Volume 70, Issue 8

By using K 4 [Mo(CN) 8 ] and [Ni(L)(H 2 O) 2 ][ClO 4 ] 2 as reagents (L = 2,12-dimethyl-3,7,11,17-tetraazabicyclo [11.3.1]heptadeca-1(17),13,15-triene), a new cyanide-bridged Mo–Ni complex containing the building blocks [Ni(H 2 O)(L)] 2+ and [Ni(L)] 2+ bridged by [Mo(CN) 8 ] 4− units has been obtained. The complex with the formula {[Ni(H 2 O)(L)][Ni(L)][Mo(CN) 8 ]} 6  · 36H 2 O · 2CH 3 OH ( 1 ) was characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. The structure determination reveals an octadecanuclear cluster in the form of a 36-membered macrocycle, in which the largest intramolecular W···W and Ni···Ni distances are 16.5 and 14.4 Å, respectively, indicating that complex 1 is a nanosized molecular wheel. Investigation of its magnetic properties has shown weak antiferromagnetic coupling between the adjacent Ni(II) ions bridged by the diamagnetic [Mo(CN) 8 ] 4− ions.

A novel γ -lactone derivative, turranin G ( 1 ), and five known compounds were isolated from the twigs of Turraea pubescens. The structures of 1 – 6 were determined by means of spectroscopic analysis. The biogenetic pathway of compound 1 was proposed. Compound 2 exhibited inhibitory activity against lipopolysaccharide-induced nitric oxide in RAW264.7 cells with an IC 50 value of 18.8 μ m .

Treatment of (NMe 4 ) 2 [Mo 2 O 2 S 6 ] with Ag(PPh 3 ) 3 I in the presence of NaOEt in DMF/EtOH resulted in the formation of a novel Mo VI /Mo V polyoxothiomolybdate cluster compound [(μ-I){Ag(PPh 3 ) 3 } 2 ] 2 [Mo 8 O 8 (μ-OH) 2 (μ-OEt) 6 (μ-S) 8 (μ 3 -O) 4 {Mo(DMF) 2 }] · 2EtOH. The cyclic cluster polyanion consists of an octamer {Mo 8 O 8 (μ-OH) 2 (μ-OEt) 6 (μ-S) 8 (μ 3 -O) 4 } that encapsulates a central {Mo VI (DMF) 2 (μ 3 -O) 4 } octahedron.

Silver(I) complexes of thioureas and thiocyanate, [(Tu)AgSCN], [(Metu)AgSCN], [(Dmtu)AgSCN], [(Tmtu)(AgSCN) 1.5 ], [(Imt)AgSCN], and [(Diaz)AgSCN] (where Tu = thiourea, Metu = N -methylthiourea, Dmtu = N , N ′-dimethylthiourea, Tmtu = N , N , N ′, N ′-tetramethylthiourea, Imt = 1,3-imidazolidine-2-thione, and Diaz = 1,3-diazinane-2-thione), have been prepared and characterized by elemental analysis, IR and NMR spectroscopy, and thermal analysis. The crystal structure of one of them, [(Diaz)Ag(SCN)] ( 1 ), was determined by X-ray crystallography. The crystal structure of 1 shows that the complex exists in the form of a chain-like polymer comprising [Ag( μ 2 -Diaz)( μ 2 -SCN)] units. The silver atoms are bridged by μ 2 -thione sulfur atoms of Diaz and μ 2 -thiocyanate sulfur atoms. Thereby each silver atom adopts a distorted tetrahedral coordination environment comprising four sulfur atoms, two from thione and two from thiocyanate ligands. An upfield shift in the >C=S resonance of thiones in 13 C NMR and a downfield shift in the N–H resonance in 1 H NMR are consistent with the sulfur coordination to silver(I). The appearance of a band around 2100 cm –1 in the IR and a resonance around 125 ppm in the 13 C NMR spectrum indicates the binding of thiocyanate to silver(I).

A hybrid compound, [Cu I 4 (bpmb) 4 ][PW VI 11 W V O 40 ] ( 1 ) (bpmb = 1,4-bis(pyrazol-1-ylmethyl)benzene), has been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction analysis, infrared spectroscopy, elemental analyses and powder X-ray diffraction. In compound 1 crown-like [Cu 4 (bpmb) 4 ] 4+ macrocycles templated by Keggin-type [PW VI 11 W V O 40 ] 4− polyanions (abbreviated PW 12 ) exist. Supramolecular layers are formed by intermolecular hydrogen bonding interactions of discrete crown-like [Cu 4 (bpmb) 4 ] 4+ macrocycles and [PW VI 11 W V O 40 ] 4− polyanions. The electrochemical and luminescence properties of compound 1 were investigated.

Four indolizine derivatives were obtained via 1,3-dipolar cycloaddition reaction of 1-(2′-benzimidazolylmethyl)pyridinium ylide with various electron-deficient alkynes. The reaction of this pyridinium N -ylide with dimethyl maleate gave an unexpected methyl 1-oxo-benzimidazo[1,2- a ]pyridine-3-carboxylate. The structures of all reported compounds have been examined by X-ray crystallography and NMR spectroscopy.

Zusammenfassung: Es wird vorgeschlagen, das Akronym „RIBIL“ für flüssige, reaktive, Iminiumsalz-basierte Verbindungen zu verwenden. Eine Zusammenstellung von strukturell unterschiedlichen RIBILs wird vorgestellt. Die Anwendung von RIBILs als Reaktionsmedium ist vorteilhaft, da sie bei geeigneter Wahl der Reaktanden eine besonders einfache Aufarbeitung erlaubt. Die Reaktion äquimolarer Mengen an aliphatischen Carbonsäuren und Alkoholen in N,N-Dimethyl-(hydroxymethylen)iminium-hydrogensulfat (DMF/H 2 SO 4 -Addukt) ( 20c ) führt zu Carbonsäureestern, die sich aus dem Reaktionsgemisch als zweite Phase abscheiden.

The dimerization of an α , β -unsaturated ketone led to a product that consists of a single diastereomer with all- trans configuration, as shown by an X-ray structure investigation. We postulate that the steric bulk of the 4-[2.2]paracyclophanyl substituent is responsible for the diastereoselectivity. The central cyclobutane ring is puckered, with a fold angle of 27.9(1)°. The cyclophane units show the usual distortions associated with the bridge strain.

Two new complexes, {[Cd(immb)I 2 ]·DMF} n ( 1 ) and {[Cd 3 (immb)(btc) 2 ]·H 2 O} n ( 2 ) (immb = 2-(1 H -imidazol- 1-methyl)-6-methyl-1 H -benzimidazole, btc = 1,2,3-benzenetricarboxylate, DMF = dimethyl formamide), have been synthesized and characterized. Single crystal X-ray diffraction shows that 1 exhibits a chain structure constructed by immb ligands bridging Cd(II) ions. In 2 , Cd(II) ions are linked by immb ligands with bridging mode and btc 3– anions with the μ 2 - η 2 : η 1 bonding pattern leading to a 2D structure. Luminescent properties have been investigated in the solid state at room temperature.

β -Hydroxyketones are versatile building blocks in organic synthesis, which can be conveniently synthesized from ketones and aldehydes by aldol reactions. Unfortunately, these reactions often suffer from dehydration of the initially formed β -hydroxyketones. Previously, tetrahedral 3,5-difluorophenylborate was shown to be an efficient and selective catalyst for this reaction. The present investigation concerns the catalytic performance of phenyl borates with different substitution patterns in the aldol reaction. It appears that the dehydration reaction can be suppressed by selecting substituents and substituent positions with reduced electron withdrawing effects on the borate function. Optimal suppression of the dehydration of β -hydroxyketones was obtained for compounds corresponding to phenylboronic acids with a p K a > 7. The reactions between benzaldehyde and butanone or 3-pentanone did not show diastereoselectivity, which suggests that the catalysts merely act as bases rather than as templates for the transition state of the aldol reaction. Sterically more demanding ketones were not converted.

A variety of novel 2-(substituted)- N -(4-oxo-2-phenylquinazolin-3(3 H )-yl)acetamides were synthesized by the reaction of 2-chloro- N -(4-oxo-2-phenylquinazolin-3(3 H )-yl)acetamide with various amines. The starting material, 2-chloro- N -(4-oxo-2-phenylquinazolin-3(3 H )-yl)acetamide, was synthesized from anthranilic acid by the multistep process. The title compounds were investigated for analgesic, anti-inflammatory, and ulcerogenic index activities. Among those, the compound 2-(ethylamino)- N -(4-oxo-2-phenylquinazolin-3(3 H )-yl)acetamide ( V9 ) showed most potent analgesic and anti-inflammatory activities of the series and it is moderately more potent compared to the reference standard diclofenac sodium. Interestingly, the test compounds showed only mild ulcerogenic potential compared to aspirin.

A new Cd(II) coordination polymer, [Cd(CNA)] n ( 1 ) (H 2 CNA = 3-(carboxymethoxy)-2-naphthoic acid), was hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. The crystals are monoclinic, space group P 2 1 / c with a = 16.9698(18), b = 7.8314(8), c = 8.9553(10) Å, β = 100.657(2)°, V = 1169.6(2) Å 3 , Z = 4, D calcd. = 2.03 g cm −3 , μ (Mo K α ) = 1.9 mm −1 , F (000) = 696 e, R = 0.0305, wR = 0.0784 for 172 refined parameters and 2285 data. Each CNA anion bridges three Cd(II) cations to give rise to a two-dimensional network structure. Topologically, if each CNA anion is regarded as a linker, and each Cd(II) atom considered as a 4-conencted node, the structure is simplified as a 4-connected (4,4) network. The solid state photoluminescent properties of the compound were also studied at room temperature.

A series of novel 3-aryl-6-adamantylmethyl-[1,2,4]triazolo[3,4- b ][1,3,4]thiadiazoles 6a–l were synthesized by a simple method with the aim of developing novel HIV non-nucleoside reverse transcriptase inhibitors. All the synthesized compounds were structurally confirmed by spectral analyses. The structure of 6a was unambiguously verified by X-ray structure determination. The synthesized compounds were evaluated for their anti-HIV activity and four analogs displayed moderate inhibitory activity with EC 50 values ranging from 10.10 to 12.40 μg mL –1 . Molecular docking of 6g with HIV-1 reverse transcriptase was studied to rationalize some structure-activity relationships (SARs).