia. Electronic address:
Thevinols and their 3-O-demethylated relatives, orvinols, are derivatives of the Diels-Alder adduct of natural alkaloid thebaine with methyl vinyl ketone. Taken together, thevinols and orvinols constitute an important family of opioid receptor (OR) ligands playing an important role in both the OR mediated antinociception and OR antagonism. Herein, we disclose for the first time the antagonist activity of the N-allyl substituted orvinol derivative fluorinated within the pharmacophore associated with C(20) and its surrounding.
View Article and Find Full Text PDFMolecules
December 2024
Friedrich-Alexander-Universität Erlangen-Nürnberg, Department of Biology, Pharmaceutical Biology, Staudtstraße 5, 91058 Erlangen, Germany.
Enzymes capable of processing a variety of compounds enable plants to adapt to diverse environmental conditions. PRISEs (progesterone-5β-reductase/iridoid synthase-like enzymes), examples of such substrate-promiscuous enzymes, are involved in iridoid and cardenolide pathways and demonstrate notable substrate promiscuity by reducing the activated C=C double bonds of plant-borne and exogenous 1,4-enones. In this study, we identified PRISE genes in () and (), and the corresponding enzymes were determined to share a sequence identity of 95%.
View Article and Find Full Text PDFEnviron Pollut
December 2024
Guangdong Key Laboratory of Environmental Pollution and Health, Center for Environmental Microplastics Studies, School of Environment, Jinan University, Guangzhou 511443, China; Key Laboratory of Philosophy and Social Science in Guangdong Province of Community of Life for Man and Nature, Jinan University, Guangzhou 511443, China. Electronic address:
Baby play mats serve as essential protective equipment widely utilized in residences, daycares, and kindergartens. Given their direct contact with infants and young children, the pollutants released from play mats may pose potential health risks. This study investigated the impact of disinfection on the release of microplastics (MPs) from play mats and offers an in-depth analysis of the derived volatile organic compounds (VOCs) release.
View Article and Find Full Text PDFJ Org Chem
December 2024
Department of Chemistry, Sidho-Kanho-Birsha University, Purulia 723104, W.B., India.
Distinctive, green, innovative, and well-organized photoinduced (metal- or photocatalyst-free) regioselective decarbonylative and decarboxylative C-O bond functionalization protocols to access aryl 2-aminobenzoates and 2-substituted benzoxazinone derivatives in excellent yields have been devised. These are achieved through the chemoselective scission of isatoic anhydride with ketones, diaryliodonium triflate, nitroalkene, phthalazinone, and phenol derivatives, which, in turn, served as the representative "electrophilic and nucleophilic" coupling partners. Control experiments and DFT calculations reveal that electrophilic radical-bearing coupling partners specifically follow the decarbonylation pathway, while nucleophilic radical-bearing conjugates facilitate the decarboxylation process.
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