The synthetic scope and utility of Pd-catalyzed aerobic oxidation reactions has advanced significantly over the past decade, and these reactions have potential to address important green-chemistry challenges in the pharmaceutical industry. This potential has been unrealized, however, because safety concerns and process constraints hinder large-scale applications of this chemistry. These limitations are addressed by the development of a continuous-flow tube reactor, which has been demonstrated on several scales in the aerobic oxidation of alcohols. Use of a dilute oxygen gas source (8% O(2) in N(2)) ensures that the oxygen/organic mixture never enters the explosive regime, and efficient gas-liquid mixing in the reactor minimizes decomposition of the homogeneous catalyst into inactive Pd metal. These results provide the basis for large-scale implementation of palladium-catalyzed (and other) aerobic oxidation reactions for pharmaceutical synthesis.
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http://dx.doi.org/10.1039/c0gc00106f | DOI Listing |
Chemistry
January 2025
Shihezi University, School of Chemistry and Chemical Engineering/State Key Laboratory Incubation Base for Green Processing of Chemical Engineering, North 4th Road, 832003, Shihezi, CHINA.
An N,N,N-type Cu(Ⅱ) complex-catalyzed desaturation method for converting alcohols, ketones, lactones, and lactams to their α,β-unsaturated carbonyl compounds is reported. The dehydrogenation reaction can be conducted with a green terminal oxidant O2 without requiring strong acid/base or stoichiometric oxidants. The Cu(Ⅱ) complex/TEMPO/O2 system uses a non-noble catalyst, and a green terminal oxidant as well as demonstrates high activity and functional group tolerance.
View Article and Find Full Text PDFJ Transl Med
January 2025
Department of Orthopedics, Affiliated Hospital of Nanjing University of Chinese Medicine / Jiangsu Province Hospital of Chinese Medicine, Nanjing, Jiangsu, 210029, China.
Background: Skeletal muscle injury caused by excessive exercise is one of the most commonly seen clinical diseases. It is indispensable to explore drugs for treating and relieving skeletal muscle injury. Gallic acid (GA) is a polyphenolic extract that has anti-inflammatory and antioxidant biological activities.
View Article and Find Full Text PDFNature
January 2025
Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA.
The low reduction potentials required for the reduction of dinitrogen (N) render metal-based nitrogen-fixation catalysts vulnerable to irreversible damage by dioxygen (O). Such O sensitivity represents a major conundrum for the enzyme nitrogenase, as a large fraction of nitrogen-fixing organisms are either obligate aerobes or closely associated with O-respiring organisms to support the high energy demand of catalytic N reduction. To counter O damage to nitrogenase, diazotrophs use O scavengers, exploit compartmentalization or maintain high respiration rates to minimize intracellular O concentrations.
View Article and Find Full Text PDFJ Adv Res
January 2025
Department of Rehabilitation Medicine, the First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen 361003, China. Electronic address:
Objective: The aim of this study was to investigate the potential molecular mechanisms by which taurine protects against cartilage degeneration.
Methods: The anterior cruciate ligament transection (ACLT) surgery was used to construct an animal model of osteoarthritis (OA). Metabolomics was used to identify characteristic metabolites in osteoarthritic chondrocytes.
Biochim Biophys Acta Bioenerg
January 2025
Laboratoire de Bioélectrochimie et Spectroscopie, UMR 7140, Chimie de la Matière Complexe, Université de Strasbourg-CNRS 4, Rue Blaise Pascal, 67081 Strasbourg, France; Institut universitaire de France (IUF), France. Electronic address:
The reduction of oxygen to water is crucial to life under aerobic conditions. Cytochrome bd oxidases perform this reaction with a very high oxygen affinity. Members of this protein family are solely found in prokaryotes and some archaea playing an important role in bacterial virulence and antibiotic resistance.
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