1,721,029 research outputs found
Carbamoyl and alkoxycarbonyl complexes of palladium(II) and platinum(II)
No full textCarbamoyl and alkoxycarbonyl complexes of Pd(II) and Pt(II) of the type (pnp)M(CONHR)Cl [pnp = 2,6-bis(diphenylphosphinomethyl)pyridine; M = Pd, R = Ph, p-tolyl, p-MeOC6H4, cyclohexyl, Me3C; M = Pt, R = Ph], (pnp)Pd(CONPr2)Cl, (pnp)M(CO2R)Cl (M = Pd, R = Ph, Me; M = Pt, R = Me) and (pnp)Pd(CO2Me)2 result from reaction of (pnp)MCl2 with CO and amines or alkoxides at room temp. and atm. pressure. The carbamoyl complexes react with bases to give urethane or (PhNH)2CO, depending upon the exptl. conditions
Chloride based ionic liquids as promoting agents for Meerwein reaction in solventless conditions
No full textChloride based ionic liquids were used as chloride source in Meerwein reaction either in [bmin]X (bmim = 1-butyl-3methylimidazolium, X = BF4, PF6) as solvents or in solventless conditions. Satisfactory yields (49-71%) with diversely substituted diazonium salts were achieved by using 1,3-dibutylimidazoliurn chloride in the presence of a bimetallic Zn/Cu catalyst
Catalytic reduction of nitrosobenzene by carbon monoxide using nitrosobenzene complexes of transition metals
No full textNew nitrosoarene complexes of Ru(II), Pd(II), Pt(II), and Rh(I) have been synthesized. Their reactions with CO in the solid state and in ethanol suspension suggest formation of a nitrene intermediate. The catalytic redn. of nitrosobenzene has been also studied; azoxybenzene and urethane are the main products in ethanol, whereas azoxybenzene, Ph isocyanate and diphenylurea are obtained in benzene. Increase in the temp. and the CO pressure results in increase of the yields of the carbonylated products
Catalytic Pauson-Khand reactions in ionic liquids
No full textIonic liquids (ILs) are suitable media for the Co-2(CO)(8)-catalysed intramolecular and intermolecular Pauson-Khand (PK) annelation, provided that the reaction is carried out under a CO pressure of 10 bar. Two diethyl allyl propargyl malonates were quantitatively converted into the relevant cyclopentenones, whereas heteroatom tethered enynes gave lower yields in their cyclocarbortylation products. A moderate yield in the corresponding Pauson-Khand product was obtained reacting phenylacetylene with norbornene
Hydrogenation of Ethyl 12-Trimethylsilyl-9-dodecyn-11-enoate by Isocyanide Polymer Rh(PPh3)3Cl
No full textSynthesis and reactivity toward gas molecules of chloro-2,6-di(diphenylphosphinomethyl)pyridinerhodium(I)
No full textThe prepn. of RhClL [L = 2,6-bis(diphenylphosphinomethyl)pyridine] and its adducts with O2, CO, CO2, SO2, and tertiary phosphines is described. The reactions of the dioxygen adduct with SO2 and CO are also reported
Metal complexes of N-allylaniline. A palladium(II) complex with co-ordination number of greater than four
No full textN-Allylaniline (aa) can act as a uni- or bi-dentate ligand in complexes of composition [PdCl2(aa)2] affording an orange-yellow (1) and a dark red isomer (2). The palladium in (1) is four-co-ordinate and planar, with the olefin group unbound in benzene and dimethyl sulphoxide (dmso) solution. The olefin groups in (2) are bound to the palladium, which, in solution (NN-dimethylformamide, dmso, or acetone), is at least five-co-ordinate. Both complexes lose methylacetylene and allene to form trans-[PdCl2(NPhH2)2] on standing in the solid state or in solution. Isomer (1) requires elevated temperatures and long reaction times, but (2) decomposes readily at room temperatur
2,6-Bis(diphenylphosphinomethyl)pyridine complexes of nickel(II), cobalt(II), iron(II)
No full textSome new 2,6-bis(diphenylphosphinomethyl)pyridine (pnp) complexes of Ni(II), Co(II), and Fe(II) were prepd. and their phys. properties were detd. and compared with those of some previously described Ni(II) complexes. A 5-coordinate mol. structure (distorted trigonal bipyramidal), instead of the previous square-planar, is now suggested for [Ni(pnp)2]2+. For Ni(pnp)(NCS)2, previously described as a mixt. of low-spin and high-spin forms of a 5-coordinated mol., the formulation [Ni(pnp)NCS][Ni(pnp)(NCS)3], which receives strong support from the exptl. data, is suggested. The 6-coordinated Ni(pnp)(NO3)2, the 5-coordinated high-spin Co(pnp)(NO3)2 and Fe(pnp)(NO3)2, and the 6-coordinated low-spin [Co(pnp)2](ClO4)2 and [Fe(pnp)2](ClO4)2 are also described. The equil. const. for the hydration reaction of Ni(pnp)Cl2 in BuOH-H2O soln. is detd
Rhodium and iridium complexes containing nitrosoarene ligands
No full textClML(p-RC6H4NO) (I, M = Rh, Ir; L = cyclooctadiene, norbornadiene; R = H, Me, Me2N, Br, NO2) were prepd. in 30-80% yields by treating (ClML)2 with p-RC6H4NO in Me2CO at room temp. The reaction of I with Ph3P and CO was studied
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