Heptaphosphide cluster anions bearing group 14 element amide functionalities

Reactions of the protonated heptaphosphide dianion, [HP7]2−, with one equivalent of E[N(SiMe3)2]2(E = Ge, Sn, Pb) give rise to novel derivatized cluster anions [P7EN(SiMe3)2]2−(E = Ge (1), Sn (2) and Pb (3)).1readily decomposes in solution at room temperature to afford the dimeric product [(P7Ge)2N(SiMe3)2]3−(4).

Attenuation of Carcinogenesis and the Mechanism Underlying by the Influence of Indole-3-carbinol and Its Metabolite 3,3′-Diindolylmethane: A Therapeutic Marvel

Rising evidence provides credible support towards the potential role of bioactive products derived from cruciferous vegetables such as broccoli, cauliflower, kale, cabbage, brussels sprouts, turnips, kohlrabi, bok choy, and radishes. Many epidemiological studies point out thatBrassicavegetable protects humans against cancer since they are rich sources of glucosinolates in addition to possessing a high content of flavonoids, vitamins, and mineral nutrients. Indole-3-carbinol (I3C) belongs to the class of compounds called indole glucosinolate, obtained from cruciferous vegetables, and is well-known for tits anticancer properties. In particular, I3C and its dimeric product, 3,3′-diindolylmethane (DIM), have been generally investigated for their value against a number of human cancersin vitroas well asin vivo. This paper reviews an in-depth study of the anticancer activity and the miscellaneous mechanisms underlying the anticarcinogenicity thereby broadening its therapeutic marvel.

Treatment of Tetramethylpyrazole and 3,5-Diphenylpyrazole with Dialkylaluminum Hydrides - Hydroalumination versus Deprotonation

Treatment of tetramethylpyrazole, N2C3Me4, with equimolar quantities of di(tert-butyl)aluminum hydride leads to the addition of an Al-H bond to one of the C=N double bonds. The dimeric product (1) contains a central six-membered Al2N4 ring in which two tBu2Al+ units are bridging two N2C3 heterocycles. In the zwitterionic, non-centrosymmetric compound one aluminum atom is coordinated by two imino nitrogen atoms, while the second one is bonded to two amide nitrogen atoms. No double hydroalumination occurs upon treatment of tetramethylpyrazole with two equivalents of the hydride. Instead, an adduct (2) of the monomeric hydroalumination product with di(tert-butyl)aluminum hydride was isolated in which the two aluminum atoms are connected by a 3c-2e Al-H-Al bond. A unique trinuclear compound (3) is obtained upon reaction of tetramethylpyrazole with an excess of the sterically less shielded diethylaluminum hydride. It contains two different N2C3 heterocycles: One still contains a C=N double bond similar to that in compounds 1 and 2, while the second one is completely reduced by double hydroalumination to give a saturated heterocycle. The two rings are bridged by three AlEt2 groups. Deprotonation results upon treatment of 3,5-diphenylpyrazole, N2C3H2(C6H5)2, with di(tert-butyl)aluminum hydride.

New Method to Follow the Dimerisation Reaction Occuring during Oxidation of 4-Ethylguaiacol

Summary 4-Ethylguaiacol is a phenolic model compound used to study the oxidation of lignin. A new method was developed to determine 4,4′-diethyl-6,6′-biguaiacol, an unwanted side-product, in the oxidation of 4-ethylguaiacol. The sample is extracted with ethyl acetate to separate 4,4′-diethyl-6,6′-biguaiacol from the water-soluble oxidation catalyst. No other treatment is required before analysis with a standard UV-Vis spectrophotometer. The spectrophotometer is calibrated to measure concentrations of 4,4′-diethyl-6,6′-biguaiacol up to 0.3 mM. With the new method, the concentrations of 4,4′-diethyl-6,6′-biguaiacol can be reliably determined over a wide alkaline pH range. The performance of the method was demonstrated in experiments investigating the formation of 4,4′-diethyl-6,6′-biguaiacol in the autoxidation and cobalt-sulphosalen catalysed oxidation of 4-ethylguaiacol. In the conditions of the studies (1 bar oxygen pressure and 50°C), a low (0.01 mM) concentration of Co-sulphosalen clearly increased the total conversion of 4-ethylguaiacol. However, relative to autoxidation, the conversions achieved in the presence of the catalyst were just as sensitive to pH, and the yields of the undesired dimeric product, 4,4′-diethyl-6,6′-biguaiacol, were higher.

Gold Coordination by a Tertiary Phosphine with Three Thioether Functions

The reaction of tris(phenylthiomethyl)phosphine with equimolecular amounts of [AuPPh3]+[BF4]- affords the complex (tris(phenylthiomethyl)phosphine)(triphenylphosphine)- gold(I) tetrafluoroborate 1 in good yield. The X-ray diffraction analysis of this product shows an unusual conformation with the three ChLSPh arms of the phosphine folded back towards the metal atom shielding the P-Au-P′ unit. The reaction of the same substrate with Bis(tetrahydrothiophene)gold(I) perchlorate in a 1:1 molar ratio leads to the displacement of both weakly coordinated tht ligands, and a dimeric product [AuP(CH2SPh)3]2(ClO4)2 2 is obtained.