芳基硼酸与溴代芳烃的三苯基膦钯催化偶联反应

芳基硼酸在三苯基膦钯催化下，与溴代芳烃偶联反应，得到较高收率的不对称联苯衍生物。     

Gold and gold-palladium coated polypropylene grafts in a S. epidermidis wound infection model

The pig is a common large animal for experimental settings in many fields of surgery. In experimental surgery, there is a need for different narcotic procedures depending on the complexity of the surgical investigation. Narcotic procedures have to be safe, easy to handle, and should not influence the experimental results. We hereby present important aspects of handling and narcotic procedures for pigs. The aim of this publication is to supply an introduction for young surgical investigators who are planning or already have started investigations using pigs as an experimental animal. This publication is based on our institutional experience of narcotic and surgical procedures in more than 400 cases.     

Occupational hypersensitivity to metal salts, including platinum, in the secondary industry

BACKGROUND: Exposure to platinum group elements (PGEs) - platinum (Pt), palladium (Pd), rhodium (Rh) and iridium (Ir) - may cause acute toxicity or hypersensitivity with respiratory symptoms, urticaria and (less frequently) contact dermatitis. Our aim was to determine the prevalence and the clinical characteristics of hypersensitivity to platinum salts and to other elements of the platinum group. METHODS: A total of 153 subjects working in a catalyst manufacturing and recycling factory were examined. The examination consisted of a work exposure and medical questionnaire, physical examination, skin prick test for PGEs and other common aeroallergens, and patch tests for PGEs. Skin prick tests and patch tests were performed with H(2)[PtCl(6)], K(2)[PtCl(4)], Na(2)[PtCl(6)], IrCl(3), RhCl(3), PdCl(2), aqueous solutions at different concentrations. RESULTS: Positive prick test reactions to Pt-salts at various concentrations were found in 22 (14.4%) of 153 workers; eight had simultaneous reactions to all Pt-salts tested; seven had positive responses to H(2)[PtCl(6)] only; four had simultaneous positive reactions to both H(2)[PtCl(6)] and K(2)[PtCl(4)]; three had positive reactions to H(2)[PtCl(6)] and Na(2)[PtCl(6)]. Three of 22 had positive reactions to H(2)[PtCl(6)] and IrCl(3) solutions, two of these had positive reactions to H(2)[PtCl(6)], IrCl(3) and RhCl(3) solutions. Positive patch test reactions to platinum salts at day 2 were seen in two of 153 subjects. CONCLUSIONS: The results of this study demonstrate that Pt-salts are important allergens in the catalyst industry and that the clinical manifestations involve both the respiratory system and the skin. Hexachloroplatinic acid should be considered the most important salt to use for skin prick tests.     

Highlights of C (sp2)–H hydrogen isotope exchange reactions

The highlights of C (sp²)–H hydrogen isotope exchange (HIE) methods developed over the past 10 years are summarized in this review. Major developments include improved Ir(I) catalysts with greater functional group and solvent compatibility and the development of novel base metal catalysts for HIE. In addition, a number of novel Ru-based catalysts have been developed with promising activity. In the area of Pt- and Pd-catalysed exchange, in addition to new advances on heterogeneous Pt- and Pd-catalysed HIE by Sajiki and Shevchenko, a number of groups have reported on homogenous catalysts of Pt and Pd that show an interesting activity and selectivity.     

1-(Triethoxysilyl)buta-1,3-dienes—New Building Blocks for Stereoselective Synthesis of Unsymmetrical (E,E)-1,4-Disubstituted 1,3-dienes

A convenient methodology for the highly stereoselective synthesis of unsymmetrical (1E,3E)-1,4-disubstituted 1,3-dienes based on palladium-catalyzed Hiyama cross-coupling reaction of 1-(triethoxysilyl)-substituted buta-1,3-dienes with aryl iodides is reported.     

Synthesis of a high specific activity methyl sulfone tritium isotopologue of fevipiprant (NVP‐QAW039)

The synthesis of a triple tritiated isotopologue of the CRTh2 antagonist NVP‐QAW039 (fevipiprant) with a specific activity >3 TBq/mmol is described. Key to the high specific activity is the methylation of a bench‐stable dimeric disulfide precursor that is in situ reduced to the corresponding thiol monomer and methylated with [³H₃]MeONos having per se a high specific activity. The high specific activity of the tritiated active pharmaceutical ingredient obtained by a build‐up approach is discussed in the light of the specific activity usually to be expected if hydrogen tritium exchange methods were applied.     

A convenient method for palladium‐catalyzed reductive deuteration of organic substrates using deuterated hypophosphite in D2O

A convenient method for the deuteration of organic substrates using deuterated hypophosphite as the deuterium source was investigated. Transfer deuteration of organic substrates, such as aromatic halides, alkenes, alkynes, epoxides, and O‐benzyl derivatives, in the presence of palladium on carbon in deuterium oxide proceeded efficiently to give the corresponding deuterated products in excellent yields with high deuterium contents.     

Preparation of Palladium-Supported Periodic Mesoporous Organosilicas and their Use as Catalysts in the Suzuki Cross-Coupling Reaction

Three periodic mesoporous materials, i.e., two organosilicas with either ethylene or phenylene bridges and one silica, have been used as supports for Pd nanoparticles. All Pd-supported samples (1.0 wt%) were prepared by the incipient wetness method and subsequently reduced in an H₂ stream at 200 °C. Both hydrogen chemisorption and temperature programmed reduction experiments revealed significant differences depending on the support. Pd²⁺ species were more reducible on the mesoporous organosilicas than on their silica counterpart. Also, remarkable differences on the particle morphology were observed by transmission electron microscopy. All Pd-supported samples were active in the Suzuki cross-coupling reaction between bromobenzene and phenylboronic acid.     

Carrier‐effect on palladium‐catalyzed,nucleophilic 18F‐fluorination of aryl triflates

A recently published palladium‐catalyzed preparation of fluoroarenes starting from caesium fluoride attracted interest as a new alternative for radiofluorination. To test this method, a suitable protocol for the synthesis of 4‐[¹⁸F]fluorotoluene and 1‐[¹⁸F]fluoronaphthalene as model systems has been developed. The possibility to perform the reaction under no‐carrier‐added condition was of special interest. It was found out, however, that the reaction requires the presence of carrier, thus limiting the method to syntheses of radiotracers with low specific activity. Copyright © 2012 John Wiley & Sons, Ltd.