Effect of intramolecular Paternò-Büchi reaction on the thermodynamics and kinetics of nearly degenerate [3,3]-sigmatropic shift in fluxional polycycles. | LitMetric
Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado 80208, USA.
Published: May 2009
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Article Abstract
In reactions with weak dienophiles, cyclooctatetraene (COT) often yields 2:1 adducts possessing the fluxional bicyclo[5.1.0]octadiene moiety. They undergo fast, nearly degenerate Cope rearrangement with an activation barrier similar to that of the parent dihydrobullvalene. Irradiation to excite the carbonyl moiety induces an intramolecular Paterno-Buchi cyclization yielding endo-oxetanes and significantly changing the Cope-averaged NMR spectra. In this paper we examine the effect of skeletal distortion caused by intramolecular [2 + 2]-photoaddition on thermodynamics and the activation barrier of the [3,3]-sigmatropic tautomerism. Our finding is that such a distortion lifts the energetic degeneracy of the two valence tautomers, while not affecting the activation barrier.
Background: Chemotherapy-induced mucositis (CIM) significantly impacts quality of life and reduces survival in patients treated with specific chemotherapeutic agents. However, effective clinical treatments for CIM remain limited. Intravenous immunoglobulin (IVIg), a therapeutic derived from pooled human plasma, is widely used to treat inflammatory diseases.
Northeast Normal University, Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education, Institute of Functional Material Chemistry, Local United Engineering Lab for Power Battery, CHINA.
Construction of metal-organic cages (MOCs) with internal modifications is a promising avenue to build enzyme-like cavities and unlocking the mystery of highly catalytic activity and selectivity of enzymes. However, current interests are mainly focused on single-metal-node cages, little achievement has been expended to metalloclusters-based architectures, and the in situ endogenous generation of metal clusters. Herein, based on the hard-soft-acids-bases (HSAB), the metalloclusters-based heterometallic MOC (Cu3VMOP) constructed of [Cu3OPz3]+ and [V6O6(OCH3)9(SO4)(CO2)3]2- clusters was obtained by one-pot method.
Direct cardiac reprogramming of fibroblasts into induced cardiomyocytes (iCMs) can be achieved by ectopic expression of cardiac transcription factors (TFs) via viral vectors. However, risks like genomic mutations, viral toxicity, and immune response limited its clinical application. Transactivation of endogenous TFs emerges as an alternative approach that may partially mitigate some of the risks.
Background: Nephrotic syndrome has a significant impact on global health, often leading to cardiovascular disease and high mortality due to limited effective treatments. This study investigates the efficacy of Shensu IV in a puromycin aminonucleoside (PAN)-induced rat model of nephropathy.
Methods: Rat models and podocyte PAN nephropathy models were established with PAN and treated with Shensu IV.
Background: Sheep scab, caused by the highly infectious mite, is considered to be endemic in Northern Ireland, although little investigation has been reported. A pilot project was undertaken to engage farmers, confirm cases with diagnostic methods and identify specific barriers to control, with the aim of informing future control programmes.
Methods: Through farmers self-reporting suspected outbreaks, on-farm risk assessments and clinical investigations were carried out by the farm's veterinary surgeon, who utilised light microscopy and serological testing to diagnose scab.
