49 research outputs found

    Rapid access to polycyclic N-heteroarenes from unactivated, simple azines via a base-promoted Minisci-type annulation

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    Conventional synthetic methods to yield polycyclic heteroarenes have largely relied on metal-mediated arylation reactions requiring pre-functionalised substrates. However, the functionalisation of unactivated azines has been restricted because of their intrinsic low reactivity. Herein, we report a transition-metal-free, radical relay pi-extension approach to produce N-doped polycyclic aromatic compounds directly from simple azines and cyclic iodonium salts. Mechanistic and electron paramagnetic resonance studies provide evidence for the in situ generation of organic electron donors, while chemical trapping and electrochemical experiments implicate an iodanyl radical intermediate serving as a formal biaryl radical equivalent. This intermediate, formed by one-electron reduction of the cyclic iodonium salt, acts as the key intermediate driving the Minisci-type arylation reaction. The synthetic utility of this radical-based annulative pi-extension method is highlighted by the preparation of an N-doped heptacyclic nanographene fragment through fourfold C-H arylation. The functionalisation of unactivated azines has been restricted because of their intrinsic low reactivity. Here the authors show a transition-metal-free, radical relay pi-extension approach to produce N-doped polycyclic aromatic compounds directly from simple azines and cyclic iodonium salts

    Efficacies of the new Paclitaxel-eluting Coroflex Pleaseā„¢ Stent in percutaneous coronary intervention; comparison of efficacy between Coroflex Pleaseā„¢ and Taxusā„¢ (ECO-PLEASANT) trial: study rationale and design

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    <p>Abstract</p> <p>Background</p> <p>Previous randomized trials have showed the superiority of Paclitaxel-eluting stent over bare metal stent in angiographic and clinical outcomes. Coroflex Pleaseā„¢ stent is a newly developed drug eluting stent using the Coroflexā„¢ stent platform combined with the drug paclitaxel contained in a polymer coating. PECOPS I trial, one-arm observational study, showed that the clinical and angiographic outcomes of Coroflex Pleaseā„¢ stent were within the range of those of Taxus, the 1<sup>st </sup>generation paclitaxel-eluting stent (PES). However, there have been no studies directly comparing the Coroflex Pleaseā„¢ stent with the Taxus Liberteā„¢ stent that is the newest version of Taxus. Therefore, prospective, randomized trial is required to demonstrate the non-inferiority of Coroflex Pleaseā„¢ stent compared with Taxus Liberteā„¢ stent in a head-to-head manner.</p> <p>Methods</p> <p>In the comparison of Efficacy between COroflex PLEASeā„¢ ANd Taxusā„¢ stent(ECO-PLEASANT) trial, approximately 900 patients are being prospectively and randomly assigned to the either type of Coroflex Pleaseā„¢ stent and Taxus Liberteā„¢ stent via web-based randomization. The primary endpoint is clinically driven target vessel revascularization at 9 months. The secondary endpoints include major cardiac adverse events, target vessel failure, stent thrombosis and angiographic efficacy endpoints.</p> <p>Discussion</p> <p>The ECO-PLEASANT trial is the study not yet performed to directly compare the efficacy and safety of the Coroflex Pleaseā„¢ versus Taxus Liberteā„¢ stent. On the basis of this trial, we will be able to find out whether the Coroflex Pleaseā„¢ stent is non-inferior to Taxus Liberteā„¢ stent or not.</p> <p>Trial registration</p> <p>ClinicalTrials.gov number, NCT00699543.</p

    Adsorptive molecularly imprinted composite membranes for chiral separation of phenylalanine

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    Two types of composite imprinted membranes, i.e., composite membrane comprised of D-Phe imprinted beads and D-Phe imprinted membrane or DCM and composite membrane comprised of L-Phe imprinted beads and L-Phe imprinted membranes or LCM, were synthesized by phase inversion technique after a uniform dispersion of beads within the polymeric solutions using simple physico-mechanical process. The assemblies of the prepared DCM, LCM and control membranes were employed in ultrafiltration for chiral separation of D, L-Phenylalanine racemate solution. DCM and LCM showed an improved adsorption capacity (0.334 mg g-1 and 0.365 mg g-1 respectively), and adsorption selectivity (2.72 and 2.98 respectively). However, the percent rejection of the template and counter enantiomer were lower than that of control membranes. Compared to control membrane, the DCM and LCM showed inverse permselectivity. These composite membranes having better adsorption and separation ability for Phenylalanine racemate solution will be suitable in the future for various other applications

    The Effect of Lithotomy Position on Hyperbaric Tetracaine Spinal Anesthesia

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    Synthesis of 18F-Labeled Aryl Fluorosulfates via Nucleophilic Radiofluorination

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    Sulfuryl fluoride gas is a key reagent for SO2F transfer. However, conventional SO2F transfer reactions have limited F-18-radiochemistry translation, due to the inaccessibility of gaseous [F-18] SO2F2. Herein, we report the first SO2F2-free synthesis of aryl [F-18]fluorosulfates from both phenolic and isolated aryl imidazylate precursors with cyclotron-produced F-18(-) . The radiochemical yields ranged from moderate to good with excellent functional group tolerance. The reliability of our approach was validated by the automated radiosynthesis of 4-acetamidophenyl [F-18]fluorosulfate
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