Synthesis of 2,3‐Diaryl‐3H‐pyrrolo[2,3‐c]pyridin‐3‐ol Derivatives by the Reaction of Aryl(3‐isocyanopyridin‐4‐yl)methanones with Aryl Grignard Reagents

The reaction of aryl(3‐isocyanopyridin‐4‐yl)methanones 1 , easily prepared from commercially available pyridin‐3‐amine, with aryl Grignard reagents gave, after aqueous workup, 2,3‐diaryl‐3H‐pyrrolo[2,3‐c]pyridin‐3‐ols 2 . These rather unstable alcohols were O‐acylated with Ac₂O in pyridine in the presence of a catalytic amount of 4‐(dimethylamino)pyridine (DMAP) to afford the corresponding 2,3‐diaryl‐3H‐pyrrolo[2,3‐c]pyridin‐3‐yl acetates 3 in relatively good yields.     

Synthesis of 9,9‐Disubstituted 9H‐Pyrrolo[1,2‐a]indoles by Hydriodic Acid‐Catalyzed Cyclization of 1‐[2‐(1‐Aryl(or methyl)ethenyl)phenyl]‐1H‐pyrroles

A novel method is reported for the synthesis of 9,9‐disubstituted 9H‐pyrrolo[1,2‐a]indoles. Cyclization of 1‐[2‐(1‐aryl(or methyl)ethenyl)phenyl]‐1H‐pyrroles, which can be easily prepared from 2‐(1‐aryl(or methyl)ethenyl)anilines, proceeds smoothly, in general, at 0° in the presence of a catalytic (or an equimolar) amount of HI in MeCN to provide the desired products.     

Dioxygen activation and substrate oxygenation by a p-nitrothiophenolatonickel complex: unique effects of an acetonitrile solvent and the p-nitro group of the ligand

The nickel(II) complex [Ni(Tp(Me2)) (SC(6)H(4)NO(2))] [1a; Tp(Me2) = hydrotris(3,5-dimethylpyrazol-1-yl)borate] reacts with O(2) to form the ligand oxygenation product ArSO(2)(-) in MeCN, and also 1a catalyzes the oxygenation of external substrates such as triphenylphosphine. The reactivity may correlate to the unique quinoid-like resonance structure of the thiophenolate ligand. The structure is stabilized by a p-nitro group and induced by coordination of MeCN.     

In vivo participation of artificial porphyrins in electron-transport chains: electrochemical and spectroscopic analyses of microbial metabolism

The effects of artificial porphyrins on the electron-transport chains of living microbes were investigated. The participation of porphyrins in the microbial electron-transport chains was demonstrated by spectroscopic and current-generation measurements. Large enhancement of the microbial current generation was accomplished by adding a cationic water-soluble manganese porphyrin as an electron mediator.     

Synthesis and properties of oxo-carboxylato- and dioxo-bridged diosmium complexes of tris(2-pyridylmethyl)amine

A series of oxo-bridged diosmium complexes with tpa ligand (tpa = tris(2-pyridylmethyl)amine) are synthesized. The hydrolytic reaction of the mononuclear osmium complex [Os(III)Cl(2)(tpa)]PF(6) in aqueous solution containing a sodium carboxylate yields a μ-oxo-μ-carboxylato-diosmium(III) complex, [Os(III)(2)(μ-O)(μ-RCOO)(tpa)(2)](PF(6))(3) (R = C(3)H(7) (1), CH(3) (2), or C(6)H(5) (3)). One-electron oxidation of 1 with (NH(4))(2)Ce(IV)(NO(3))(6) gives a mixed-valent [Os(III)Os(IV)(μ-O)(μ-C(3)H(7)COO)(tpa)(2)](PF(6))(4) complex (4). A mixed-valent di-μ-oxo-diosmium complex, [Os(III)Os(IV)(μ-O)(2)(tpa)(2)](PF(6))(3) (5), is also synthesized from 1 in an aerobic alkaline solution (pH 13.5). All the complexes exhibit strong absorption bands in a visible-near-infrared region based on interactions of the osmium dπ and oxygen pπ orbitals of the Os-O-Os moiety. The X-ray crystallographic analysis of 1, 3, and 4 shows that the osmium centers take a pseudo-octahedral geometry in the μ-oxo-μ-carboxylato-diosmium core. The mixed-valent osmium(III)osmium(IV) complex 4 has a shorter osmium-oxo bond and a larger osmium-oxo-osmium angle as compared with those of the diosmium(III) complex 1 having the same bridging carboxylate. Crystal structure of 5 reveals that the two osmium ions are bridged by two oxo groups to give an Os(2)(μ-O)(2) core with the significantly short osmium-osmium distance (2.51784(7) ?), which is indicative of a direct osmium-osmium bond formation with the bond order of 1.5 (σ(2)π(2)δ(2)δ*(2)π*(1) configuration). In the electrochemical studies, the μ-oxo-μ-carboxylato-diosmium(III) complexes exhibit two reversible Os(III)Os(III)/Os(III)Os(IV) and Os(III)Os(IV)/Os(IV)Os(IV) oxidation couples and one irreversible redox wave for the Os(III)Os(III)/Os(II)Os(III) couple in CH(3)CN. The irreversible reductive process becomes reversible in CH(3)CN/H(2)O (1:1 Britton-Robinson buffer; pH 5-11), where the {1H(+)/2e(-)} transfer process is indicated by the plot of the redox potentials against the pH values of the solution of 1. Thus, the μ-oxo-μ-butyrato-diosmium(III) center undergoes proton-coupled electron transfer to yield a μ-hydroxo-μ-butyrato-diosmisum(II) species. The di(μ-oxo) complex 5 exhibits one reversible Os(III)Os(IV)/Os(IV)Os(IV) oxidation process and one reversible Os(III)Os(IV)/Os(III)Os(III) reduction process in CH(3)CN. The comproportionation constants K(com) of the Os(III)Os(IV) states for the present diosmium complexes are on the order of 10(19). The values are significantly larger when compared with those of similar oxo-bridged dimetal complexes of ruthenium and rhenium.     

Towards clinical proteomics analysis

To understand accurate protein dynamics, a highly reproducible proteomics analytical method is required. The acquired thus knowledge will lead to the diagnosis, treatment and protection against diseases. This review deals with proteomics analysis from a view of sample pre-treatment, sensitivity and reproducibility of the methods, including two-dimensional polyacrylamide gel electrophoresis (2D-PAGE), liquid chromatography-tandem mass spectrometry (LC-MS/MS). and fluorogenic derivatization (FD)-LC-MS/MS.     

Enantiomeric separation of D,L-tryptophan and D,L-kynurenine by HPLC using pre-column fluorescence derivatization with R(-)-DBD-PyNCS

The enantiomeric separation of d ,l ‐tryptophan (Trp) and d ,l ‐kynurenine (KYN) was investigated by high‐performance liquid chromatography using pre‐column fluorescence derivatization with a chiral fluorescent labeling reagent, R(−)‐4‐(3‐isothiocyanatopyrrolidin‐1‐yl)‐7‐ (N,N‐dimethylaminosulfonyl)‐2,1,3‐benzoxadiazole [R(−)‐DBD‐PyNCS]. Using an octadecylsilica column, namely, an Inertsil ODS‐3 column (250 × 2.0 mm; i.d., 3 µm), four fluorescence peaks of D‐ and l ‐Trp as well as d ‐ and l ‐KYN derivatized with R(−)‐DBD‐PyNCS were clearly observed, and their chemical structures were confirmed by HPLC–time‐of‐flight–mass spectrometry. Simultaneous separation was achieved under the mobile phase condition of 1.5% acetic acid in H₂O–CH₃CN (60:40), and the separation factors of d ,l ‐Trp and d ,l ‐KYN derivatized with R(−)‐DBD‐PyNCS were 1.22 and 1.19, respectively. Fluorescence detection was carried out by setting the emission wavelength at 565 nm, and the excitation wavelength at 440 nm, and the detection limits were approximately 0.3–0.5 pmol (signal‐to‐noise ratio of 3). Copyright © 2010 John Wiley & Sons, Ltd.     

Facile fullerene modification: FeCl3-mediated quantitative conversion of C60 to polyarylated fullerenes containing pentaaryl(chloro)[60]fullerenes

A facile, one-step reaction using inexpensive reagents has been developed for functionalization of [60]fullerene, where the reaction of C(60) with FeCl(3) in chlorobenzene proceeded at 25 °C with 100% conversion, yielding a mixture of polyarylated products containing pentaaryl(chloro)[60]fullerene, C(60)(C(6)H(4)Cl)(5)Cl (up to 29%) and other polyarylated fullerenes (number of aryl groups is in a range from 5 to 10).     

Synthesis of a head-to-tail-type cyclodextrin-based insulated molecular wire

We developed a new method for synthesizing an organic-soluble insulated molecular wire (IMW) using permethylated cyclodextrin (PMCD). The IMW obtained using this method is highly soluble in a variety of organic solvents and has a high covering ratio, regioregularity, rigidity, photoluminescence efficiency, and interchain hole mobility.