The reaction of sodium diselenide with optically active alkyl tosylates or chlorides is found to be a useful method for the synthesis of optically active dialkyl diselenides. Optically active monoterpene diselenides derived from menthane, carane, pinane, and bornane systems have been obtained. The influence of the terpene fragment of the obtained diselenides on the diastereomeric excess of the methoxyselenylation products has been investigated. The best result for methoxyselenylation was observed for (–)‐diisopinocamphyl diselenide. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Novel chiral N-heterocyclic carbenes derived from (−)-β-pinene have been synthesized and used as efficient catalysts for the intramolecular Stetter reaction. Mono-, di-, and trisubstituted 4-chromanone derivatives have been obtained almost quantitatively and with high enantioselectivity up to 99:1 er.

In the present work, gold electrodes were modified using a redox-active layer based on dipyrromethene complexes with Cu(II) or Co(II) and a dipodal anion receptor functionalized with dipyrromethene. These modified gold electrodes were then applied for the electrochemical detection of anions (Cl, SO, and Br) in a highly diluted water solution (in the picomolar range). The results showed that both systems, incorporating Cu(II) as well as Co(II) redox centers, exhibited highest sensitivity toward Cl. The selectivity sequence found for both systems was Cl > SO > Br. The high selectivity of Cl anions can be attributed to the higher binding constant of Cl with the anion receptor and the stronger electronic effect between the central metal and anion in the complex. The detection limit for the determination of Cl was found at the 1.0 pM level for both sensing systems. The electrodes based on Co(II) redox centers displayed better selectivity toward Cl anion detection than those based on Cu(II) centers which can be attributed to the stronger electronic interaction between the receptor-target anion complex and the Co(II)/Co(III) redox centers in comparison to the Cu(II)/Cu(I) system. Applicability of gold electrodes modified with DPM-Co(II)-DPM-AR for the electrochemical determination of Cl anions was demonstrated using the artificial matrix mimicking human serum.

In many settings, molecular testing is needed but unavailable due to complexity and cost. Simple, rapid, and specific DNA detection technologies would provide important alternatives to existing detection methods. Here we report a novel, rapid nucleic acid detection method based on the accelerated photobleaching of the light-sensitive cyanine dye, 3,3′-diethylthiacarbocyanine iodide (DiSC 2 (3) I − ), in the presence of a target genomic DNA and a complementary peptide nucleic acid (PNA) probe. On the basis of the UV-vis, circular dichroism, and fluorescence spectra of DiSC 2 (3) with PNA-DNA oligomer duplexes and on characterization of a product of photolysis of DiSC 2 (3) I − , a possible reaction mechanism is proposed. We propose that (1) a novel complex forms between dye, PNA, and DNA, (2) this complex functions as a photosensitizer producing 1 O 2 , and (3) the 1 O 2 produced promotes photobleaching of dye molecules in the mixture. Similar cyanine dyes (DiSC 3 (3), DiSC 4 (3), DiSC 5 (3), and DiSC py (3)) interact with preformed PNA-DNA oligomer duplexes but do not demonstrate an equivalent accelerated photobleaching effect in the presence of PNA and target genomic DNA. The feasibility of developing molecular diagnostic assays based on the accelerated photobleaching (the smartDNA assay) that results from the novel complex formed between DiSC 2 (3) and PNA-DNA is under way.Photobleaching of cyanine dyes is usually seen as an undesirable characteristic which hampers their use in nucleic acid detection. However, we have discovered that in the presence of a target specific peptide nucleic acid (PNA) oligomer probe, the rate of 3,3′-diethylthiacarbocyanine iodide (DiSC 2 (3)) photobleaching is directly related to the amount of target DNA present. We call this type of reaction "smartDNA" and this rapid color loss can be used as a sensitive indicator for the presence of a specific DNA sequence.PNAs, which are used in the current assay as hybridization probes, are oligonucleotide analogues where the negatively charged phosphoribose backbone has been replaced with a neutral N-(2-aminoethyl) glycine group. 1,2 The absence of the negatively charged backbone gives PNAs unique physiochemical properties for binding to nucleic acid targets. PNAs rapidly *Corresponding

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A catalytic asymmetric intramolecular crossed-benzoin reaction for the synthesis of chromanones by novel camphor-derived N-heterocyclic carbenes is described. The corresponding chromanones bearing quaternary stereogenic centers were isolated in high yields with high to excellent enantioselectivity.

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