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A general and efficient synthesis of α-haloglycine esters from commercially available feedstock chemicals, in a single step, is reported. The reactivity of these α-haloglycine esters with various nucleophiles was studied as surrogates of α-iminoesters upon activation with hydrogen-bond donor catalysts. DFT calculations on the α-haloglycine structures (X = F, Cl, Br) accompanied by an X-ray characterization of the α-bromoglycine ester support the existence of a "generalized" anomeric effect created by hyperconjugation. This peculiar hyperconjugative effect is proposed to be responsible for the enhanced halogen nucleofugality leading to a facile halogen abstraction by hydrogen-bond donor catalysts. This reactivity was exploited with thiourea catalysts on several catalytic transformations (aza-Friedel-Crafts and Mannich reactions) for the synthesis of several types of non-proteinogenic α-amino esters.
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http://dx.doi.org/10.1002/ejoc.201901033 | DOI Listing |
Org Lett
September 2025
Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405-7102, United States.
This communication describes a straightforward method for the trifluoromethylborylation of unactivated alkenes. The reaction proceeds through the formation of an electron donor-acceptor (EDA) complex between a trifluoromethylthiophenium salt and bis(catechol)diboron under broad-spectrum white-light irradiation. Due to the mild reaction conditions, the trifluoromethylborylation tolerates a wide range of functional groups, including esters, acids, alcohols, epoxides, and a variety of heterocycles.
View Article and Find Full Text PDFFEMS Yeast Res
September 2025
Enology and Fermentation Biotechnology Area, Department of Science and Food Technology. Faculty of Chemistry, Universidad de la Republica. Montevideo, Uruguay.
Hanseniaspora species are among the most prevalent yeasts found on grapes and other fruits, with a growing role in wine fermentation due to their distinctive metabolic profiles. This review focuses on the functional divergence within the genus, particularly between the fast-evolving fruit clade and the slow-evolving fermentation clade. While species in the fruit clade often exhibit limited fermentation capacity with interesting enzymatic activity, members of the fermentation clade-especially H.
View Article and Find Full Text PDFOrg Biomol Chem
September 2025
Division of Chemistry and Chemical Engineering, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, UK.
In an attempt to react aminocyclopropenones with cyclic imines in order to synthesise amido-substituted pyrrolizidine natural products, we found that aminocyclopropenones undergo a previously unreported stereospecific and regiospecific catalyst-free, thermal ring-opening reaction with alcohols to yield β-enamino esters (also known as vinylogous carbamates or aminoacrylates). We report 21 examples in 45 to 97% isolated yield. The reaction occurs nucleophilic attack at the cyclopropenone carbonyl followed by regiospecific ring opening of the cyclopropenone with retention of alkene geometry.
View Article and Find Full Text PDFChemSusChem
September 2025
Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, WI 53706, USA.
Spent liquors of biomass pretreatment provide a source for renewable chemical production. These liquors require treatment before being discharged; otherwise, they negatively impact the environment. Herein, spent liquors from aqueous ammonia pretreatment of poplar wood are characterized for phenolic content via liquid chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy.
View Article and Find Full Text PDFRSC Adv
September 2025
Food and Drug Safety Research Center, Pharmaceutical Sciences Institute, Tabriz University of Medical Sciences Tabriz Iran.
This study focuses on developing an analytical method to efficiently extract and concentrate several adipate and phthalate plasticizers that can migrate from plastic packaging into various wound disinfectants. The study employed an approach that combined dispersive micro solid phase extraction with dispersive liquid-liquid microextraction using ZIF-4 as an adsorbent. The adsorbent was thoroughly characterized to understand its properties.
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