A novel strategy for the synthesis of uracil derivatives using bis(pentafluorophenyl)imidodicarbonate

The disclosure herein describes a novel strategy for the synthesis of uracil derivatives via a solvent-free microwave cyclocondensation reaction using bis(pentafluorophenyl)imidodicarbonate.     

New palladium(II)-catalyzed asymmetric 1,2-dibromo synthesis

[reaction: see text] The oxidation of olefins by chiral monometallic and bimetallic Pd(II)-Cu(II) catalysts in bromide-containing aqueous-THF reaction mixtures produced chiral 1,2-dibromides. With alpha-olefins, the ee's were about 95% while most of the internal alkenes gave somewhat lower enantioselectivities ( approximately 80%).     

The chemistry of binuclear palladium(II) and platinum(II) complexes

The chemistry of binuclear palladium(II) and platinum(II) complexes has been reviewed. This review deals with complexes derived from various classes of ligands and covers various aspects, viz. synthesis, spectroscopic and structural features and chemical reactivity, of these complexes. Applications of these complexes are briefly described in the respected sections.     

A simple route for the synthesis of novel norcantharimide derivatives via acidolysis with hydrochloric acid(gas)

In this work, seven new norcantharimide derivatives were synthesized by an acidolysis method. The compounds were prepared by acidolyzing trans-1,4-diacetate and trans-1,2-chloroacetate structures, which were obtained by stereospecific cleavage of the internal etheric bond of the tricyclic imides. The HCl_(gas) was produced from the reaction of H₂SO₄ with NaCl. The resulting gas was bubbled into the reaction mixture. Trans-1,4-diacetate and trans-1,2-chloroacetate were thus acidolyzed, and the corresponding diol and halohydrin products were obtained respectively in moderate overall yields from low-cost starting materials, using simple and easily scalable chemistry. The products were characterized by means of spectroscopic techniques. The synthesized compounds have high potential as anticancer agents and can be valuable for studies in this area.     

New biimidazole and bibenzimidazole derivatives: mono and binuclear palladium(II) or platinum(II) complexes and heterobinuclear palladium(II)-rhodium(I) or platinum(II)-rhodium(I) complexes

Novel neutral biimidazolate or bibenzimidazolate palladium(II) and platinum(II) complexes of the type M(NN)₂(dpe) [M = Pd, Pt; (NN)₂^2? = BiIm^2?, BiBzIm^2?. dpe = 1,2-bis(diphenylphosphino) ethane] have been obtained by reacting MCl₂(dpe) with TI₂(NN)₂. Complexes M(NN)₂(dpe) which are Lewis bases react with HClO₄ or [M(dpe)(Me₂CO)₂](ClO₄)₂ to yield, respectively, mononuclear cationic complexes of general formula [M{H₂(NN)₂](dpe) (M = Pd, Pt; H₂(NN)₂ = H₂BiIm, H₂BiBzIm) and homobinuclear palladium(II) or platinum(II) cationic complexes of the type [M₂{μ - (NN)₂}(dpe)₂](ClO₄)₂. Reactions of M(BiBzIm)(dpe) with [Rh(COD) (Me₂CO)_X](ClO₄) render similar heterobinuclear palladium(II)-rhodium(I) and platinum(II)-rhodium(I) cationic complexes, of general formula [(dpe)M(μ-BiBzIm)Rh(COD)](ClO₄) (M = Pd, Pt; COD = 1,5-cyclooctadiene). Di- and mono-carbonyl derivatives [(dpe)M(μ-BiBzIm)Rh(CO)L](ClO₄) (M = Pd, Pt; L = CO, PPh₃) have also been prepared. The structures of the resulting complexes have been elucidated by conductance studies and IR spectroscopy.     

Bis(2,4,6-trifluorophenyl) derivatives of palladium(II)

Summary The organopalladium(II) complexes: Pd(2,4,6-C₆F₃H₂)₂L₂ [L=triphenylphosphine(PPh₃), methyldiphenylphosphine(PPh₂Me), dimethylphenylphosphine-(PPhMe₂) or pyridine(py); L₂=1,2-bis(diphenylphosphino)ethane(dpe), 2,2-bipyridine(bipy), 1, 10-phenanthroline(phen) or ethylenediamine(en)] have been prepared by addition of the appropriate compound to the THF-dioxane solution resulting from the arylation of potassium tetrachloropalladate(II) with (2,4,6-C₆F₃H₂)MgBr. The i.r. data suggest that the py and PPhMe₂ compounds are thecis-isomers, whereas the PPh₃ and PPh₂Me compounds have thetrans configuration.¹H- and¹⁹F-n.m.r. data for the compounds are reported.     

Dichloro-bis(pentafluorophenyl)(chelate) complexes of palladium(IV)

Four organometallic palladium(IV) complexes: Cl₂(C₆F₅)₂Pd(LL) (LL being a bidentate nitrogen-donor ligand) have been prepared by the oxidative addition of chlorine to the corresponding bis(pentafluorophenyl)palladium(II) complexes, (C₆F₅)₂Pd(LL). Some of their properties are described.     

A convenient synthesis of high-loaded palladium(II) ROMP polymers

Bis[1-(5-norbornen-2-yl)butan-1,3-dionato]palladium(II) was conveniently prepared from 5-acetoacetyl-2-norbornene and sodium tetrachloropalladate. The former could be subjected to ROMP to give a highly-loaded palladium(II) ROMP polymer with a palladium loading of 23% by weight.     

A novel synthetic route for the total synthesis of (±)-uleine

In this study, a new synthetic route for the total synthesis of (±)-uleine is described. The important step in the synthesis of this alkaloid consists of an intramolecular cyclization of the D ring of the azocino[4,3-b]indole skeleton. Reduction of (N-methyl){3-β-ethyl-4-oxo-2,3,4,9-tetrahydrospiro[1H-carbazole-1,2′(1,3)dithiolane]-2-yl}-2-acetamide with borane yielded the corresponding (N-methyl){3-β-ethyl-4-hydroxy-2,3,4,9-tetrahydrospiro[1H-carbazole-1,2′(1,3)dithiolane]-2-yl}-2-acetamide, which underwent acid-catalyzed ring closure to produce azocino[4,3-b]indole core. Finally, the synthesis of (±)-uleine was completed through several steps from the azocino[4,3-b]indole core.     

Synthesis and structural characterization of binuclear palladium(II) complexes of salicylaldimine dithiosemicarbazones

A series of binuclear palladium(II) salicylaldiminato dithiosemicarbazone complexes have been synthesized and characterized. The palladium complexes were obtained by the reaction of various ethylene- and phenylene-bridged dithiosemicarbazones with Pd(PPh₃)₂Cl₂. The free salicylaldimine ligands and their palladium complexes were characterized by NMR and IR spectroscopies, ESI-mass spectrometry, elemental analyses and for two representative complexes also by X-ray diffraction. In both metal complexes, the solid-state structures show the two palladium centers to be coordinated in a slightly distorted square-planar geometry, which gives rise in each case to five- and six-membered chelate rings. The salicylaldimine thiosemicarbazone ligands coordinate to palladium in a tridentate manner, through the phenolic oxygen, imine nitrogen and thiolate sulfur atoms.     

氟班色林的合成新方法

本文通过醋酸碘苯促进的苯甲醛、N-苯基羟胺和三甲基氰硅烷的一锅法反应首先构建氟班色林的重要骨架苯并咪唑酮结构,随后,与1,2-二溴乙烷反应得到中间体8,接着在浓盐酸中水解,得到中间体9,最后与哌嗪盐酸盐10反应,以29%的总收率得到氟班色林11。所有化合物的结构经过1H NMR、13C NMR、HRMS表征。该方法具有原料价廉易得、副产物少、收率较高等特点。     

A novel binuclear copper(II) complex with fumarate and 1,10-phenanthroline

A MeOH solution of 1,10-phenanthroline reacts with Cu(fum)[fum = (OOCCH = CHCOO)^2–] to yield a novel binuclear copper(II) unsaturated dicarboxylate complex of general formula [Cu₂(fum)(phen)₄](fum) · 11H₂O, whose crystal structure has been determined by X-ray diffraction. Two copper(II) atoms are bridged by a fumarate group, and each copper(II) atom is coordinated to two 1,10-phenanthroline molecules in a distorted trigonal bipyramidal configuration. The i.r. spectrum shows the presence of the monodentate carboxylate ligand. The electronic reflectance spectrum in the solid state suggest that the d–d transitions of the complex is in a trigonal bipyramidal ligand field. The temperature-dependent magnetic susceptibility studies suggest that a weak ferromagnetic interaction exists between the two copper(II) atoms when the temperature exceeds 130 K.     

Reactions of platinum(O) and palladium(O) complexes with mercury(II) compounds: New methods for the synthesis of organic platinum and palladium derivatives

Conclusions A new group of reactions between Pt^o and Pd^o complexes with organic and heteroorganic Hg^II compounds was found and studied. The reaction involves the insertion of L_nM^o into the bond between mercury and the heteroelement. The bimetallic compounds formed may be isolated or undergo immediate demercuration leading to divalent platinum and palladium -derivatives, depending on the nature of the substituents and ligands and reaction conditions.Article published by a decision of the editorial board of this journal, dated December 3. 1981.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2069–2089, September, 1982.     

Catalytic asymmetric intramolecular aminopalladation: improved palladium(II) catalysts

[reaction: see text] Cobalt oxazoline palladacyclic (COP) complex 4 containing acetate as a bridging ligand is an excellent catalyst for asymmetric intramolecular aminopalladation to synthesize 4-vinyloxazolidin-2-ones in 91-98% ee. In contrast to previously reported Pd(II) catalysts, COP-OAc (4) promotes the asymmetric cyclization of (Z)-allylic N-tosylcarbamates without prior activation by silver salts.     

Synthesis and characterization of binuclear palladium(II) and platinum(II) complexes with a bridging hydroxypyridinate ligand

Summary Binuclear Pd^II and Pt^II complexes of the type [M₂Cl₂(-Opy)₂(PR₃)₂] [M = Pd or Pt; Opy = 2-OC₅H₄N (2-hydroxypyridinate ion); PR₃ = PEt₃, Pn-Bu₃, PMe₂Ph or PMePh₂] were synthesized and characterized by elemental analysis, ¹H- and ³¹P-n.m.r. spectroscopies. The Pd complexes exist in the sym trans form, whereas the corresponding Pt complexes were generated as different isomers.     

Pentafluorophenylthiolate derivatives of ruthenium(II), rhodium(I) and palladium(II)

Summary The pentafluorophenylthiolate anion [C₆F₅S]^– reacts with chloro-bridged binuclear complexes of Ru^II, Rh^I and Pd^II to give the compounds [(N-N)(PPh₃)₂Ru(SC₆F₅)]₂Cl₂ (1) (N-N = bipyridine), [LRh(SC₆F₅)]_n (L = cycloocta-1,5-diene (2) or norbornadiene (3), n = 2 and L = dicyclopentadiene (4) for which n is probably 4), [(PPh₃)Pd(SC₆F₅)Cl]₂ (5) and (MeS-CHMeCHMeSMe)Pd(SC₆F₅), (6).¹⁹F n.m.r. spectroscopy shows a variable number of isomers depending on the compound considered.     

A novel route to synthesis of flavones from salicylaldehyde and acetophenone derivatives

Convenient, facile, and alternate synthesis of medicinally important flavones is reported. The 2-hydroxychalcones derived from condensation between acetophenones and salicylaldehyde, underwent oxidative cyclization on heating in the presence of catalytic iodine, generating diversified flavones under solvent-free conditions. Eleven compounds have been synthesized in good to excellent yields and their mechanism of formation is described.