Unlike other metal fluorides, catalytic titanium tetrafluoride enhances the direct amidation of aromatic and aliphatic carboxylic acids and -protected amino acids in refluxing toluene. While aromatic acids were converted to amides with 10 mol% of the catalyst within 24 h, aliphatic acids underwent a faster reaction (12 h), with lower catalyst loading (5 mol%). This protocol is equally efficient with alkyl and aryl amines providing a variety of carboxamides and peptides in 60-99% yields.
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http://dx.doi.org/10.1039/d3ob01943h | DOI Listing |
Rev Alerg Mex
December 2024
Jefe del servicio de Alergia, Hospital Central del Instituto de Previsión Social (IPS), Paraguay.
Objective: To develop a treatment algorithm for patients with penicillin allergy.
Methods: Retrospective study, carried out in adult patients with penicillin allergy, who were in group 3 or 4 of the established classification, and attended the outpatient clinic of the Department of Pulmonology and Allergy of the Central Hospital of the Social Security Institute, between January 2021 and December 2022. Each patient underwent an amoxicillin provocation test, after obtaining informed consent.
Nat Commun
January 2025
State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, China.
Nat Commun
January 2025
Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA.
Complementary methods toward the selective functionalization of indole and oxindole frameworks employing an alternative strategy in heteroaryl C-H functionalizations are presented herein. This work focuses on a catalyst-controlled, site selective C-H activation/functionalization of 3-acyl indoles, wherein an amide serves as a robust and versatile directing group capable of undergoing concomitant 1,2-acyl translocation/C-H functionalization in the presence of a Rh/Ag co-catalysts to provide the cross-coupled adducts in high yields. In contrast, the use of Ir/Ag catalysts subverted the 1,2-acyl migration to afford the corresponding C2-functionalized products in good to excellent yields.
View Article and Find Full Text PDFOrg Lett
January 2025
Laboratory of Catalysis and Organic Synthesis, Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247667, Uttarakhand, India.
Herein, we have reported the application of bench stable perfluoroalkanoic acids as fluoro-alkylating reagents in combination with DIB and primary amides for sequential one-pot transformation to R-embedded functionalized amides under metal-free conditions. The protocol is tolerant to a range of sensitive functional groups (>33 examples and up to 90% yield), and perfluoro acids. Preliminary mechanistic studies, control experiments, in situ F-NMR analyses, and the synthesis of intermediate species were performed to understand the reaction pathways.
View Article and Find Full Text PDFSci Rep
December 2024
Laboratory of Bioinorganic Chemistry, Department of Pharmacy and Biotechnology, University of Bologna, 40127, Bologna, Italy.
This manuscript details the application of Isothermal Titration Calorimetry (ITC) to characterize the kinetics of 3CL, the main protease from the Severe Acute Respiratory Syndrome CoronaVirus-2 (SARS-CoV-2), and its inhibition by Ensitrelvir, a known non-covalent inhibitor. 3CL is essential for producing the proteins necessary for viral infection, which led to the COVID-19 pandemic. The ITC-based assay provided rapid and reliable measurements of 3CL activity, allowing for the direct derivation of the kinetic enzymatic constants K and k by monitoring the thermal power required to maintain a constant temperature as the substrate is consumed.
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