The potential of carbonyl-stabilized phosphonium ylides as ligands for novel catalysis was explored. We found that the combination of phosphonium ylides and metal halide salts efficiently catalyzed the reaction of epoxides with carbon dioxide under mild conditions. Five-membered cyclic carbonates, including disubstituted cyclic carbonates, were obtained in good yields with the use of 1 atm of carbon dioxide at 35 °C. Terminal epoxides could be converted to -aryl oxazolidinones in the reaction with isocyanates under a similar catalytic system.
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http://dx.doi.org/10.1021/acs.joc.0c01101 | DOI Listing |
JMIR Res Protoc
January 2025
McMaster University, Hamilton, ON, Canada.
Background: Research has shown that engaging in a range of healthy lifestyles or behavioral factors can help reduce the risk of developing dementia. Improved knowledge of modifiable risk factors for dementia may help engage people to reduce their risk, with beneficial impacts on individual and public health. Moreover, many guidelines emphasize the importance of providing education and web-based resources for dementia prevention.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Molecular Synthesis Center, Key Laboratory of Marine Drugs of Ministry of Education, Shandong Key Laboratory of Glycoscience and Glycotherapeutics, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China.
2-Deoxy-β-glycosides are essential components of natural products and pharmaceuticals; however, the corresponding 2-deoxy-β-glycosidic bonds are challenging to chemically construct. Herein, we describe an efficient catalytic protocol for synthesizing 2-deoxy-β-glycosides via either IPrAuNTf-catalyzed activation of a unique 1,2--positioned C2--propargyl xanthate (OSPX) leaving group or (PhO)PAuNTf-catalyzed activation of a 1,2--C2--alkynylbenzoate (OABz) substituent of the corresponding thioglycosides. These activation processes trigger 1,2-alkyl/arylthio-migration glycosylation, enabling the synthesis of structurally diverse 2-deoxy-β-glycosides under mild reaction conditions.
View Article and Find Full Text PDFBlood
January 2025
New York Blood Center, New York, New York, United States.
Babesiosis in sickle cell disease (SCD) is marked by severe anemia but the underlying red blood cell (RBC) rheological parameters remain largely undefined. Here, we describe altered RBC deformability from both primary (host RBC sickle hemoglobin mediated) and secondary changes (Babesia parasite infection mediated) to the RBC membrane using wild type AA, sickle trait AS and sickle SS RBCs. Our ektacytometry (LORRCA) analysis demonstrates that the changes in the host RBC bio-mechanical properties, pre- and post- Babesia infection, reside on a spectrum of severity, with wild type infected AA cells, despite showing a significant reduction of deformability under both shear and osmolarity gradients, exhibiting only a mild phenotype; compared to infected AS RBCs which show median changes in deformability and infected SS RBCs which exhibit the most dramatic impact of infection on cellular rheology, including an increase in Point of Sickling values.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States.
Enthalpy is often the focal point when designing monomers for polymer circularity, but much less is explored on how entropy can be exploited to create polymers with synergistic circularity and properties. Here, we design a series of spiro-lactones (SLs) with closed-chain cycloalk(en)yl substituents at the α,α-position of δ-valerolactone (δVL), which, when combined with the parent δVL and -α,α-dialkyl-substituted δVL with open-chain alkyl groups, provide a desired platform for exploring the circular polymer design by focusing on the entropy change of polymerization. These SLs exhibit finely balanced (de)polymerizability that is regulated chiefly by entropy differentiation, allowing both the facile synthesis of polyester PSLs ( up to 1000 kg mol) in a living fashion and selective depolymerization of the PSLs to completely recover monomers under mild conditions (using a recyclable catalyst at 100 °C).
View Article and Find Full Text PDFVet Med Sci
March 2025
Department of Veterinary Medicine, National Chiayi University, Chiayi City, Taiwan.
This case report highlights a potential vaccine safety concern associated with the Pseudorabies virus (PRV) live vaccine, which warrants further investigation for comprehensive understanding. Vaccine-induced immune thrombotic thrombocytopenia (VITT), a novel syndrome of adverse events following adenovirus vector COVID-19 vaccines, was observed after vaccination with Zoetis PR-VAC PLUS. This led to a 100% morbidity and high mortality among PRV-free Danish purebred pigs from Danish Genetics Co.
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