Direct reductive amination of carbonyl compounds using bis(triphenylphosphine) copper(I) tetrahydroborate

A direct reductive amination protocol for aldehydes/ketones using bis(triphenylphosphine) copper(I) tetrahydroborate as a novel reducing agent in the presence of sulfamic acid has been developed. The reagent chemoselectively reduces the imine moiety and does not affect other reducible functionalities such as chloro, nitro, cyano and methoxy.     

Thermal decomposition of bis[carbonyl(μ-alkyl(aryl)thio)η5-cyclopentadienyliron] complexes

Conclusion The thermal decomposition of [FeCp(SR)CO]₂ complexes, where B is Et or Ph, leads to ferrocene and a mononuclear complex, FeCpSE(SO)₂. Stable polynuclear complexes are not formed.Deceased.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 655–657, March, 1987.     

The photolysis of Chlorocarbonylbis(triphenylphosphine)iridium(I) in chloroform

Under 254 or 313 nm irradiation in chloroform, [IrCl(CO)(PPh3)2] is converted cleanly to [IrCl2(CO)H(PPh3)2] through the addition of HCl, produced photochemically. Under 254 nm irradiation, some of the reaction of [IrCl(CO)(PPh3)2] occurs by direct photolysis of chloroform, though a greater contribution arises from a reaction initiated through absorption of light by the metal complex. Under 313 nm irradiation, essentially all of the reaction is metal-initiated. The linear dependence of the reaction rate on light intensity and on the fraction of light absorbed by the Ir(I) complex as well as the lack of a deuterium isotope effect rule out a radical process. Instead it is proposed that an association complex between excited state [IrCl(CO)(PPh3)2] and CHCl3 leads to dissociation of a chlorine atom from CHCl3, yielding HCl after abstraction of a hydrogen from another CHCl3. HCl then adds to a ground state [IrCl(CO)(PPh3)2] complex.     

Öffnung einer FeFe-Bindung in [Fe3(CO)9(μ3-SR)]− durch elektrophile reagenzien aus der fünften und sechsten hauptgruppe

The anions of the cluster salt [Fe₃(CO)₉(μ₃-SR)][t-C₄H₉NH₃] (R = t-C₄H₉ (I); R = C₆H₁₁ (II)) react with monohalides XCl (X = PR′₂, AsR′₂, SbR′₂, SR′, SeR′; R′ = Alkyl, Aryl) to give the neutral complexes Fe₃(CO)₉(μ₃-SR)(μ₂-X) (III–XII).X-ray analyses show that in these products one of the FeFe bonds is opened and bridged by the μ₂-ligand X. In some cases, the synthesis of the trinuclear clusters is accompanied by formation of the dinuclear species Fe₂(CO)₆(μ₂-SR)(μ₂-X) (X = PPh₂, (XIII); X = SPh, (XIV) as by-products. In a formal sense this corresponds to loss of an Fe(CO)₃ group from the trinuclear complexes. The geometry of Fe₂(CO)₆(μ₂-SC₆H₁₁)(μ₂-PPh₂) (XIII) has been elucidated by X-ray analysis.     

Syntheses and Crystal Structures of Bis-[oxo-bis(p-ferrocenylbenzoxy di-n-propyltin)](I) and Bis[oxo-bis(β-ferrocenoylpropionyloxy di-n-propyltin )](II)

1 INTRODUCTION The studies of organotin compounds are of current interest owing to their wide range of applications such as biocides and thermal stabilizers for PVC plastic etc. Besides, the pharmaceutical properties such as the antitumor activities of organotin carboxylates have been investigated[1, 2]. In recent years, reports of synthesis and structural elucidation of various organotin carboxylic esters have appeared, revealing various new structural possibilities[3]. Since Kealy an…     

Synthesis and structures of monomeric [chloro(isatin-3-thiosemicarbazone)bis(triphenylphosphine)]copper(I) and dimeric [dichlorobis(thiophene-2-carbaldehyde thiosemicarbazone)bis(triphenylphosphine)]dicopper(I)] complexes

Reaction of copper(I) chloride with thiophene-2-carbaldehyde thiosemicarbazone (Httsc) in acetonitrile in the presence of Ph₃P yielded a sulfur-bridged dimer [Cu₂Cl₂(μ₂-S-Httsc)₂(PPh₃)₂] · 2CH₃CN (1), while a similar reaction with isatin-3-thiosemicarbazone (H₂itsc) formed a monomer, [CuCl(H₂itsc)(Ph₃P)₂] · 2CH₃CN (3). Furan-2-carbaldehyde thiosemicarbazone (Hftsc) also formed a compound of the composition [Cu₂Cl₂(Hftsc)₂(PPh₃)₂] · 2H₂O (2). Complexes 1–3 have been characterized using elemental analysis, IR, ¹H and ³¹P NMR spectroscopy and single crystal X-ray crystallography (1 and 3). Acetonitrile is engaged in hydrogen bonding with the chlorine atom {NCCH₂–H?Cl)}, which is necessary for the stabilization of the bridging sulfur in 1. In compound 3, however, acetonitrile is strongly hydrogen bonded to the NH hydrogen of the isatin ring {CH₃CN?NH(isatin)} and not to the chlorine atom. The Cu?Cu contact of 2.7719(5) Å in dimer 1 is close to twice the van der Waals radius of the Cu atom (2.80 Å).     

Thermal decomposition of [bis(salicylaldehydato)cadmium(II)] to CdS nanocrystals

The present investigation reports, the novel synthesis of nanocrystals CdS using thermal decomposition of [bis(salicylaldehydato)cadmium(II)], as a new precursor, and elemental sulfur in oleylamine. The as-synthesized CdS crystals have diameters about 10 nm. The products were characterized by X-ray diffraction (XRD) transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), ultraviolet–visible (UV–Vis) spectroscopy and Fourier transformed infrared (FT-IR) spectra. The results of this paper show that the shape and size of cadmium sulfide nanocrystals can be controlled systematically by adjusting certain reaction parameters, such as the reactant concentration, the reaction temperature and the reaction time. Cadmium sulfide nanoparticles and nanorods with different lengths have been successfully prepared.     

Coordination,oligomerisation and transfer hydrogenation of acetylenes by some ruthenium and osmium carboxylates: Crystal and molecular structures of bis(trifluoroacetato)carbonyl-(methanol) bis(triphenylphosphine)ruthenium(II) and (1,4-diphenylbut-1-en-3-yn-2-yl)trifluoroacetato-(carbonyl) bis(triphenylphosphine)ruthenium(II)

The hydrides [MH(O₂CCF₃)(CO)(PPh₃)₂] (M = Ru or Os) react with disubstituted acetylenes PhCCPh and PhCCMe to afford vinylic products [M{C(Ph)CHPh}(O₂CCF₃)(CO)(PPh₃)₂] and [M{C(Ph)CHMe}(O₂CCF₃)(CO) (PPh₃)₂]/[M{C(Me)CHPh}(O₂CCF₃)(CO)(PPh₃)₂] respectively. Acidolysis of these products with trifluoroacetic acid in cold ethanol liberates cis-stilbene and cis-PhHCCHMe respectively thus establishing the cis-stereochemistry of the vinylic ligands. The complexes [M(O₂CCF₃)₂(CO)(PPh₃)₂] formed during the acidolysis step undergo facile alcoholysis followed by β-elimination of aldehyde to regenerate the parent hydrides [MH(O₂CCF₃)(CO)(PPh₃)₂] and thereby complete a catalytic cycle for the transfer hydrogenation of acetylenes. The molecular structure of the methanol-adduct intermediate, [Ru(O₂CCF₃)₂(MeOH)(CO)(PPh₃)₂] has been determined by X-ray methods and shows that the coordinated methanol is involved in H-bonding with the monodentate trifluoroacetate ligand [MEO-H---OC(O)CF₃; O...O = 2.54 Å]. The hydrides [MH(O₂CCF₃)(CO) (PPh₃)₂]react with 1,4-diphenylbutadiyne to afford the complexes [M{C(CCPh)CHPh} (O₂CCF₃)(CO)(PPh₃)₂]. The ruthenium product, which has also been obtained by treatment of [RuH(O₂CCF₃)(CO)(PPh₃)₂] with phenylacetylene, has been shown by X-ray diffraction methods to contain a 1,4-diphenylbut-1-en-3-yn-2-yl ligand. The osmium complexes [Os(O₂CCF₃)₂(CO)(PPh₃)₂], [OsH(O₂CCF₃)(CO)(PPh₃)₂] and [Os{C(CCPh)CHPh}(O₂CCF₃)(CO)(PPh₃)₂] all serve as catalysts for the oligomerisation of phenylacetylene. Acetylene reacts with [Ru(O₂CCF₃)₂(CO)(PPh₃)₂] in ethanol to afford the vinyl complex [Ru(CHCH₂)(O₂CCF₃)(CO)(PPh₃)₂].     

The stereochemistry of Si—D addition to hydridocarbonyltris(triphenylphosphine)iridium(I)

Triphenyldeuteriosilane adds to hydridocarbonyltris(triphenylphosphine)iridium(I) to give a-hydrido-b-deuterido-c-triphenylsilyl-d,e-bis(triphenylphosphine)carbonyliridium(I). In the presence of excess Ph₃SiD, the latter compound undergoes rapid H/D exchange at the hydride position.     

Bis[iridium(I)] complex of inverted N-confused porphyrin

The reaction of N-confused tetraphenylporphyrin with IrCl(CO)2(p-toluidine) gave a novel bis[iridium(I)] complex, wherein the confused pyrrole ring took an inverted conformation.