Synthesis of novel fullerene amino acids and their multifullerene peptides

[60]-Fullerene functionalized amino acids with 4-6 methylene spacers from α-carbon to the nitrogen atom of fulleropyrolidine and corresponding multifullerene peptides have been synthesized.     

A stereocontrolled synthesis of C-4′ alkylated pyrimidine C-nucleosides

A general, stereocontrolled synthesis of pyrimidine $\text{C}$-nucleosides possessing an alkyl group at the C-1′ or C-4′ position is outlined.     

Template functions of particle monolayers on hydrophobic solid substrates

The template function of cationic particle monolayers bearing quaternary ammonium groups on their surfaces towards anionic colloids was investigated in this paper. Monodispersed cationic polymer particles having quaternary ammonium groups were self-organized on octadecylated glass plates through hydrophobic interaction. The morphology of the resulting particle monolayers was changed by tuning hydrophilic–hydrophobic balance of particles to fabricate aggregated type and dispersed type of particle monolayers. Gold and silver colloids were selectively deposited onto the particle monolayers through electrostatic interaction. The deposited gold and silver colloids on particle monolayers showed plasmon absorbance. Fluorescent silica colloids were also selectively deposited on particle monolayers to permit fluorescence labeling of the particle monolayers. Cationic particle monolayers fabricated on hydrophobic solid octadecylated were found to effectively work as templates for the deposition of above mentioned inorganic colloids.     

Synthesis and structure of 1-zirconacyclopent-3-yne complexes without substituents adjacent to the triple bond

Five-membered metallacyclic alkynes that have no substituents adjacent to the triple bond have been synthesized, isolated, and structurally characterized. Zirconocene dichlorides, Cp'2ZrCl2 (Cp' = C5H5, C5H4-t-Bu), reacted with 1,4-dichlorobut-2-yne in the presence of magnesium to give 1-zirconacyclopent-3-yne compounds (5 (a) Cp' = C5H5, (b) Cp' = C5H4-t-Bu) that have a -CH2CCCH2- moiety in good yields. They are stable enough to be isolated in a pure form, despite the absence of substituents. 5a reacted with an equimolar amount of Cp2Zr(but-1-ene)(PMe3) to produce a bimetallic complex in which the zirconacyclopentyne coordinates to the other zirconocene moiety as an alkyne.     

Comparison of separation behavior of benzodiazepines in packed capillary electrochromatography and open-tubular capillary electrochromatography

Packed column capillary electrochromatography (CEC), open-tubular CEC and microcolum liquid chromatography (LC) using a cholesteryl silica bonded phase have been studied to compare the retention behavior for benzodiazepines. It has been found that packed column CEC gives better resolution, faster analysis time than microcolumn LC for benzodiazepines maintaining similar selectivity except for some solutes which are charged species under the separation conditions. However, open-tubular CEC gave different selectivities to a larger extent for charged benzodiazepines from that which should be produced by the chromatographic properties of the cholesteryl silica phase. Charged species migration times are mainly influenced by electrophoretic mobility rather than the chromatographic interactions.     

Pyrimidines. 20. Novel reactions of 5-cyano-1,3-dimethyluracil. A simple synthesis of pyrido[2,3-d]pyrimidines

A reaction of 5-cyano-1,3-dimethyluracil (1, R = CN) with acetone in base afforded 1,3,7-trimethylpyrido-[2,3-d]pyrimidine-2,4(1H,3H)dione ( 9a ) in a moderate yield. From a reaction mixture of 1 (R = CN) with butanone, 1,3,6,7-tetramethyl- and 7-ethyl-1,3-dimethylpyrido[2,3-d]pyrimidine-2,4(1H,3H)-dione ( 9b and 9c , respectively) were isolated in low yields. When ethyl cyanoacetate or malononitrile was used in place of the ketone in the above reaction, 7-amino-6-ethoxycarbonyl- and 7-amino-6-cyano-1,3-dimethylpyrido[2,3-d]-pyrimidine-2,4(1H,3H)-dione ( 14a and 14b , respectively) were obtained in quantitative yields. A plausible mechanism for the formation of bicyclic compounds is discussed.     

A distance-controlled oligopeptide linker as a novel photo-induced energy transfer switch by secondary structural transition

By using an oligopeptide chain as a functional linker and introducing coumarin 2 and coumarin 343 at the chain ends, an effective photo-induced energy transfer system was constructed and energy transfer from coumarin 2 to coumarin 343 was switched on and off by a solvent-induced helix-coil secondary transition of the oligopeptide chain.     

Catalytic enantioselective Michael addition of 1,3-dicarbonyl compounds to nitroalkenes catalyzed by well-defined chiral ru amido complexes

Well-defined chiral Ru amido complexes promoted asymmetric Michael addition of 1,3-dicarbonyl compounds including malonates, beta-keto esters, and 1,3-diketones to nitroalkenes to give the corresponding adducts with excellent ees and in excellent yields.