RESUMEN
[reaction: see text]. Chiral dirhodium(II) complexes, Rh2(O2CCF3)2(PC)2, [PCH = (p-CH3C6H4)3P, (m-CH3C6H4)3P], provide an excellent yield and a high enantiocontrol in the cyclopropanation of alpha-diazo ketones with gamma and delta double bonds. The ee values are significantly dependent on the solvent used; the best results are obtained using pentane.
RESUMEN
Two new dirhodium(II) catalysts of general formula Rh(2)(N-O)(2)[(C(6)H(4))P(C(6)H(5))(2)](2) (N-O = C(4)H(4)NO(2)) are prepared, starting from Rh(2)(O(2)CCH(3))(2)(PC)(2)L(2) [PC = (C(6)H(4))P(C(6)H(5))(2) (head-to-tail arrangement); L = HO(2)CCH(3)]. The thermal reaction of Rh(2)(O(2)CCH(3))(2)(PC)(2).L(2) with the neutral succinimide stereoselectively gives one compound that according to the X-ray structure determination has the formula Rh(2)(C(4)H(4)NO(2))(2)[(C(6)H(4))P(C(6)H(5))(2)](2) (1). It corresponds to the polar isomer with two bridging imidate ligands in a head-to-head configuration. However, stepwise reaction of Rh(2)(O(2)CCH(3))(2)(PC)(2).L(2) with (CH(3))(3)SiCl and potassium succinimidate yields a mixture of 1 and one of the two possible isomers (structure B) with a head-to-tail configuration of the imidate ligands, Rh(2)(C(4)H(4)NO(2))(2)[(C(6)H(4))P(C(6)H(5))(2)](2) (2), also characterized by X-ray methods. In solution, compound 2 undergoes slow isomerization to 1; the rate of this process is enhanced by the presence of acetonitrile. Compounds 1 and 2 are obtained as pure enantiomers starting from (M)- and (P)-Rh(2)(O(2)CCH(3))(2)(PC)(2).L(2) rather than from the racemic mixture. Their enantioselectivities in cyclopropanation of 1-diazo-5-penten-2-one are similar to those reported for the dirhodium amidate catalysts.
Asunto(s)
Anafilaxia/prevención & control , Equinococosis/diagnóstico , Complicaciones Intraoperatorias/prevención & control , Arteria Pulmonar/parasitología , Toracotomía , Adyuvantes Anestésicos/administración & dosificación , Adyuvantes Anestésicos/uso terapéutico , Adulto , Antiinflamatorios/administración & dosificación , Antiinflamatorios/uso terapéutico , Clorfeniramina/administración & dosificación , Clorfeniramina/uso terapéutico , Equinococosis/cirugía , Hemoptisis/diagnóstico , Hemoptisis/etiología , Hemoptisis/parasitología , Antagonistas de los Receptores Histamínicos/administración & dosificación , Antagonistas de los Receptores Histamínicos/uso terapéutico , Humanos , Masculino , Metilprednisolona/administración & dosificación , Metilprednisolona/uso terapéutico , Midazolam/administración & dosificación , Midazolam/uso terapéutico , Enfermedades Profesionales/diagnóstico , Enfermedades Profesionales/parasitología , Enfermedades Profesionales/cirugía , Medicación Preanestésica , Arteria Pulmonar/cirugía , Ranitidina/administración & dosificación , Ranitidina/uso terapéuticoRESUMEN
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Asunto(s)
Adulto , Masculino , Humanos , Toracotomía , Midazolam , Metilprednisolona , Medicación Preanestésica , Ranitidina , Arteria Pulmonar , Antiinflamatorios , Clorfeniramina , Equinococosis , Anafilaxia , Adyuvantes Anestésicos , Antagonistas de los Receptores Histamínicos , Hemoptisis , Complicaciones Intraoperatorias , Enfermedades ProfesionalesRESUMEN
The reactivity of the tetranuclear metallated palladium compound (Pd[mu 2-(C6H4)PPh2]Br)4 (1) with different ligands has been investigated with the aim of evaluating the influence of the entering ligand on the nature of the reaction products. The results confirmed the ability of the ligand [(C6H4)PPh2]- to expand a bridging [mu 2-] or a chelating [eta 2-] coordination mode, depending on the auxiliary ligands present in the complex. Bulky phosphines stabilize mononuclear species of formula (Pd[eta 2-(C6H4)PPh2]Br[P]), with a four-atom metallocycle, while small phosphines give dinuclear compounds. The molecular structures of three different metalated palladium compounds have been determined by single-crystal X-ray crystallography; the tetranuclear (Pd[mu 2-(C6H4)PPh2]Cl)4 (2), the dinuclear(Pd[mu 2-(C6H4)PPh2]Br[PMe3])2 (3), and the mononuclear (Pd[eta 2-(C6H4)PPh2]Br[PCBr]), (PCBr = P(o-BrC6H4)Ph2) (9) were obtained, the first one by halogen exchange reaction and the others by frame degradation of 1.
RESUMEN
We have studied a group of 8 patients that presented the Usher syndrome. We have analyzed their family genealogic tree, showing the hereditary pattern found. We have analyzed the cochlear and vestibular functions. The retinoic and ophthalmologic complications are evaluated. We have searched for possible olfactory and gustative neuroreceptors disease.