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A facile synthetic route for benzimidazoles, benzothiazoles and benzoxazoles comprising the reaction of corresponding o-phenylenediamine, o-aminothiophenol and o-aminophenol with various aldehydes using silica supported nano-copper (II) oxide as a catalyst has been described. The catalyst exhibited a clean reaction profile with excellent yields in a short reaction time. The catalyst can be recycled effectively after use.

An efficient cross coupling amination of arene with azodicarboxylate to afford hydrazides catalysed by ruthenium chloride has been demonstrated. The catalyst was found to be effective across a spectrum of arenes with a variety of functional groups. The yields are found to be modest to low depending on the type of substrates. The catalyst can be recycled in ligand free conditions to afford the cross coupling reaction.

We describe a green and efficient procedure for the hydroacylation of aldehydes with diisopropyl azodicarboxylate, using CuO nanoparticles supported on silica (CuO-np/SiO2) as a catalyst, in good t...

Complexes [Ru2O(O2CR)2(1-MeIm)6](ClO4)2 (1a−c), [Ru2O(O2CR)2(ImH)6](ClO4)2 (2a,b), and [Ru2O(O2CR)2(4-MeImH)6](ClO4)2 (3a,b) with a (μ-oxo)bis(μ-carboxylato)diruthenium(III) core have been prepared by reacting Ru2Cl(O2CR)4 with the corresponding imidazole base, viz. 1-methylimidazole (1-MeIm), imidazole (ImH), and 4-methylimidazole (4-MeImH) in methanol, followed by treatment with NaClO4 in water (R: Me, a; C6H4-p-OMe, b; C6H4-p-Me, c). Diruthenium(III,IV) complexes [Ru2O(O2CR)2(1-MeIm)6](ClO4)3 (R: Me, 4a; C6H4-p-OMe, 4b; C6H4-p-Me, 4c) have been prepared by one-electron oxidation of 1 in MeCN with K2S2O8 in water. Complexes 1a, 2a·3H2O, and 4a·1.5H2O have been structurally characterized. Crystal data for the complexes are as follows: 1a, orthorhombic, P212121, a = 7.659(3) A, b = 22.366(3) A, c = 23.688(2) A, V = 4058(2) A3, Z = 4, R = 0.0475, and Rw = 0.0467 for 2669 reflections with Fo > 2σ(Fo); 2a·3H2O, triclinic, P1, a = 13.735(3) A, b = 14.428(4) A, c = 20.515(8) A, α = 87.13(3)°, β = 87.61(3)°...

Three cationic surfactants with covalently attached anthraquinone moieties at the headgroup region, 1-3, were synthesized. The single chain surfactant, N,N-dimethyl-N-octadecyl-N-((9,10-dihydro-9,10-dioxoanthracen-2-yl)methyl)ammonium bromide, 1, upon comicellization with cetyltrimethylammonium bromide (CTAB) in water gave micellar aggregates with anthraquinone residues attached at the exposed aqueous interfaces. The two double chain amphiphiles, N,N-dioctadecyl-N-methyl-N-((9,10-dihydr-9,-10-dioxoanthracen-2-yl)methyl)ammonium bromide, 2, and N,N-dimethyl-N-(1,2-bis(palmitoyloxy)propanyl)-N-((9,10-dihydro-9,10-dioxoanthracen-2-yl)methyl)ammonium bromide, 3, however, on suspension with either dioctadecyldimethylammonium bromide (DODAB) or alone in aqueous media gave vesicular assemblies with anthraquinone residues attached both at the inner and at the outer aqueous vesicular surfaces. Holomicellar I or comicellar 1/CTAB deposited on to the glassy carbon electrode surface during cyclic voltammometric studies. Above their critical temperatures for the gel to liquid-crystalline-like phase transitions, the vesicular systems also formed electroactive layers on glassy carbon electrodes. In this paper, we present in detail various electrochemical aspects concerning these anthraquinone aggregates and the role of introduction of electrochemically inert cosurfactants in the formation of such electroactive deposits.

It is demonstrated that the condensations proceed with high efficiency in a short reaction time.

An efficient cross coupling amination of arene with azodicarboxylate to afford hydrazides catalysed by ruthenium chloride has been demonstrated. The catalyst was found to be effective across a spectrum of arenes with a variety of functional groups. The yields are found to be modest to low depending on the type of substrates. The catalyst can be recycled in ligand free conditions to afford the cross coupling reaction.

A wide range of aldehydes (I), including aromatic and aliphatic derivatives, is applied in the title reaction.

Edge-sharing bioctahedral (ESBO) complexes [Ru-2(OMe)(O2CC6H4-p-X)3(1-MeIm)(4)](ClO4)2 (X = OMe (1a), Me (1b)) and [Ru-2(O2CC6H4-P-X)(4)(1-MeIm)(4)](ClO4)(2) (X = OMe (2a), Me (2b)) are prepared by reacting Ru2Cl(O(2)CR)(4) with 1-methylimidazole (1-MeIm) in methanol followed by treatment with NaClO4. Complex 2a and the PF6- salt (1a') of 1a have been structurally characterized. Crystal data for 1a.1.5MeCN. 0.5Et(2)O: triclinic, P (1) over bar, a = 13.125(2) Angstrom, b = 15.529(3) Angstrom, c 17.314(5) Angstrom, a; 67.03(2)degrees, beta 68.05(2)degrees, gamma = 81.38(1)degrees, V 3014(1) Angstrom(3), Z = 2. Crystal data for 2a: triclinic, P (1) over bar, a 8.950(1) Angstrom, b = 12.089(3) Angstrom, c = 13.735(3) Angstrom, alpha 81.09(2)degrees, beta = 72.27(1)degrees, gamma = 83.15(2)degrees, V = 1394(1) Angstrom(3), Z = 1. The complexes consist of a diruthenium(III) unit held by two monoatomic and two three-atom bridging ligands. The 1-MeIm ligands are at the terminal sites of the [Ru-2(mu-L)(eta(1):mu-O(2)CR)(eta(1):eta(1):mu-O(2)CR)(2)](2+) core having a Ru-Ru single bond (L = OMe or eta(1)-O(2)CR). The Ru-Ru distance and the Ru-O-Ru angle in the core of 1a' and 2a are 2.49 Angstrom and similar to 76 degrees. The complexes undergo one-electron oxidation and reduction processes in MeCN-0.1 M TBAP to form mixed-valence diruthenium species with Ru-Ru bonds of orders 1.5 and 0.5, respectively.

An air-stable and water-soluble diastereomeric half-sandwich ruthenium(I1) complex, [Ru(η-MeC 6 H 4 Pr i -p)(H 2 O)-(L ∗ )](ClO 4 ) (l), has been isolated and structurally characterized [HL ∗ = (27)-(α-methylbenzyl)salicylaldimine, 2-HOC 6 H 4 CH=NCHMePh]. Complex 1, C 25 H 30 NO 6 ClRu, crystallizes in the noncentric triclinic space group P1 with a=9.885(1)A, b=10.185(1)A, c=14.187(2)A, α=110.32(1)°, β=102.17(1)°, A=102.41(1)°, V=1243( 1) A 3 , and Z=2. The X-ray structure shows the presence of two diastereomers in a 1:l ratio having R Ruν S C and S Ruν S C configurations. The Ru-OH 2 bond distances are considerably long, and the values for R Ru -1 and S Ru -1isomers are 2.119(5) and 2.203(5) A, respectively. The aqua complex (1) exists as a single diastereomer in solution, and it forms stable adducts with P-, N-, and halide-donor ligands. The stereochemical changes associated with adduct-forming reactions follow an inversion order: PPh 3 »P(OMe) 3 > pyridine bases»halides (I, Br, Cl)>H 2 O.

Arene ruthenium(II) Schiff base complexes of formulations [(η -p-cymene)RuCl(C5H4N-2-CH=NC6H4-p-X)](ClO4) (1) and [(η6-p-cymene)RuCl(O-o-C6H4CH=NC6H4-p-X)] (2) (X = H, Me, OMe, NO2, Cl) were prepared by reacting [(η6-p-cymene)RuCl2]2 with corresponding pyridine-2-carboxaldimines and sodium salts of salicylaldimines in dry THF, respectively. Complex 1 is isolated as a perchlorate salt. The molecular structure of [(η6-p-cymene)RuCl(C5H4 N-2-CH=NC6H4-p-Me)]Cl·C6H6·H2O has been determined by X-ray crystallography. The complex contains an η6-p-cymene group, a chloride and a bidentate chelating Schiff base ligand.

Reaction of [(eta-6-p-cymene)RuCl(L star)] with AgClO4 in Me2CO gives a perchlorate complex which on subsequent treatment with PPh3, gamma-picoline or Cl- yields adducts showing that there can be retention as well as inversion of configuration at the metal centre. The (R)Ru,(S)C absolute configurations of the chiral centres in the triphenylphosphine adduct have been established by an X-ray diffraction study [HL star, (S)-alpha-methylbenzylsalicylaldimine]. The CD spectral study reveals that there is an inversion of configuration during formation of the PPh3 adduct.

Complexes of the formulae [(-Cp)Ru(PPh3)(2-PPH)]Cl and [(Cp)Ru(PPh3) (py)(1-PPH)]Cl were prepared by reacting pyridyl-2-phenylhydrazone [PPH, C5H4N-2-CH=NNHPh] with (-Cp)Ru(PPh3)2Cl and (-Cp)Ru(PPh3)(py)Cl, respectively. In these complexes the PPH ligand displays bidentate chelating and unidentate modes of bonding. The molecular structure of [(-Cp)Ru(PPh3)(2-PPH)](ClO4)·CH2Cl2 was determined by X-ray crystallography. In this complex the metal is bonded to the N-pyridyl and N-imine atoms of the chelating ligand. 1H NMR spectral data suggests that PPH is bonded to ruthenium through the pyridine moiety of the PPH ligand in [(η-Cp)Ru(PPh3)(py)(η1-PPH)]Cl.

A potent superoxide dismutase mimic, MnII(HL)2[H2L = 2,6-bis(benzimidazol-2-yl)pyridine] has been synthesised and characterised by its crystal structure determination and EPR spectroscopy.

Diastereomers (SRu,Sc)-1a and (RRu,Sc)-1b, in a ratio of 85: 15 and formulated as [Ru(η-MeC6H4Pri-p)Cl(L*)], have been prepared by treating [{Ru(η-MeC6H4Pri-p)Cl2}2] with the sodium salt of (S)-α-methylbenzylsalicylaldimine (HL*) in tetrahydrofuran at –70 °C. The reaction of 1(1a+1b) with AgClO4 in acetone followed by an addition of PPh3 or 4-methylpyridine (4Me-py) leads to the formation of adducts [Ru(η-MeC6H4Pri-p)(PPh3)(L*)]ClO42[(SRu,Sc)2a, (FRu,Sc)2b] and [Ru(η-MeC6H4Pri-p)(4Me-py)(L*)]ClO43[(SRu,Sc)3a, (RRu,Sc)3b] in the diastereomeric ratios (SRu,Sc) : (RRu,Sc) of 2 : 98 and 76 : 24, respectively. Complex 1 crystallises with equal numbers of 1a and 1b molecules in an asymmetric unit of monoclinic space group P21 with a= 10.854(1), b= 17.090(1), c= 12.808(4)A, β= 110.51(1)°, and Z= 4. The structure was refined to R= 0.0552 and R′= 0.0530 with 2893 reflections having I[gt-or-equal] 1.5σ(I). The absolute configurations of the chiral centres in the optically pure single crystal of the PPh3 adduct have been obtained from an X-ray study. Crystals of formulation [Ru(η-MeC6H4Pri-p)-(PPh3)(L*)]2[ClO4][PF6]·1.5 CHCl3, obtained in presence of both ClO4 and PF6 anions, belong to the non-centric triclinic space group P1 with a= 10.852(2), b= 14.028(1), c= 15.950(2)A, α= 91.51(1), β= 105.97(1), γ= 106.11(1)°, and Z= 2. The final residuals were R= 0.0713, R′= 0.0752 with 7283 reflections having I[gt-or-equal] 2.5σ(I). The crystal structures of 1a,1b, and the PPh3 adduct (2b,2b′) consist of a ruthenium(II) centre bonded to a η-p-cymene, a bidentate chelating Schiff base, and a unidentate ligand (Cl or PPh3). The chirooptical properties of the complexes have been studied using 1H NMR and CD spectral data. The presence of a low-energy barrier for the intermediate involved in these reactions, showing both retention as well as inversion of the metal configuration, is discussed.

On montre que les alcools contenant 2 atomes H s'oxydent en aldehyde correspondant en presence d'un intermediaire actif qui serait une espece di-Ru contenant PPh 3 dans sa sphere de coordination. Formation quantitative de Ru 2 O(PPh 3 ) 2 (O 2 CR) 4

On montre que les alcools contenant 2 atomes H s'oxydent en aldehyde correspondant en presence d'un intermediaire actif qui serait une espece di-Ru contenant PPh 3 dans sa sphere de coordination. Formation quantitative de Ru 2 O(PPh 3 ) 2 (O 2 CR) 4