Deactivation of RuCl2(PPh3)3 during disproportionation of D-glucose in amide solvents

Abstract: Dimethyl formamide (DMF) can be a convenient source of the carbonyl ligand in the coordination chemistry of rhodium, ruthenium, iridium, and platinum. We have undertaken a thorough study concerning the course of this reaction. In a first step, DMF-containing complexes are produced, which is usually accompanied by chloride redistribution. Then, upon refluxing, carbonyl species in the same oxidation state are obtained, presumably as a result of HCl-mediated DMF decomposition. Provided that water levels are kept low, reduction can occur to provide the complexes [NH2(CH3)2][RhCl2(CO)2], [NH2(CH3)2][RuCl3(CO)2(DMF)], [RuCl2(CO)2(DMF)2], and [NH2(CH3)2][IrCl2(CO)2]. In the case of platinum, reduction is not effective and [NH2(CH3)2][PtCl3(CO)] is obtained. No carbonylpalladium species can be synthesized in this way, the reaction producing copious amounts of colloidal metal. Adding phosphanes to these chlorocarbonyl-containing solutions allows easy, one-step syntheses of a variety of complexes.

Abstract: The products of the reactions of copper(II) starting materials with 4-pyridyltetrazole (4-Hpt) in N,N-dimethylformamide (DMF)/methanol solutions are determined by the anion identity and concentration. In the absence of chloride, the 3-D open-framework material [Cu3(OH)3(4-pt)3(DMF)4]·5DMF·3MeOH (1·5DMF·3MeOH) is isolated, while variations in the chloride concentration yield the 2-D and 3-D materials, 2 and 3, respectively. All three structures exhibit trinuclear copper(II) building blocks: the triangular {Cu3(μ3-OH)}5+ core in 1 and {Cu3Cl4(4-pt)4(4-Hpt)2}2− and {Cu3Cl2(4-pt)8}4− chains in 2 and 3, respectively. All three materials display microporosity, which is highly dependent on the method of sample preparation.

Abstract: A mechanism for the transfer hydrogenation of ketones to secondary alcohols catalysed by HFe3(CO)11−1 (1) in the presence of Phase Transfer Catalysts (PTC) has been proposed using labelled hydrogen, NMR and IR techniques.

Abstract: Transfer hydrogenation of ketones to alcohols using iron carbonyls as catalysts in liquid-liquid phase occurs in the presence of phase transfer catalysts (PTC). Based on the percentage yield of the products, the efficiencies of the phase transfer agent, iron carbonyls and the donors are compared. Benzyltriethylammonium chloride and 18-crown-6 are equally effective and better than tricaprylmethylammonium chloride (Aliquat® 336). Among the three iron carbonyls the order of efficiency is Fe3(CO)12 > Fe2(CO)9 > Fe(CO)5. 1-Phenylethanol is a better donor than isopropanol. The relative ease of reducibility of various ketones increases with increasing reduction potential. The stereochemistry of reduction of 4-t-butylcyclohexanone is discussed.

Abstract: Homogeneous hydrogenation of two epimeric aldoses, d -glucose ( d -Glc) and d -mannose ( d -Man) was performed in water, with molecular hydrogen and by transfer hydrogenation catalyzed by [Ru-TPPTS] complex (TPPTS = trisodium salt of tri( m -sulfophenyl)phosphine). Both method proved effective, and revealed d -Man as more reactive aldose. Hydrogen transfer has been studied with various hydrogen donors: the most effective, but highly pH-dependent system has been found in Et 3 N/formic acid (azeotropic mixture 2:5) as the source of hydrogen.

Abstract: The interaction of triphenylphosphine, -arsine and -stibine with hydrated ruthenium trichloride in methanol leads to a variety of complexes such as [RuCl2(PPh3)4], [RuCl2(PPh3)3], [RuCl3(PPh3)2CH3OH], [RuCl3(AsPh3)2CH3OH] and [RuCl2(SbPh3)3]. The corresponding bromo complexes are also described. New mono and dicarbonyl complexes of ruthenium (II) and (III) have also been prepared by the interaction of Ph3P, Ph3As, Ph3Sb, pyridine etc., with a carbonyl-containing solution. Complexes of type cis and trans-[RuCl2(CO)2L2], [RuCl2(CO)L3] and [pyH][RuCl4COpy] are described.

Abstract: IT has been shown1,2 from an examination of the polarographic behaviour of some Rh(III)-arsine and phosphine complexes in dimethylformamide (DMF) as solvent that these complexes undergo reaction with the solvent. To elucidate this reaction and to identify the reaction product, an investigation has been undertaken, the results of which are reported here.

Abstract: Resume La reaction de transfert catalytique d'hydrogene etudiee avec le di- O -isopropylidene-2,3,4;5-D-mannofuranose comme donneur et RuH 2 (PPh 3 ) 4 comme catalyseur est etendue a d'autres sucres reducteurs pyranosiques et furanosiques possedant d'autres groupes hydroxyles libres. Le transfert est regiospecifique et la transformation en lactones s'effectue avec des rendements eleves en presence d'un exces d'accepteur. Cette reaction s'accompagne en absence ou en defaut d'accepteurs d'un processus d'oxydoreduction qui transforme le sucre reducteur en un melange de lactone et d'itol.