RESUMO
The catalytic potential of palladium(II) complexes with chelating N-phosphanyl-N-heterocyclic carbenes featuring a saturated imidazolin-2-ylidene or tetrahydropyrimid-2-ylidene ring has been investigated in intermolecular alkyne hydroamination reactions. The complexes were found to be among the most active Pd-based catalysts for these processes and to enable the use of low reaction temperatures (40 °C) and of solventless conditions. The Pd complexes require activation by 2 equiv of a silver salt to remove chlorido ligands from the metal coordination sphere; they can however also be presynthesized in active form, which allows their use under silver-free conditions. The hydroamination reaction was found to efficiently proceed with terminal alkynes and different ring-substituted, primary arylamine substrates.
RESUMO
Ten cases of well documented pumonary nocardiosis were seen in the citu of Medellin, Colombia, between 1975 and 1984. Among them there were 5 men and 5 women. All 10 patients had respiratory symptoms and some type of immunosupresive disease. The radiological findings in this group were similar to those described: pulmonary infiltrates, lung abscesses and calcifications, pleural effusions, pneumothorax and empyema. The authors on pulmonary emphasize the scarcity of colombian literature on pulmonary nocardiosis and the fact that it can be easily diagnosed if adequate techniques are available
