Verschiedene Methoden

Ohne Zusammenfassung     

'Upenamide: An unprecedented macrocyclic alkaloid from the Indonesian sponge Echinochalina sp

'Upenamide (1) represents a new class of macrocyclic marine alkaloid possessing both spirooxaquinolizidinone and hemiaminal ring systems. It was isolated from the Indonesian sponge Echinochalina sp. The gross structure of 1 was elucidated by spectroscopic methods and accurate mass measurements. A suggestion is made as to its biogenetic origin.     

Indolyne experimental and computational studies: synthetic applications and origins of selectivities of nucleophilic additions

Efficient syntheses of 4,5-, 5,6-, and 6,7-indolyne precursors beginning from commercially available hydroxyindole derivatives are reported. The synthetic routes are versatile and allow access to indolyne precursors that remain unsubstituted on the pyrrole ring. Indolynes can be generated under mild fluoride-mediated conditions, trapped by a variety of nucleophilic reagents, and used to access a number of novel substituted indoles. Nucleophilic addition reactions to indolynes proceed with varying degrees of regioselectivity; distortion energies control regioselectivity and provide a simple model to predict the regioselectivity in the nucleophilic additions to indolynes and other unsymmetrical arynes. This model has led to the design of a substituted 4,5-indolyne that exhibits enhanced nucleophilic regioselectivity.     

A new twist in anion binding: metallo-helicate hosts for anionic guests

The condensation of 5-chlorocarbonyl-2,2'-bipyridine with a variety of rigid aromatic diamines, L, gave a series of new bisamido-2,2'-bipyridine based ligands (L = 4,4'-methylenediamine, L1; L = 1,1-bis(4-aminophenyl)cyclohexane, L2; L = 1,1-bis(4-amino-3,5-dimethylphenyl)cyclohexane, L3) capable of forming dinuclear triple helicate complexes on coordination to Fe(II). The reaction of various Fe(II) salts with gave: {[Fe2(L1)3](BF4)4, 1; [Fe2(L1)3](ClO4)4, 2; [Fe2(L1)3]Cl4, 3; [Fe2(L1)3](SO4)2, 4; [Fe2(L2)3](BF4)4, 5; [Fe2(L2)3]Cl4, 6; [Fe2(L3)3](BF4)4; 7; [Fe2(L3)3]Cl4, 8; and [Fe2(L3)3](SO4)2, 9, as determined by UV-Vis, IR and 1H NMR spectroscopy, electrospray mass spectrometry (ESMS) and elemental analyses. A UV-Vis complexometric titration experiment between L3 and Fe(BF4)2 established conclusively a [Fe2(L3)3]4+ product species. 1H NMR spectroscopy showed that the complexes exist as both rac-(helical) and meso-(non-helical) isomers in DMSO-d6 solution at 298 K. L1-L3 were designed such that following complexation, six amide hydrogen atoms would line an inter-strand intrahelical cavity of sufficient size to facilitate the binding of guest species within it. Indeed, ESMS studies showed characteristic peaks typical of complex-anion species in solution. Furthermore, 1H NMR titration experiments showed that anions bind within the intrahelical cavity as titration of 1, 5 and 7 with Bu4NCl showed significant downfield shifts in the amide and bipyridyl H6 proton resonances to yield a species of 1 : 2 host to guest stoichiometry. Moreover, addition of Bu4NCl to 1, 5 and 7 shifted the rac-/meso-species distribution from 1 : 2 in favour of the meso- to 100% in favour of the rac-isomer, showing that Cl- ions favour the formation of the triple helicate species in DMSO-d6 solution.     

Fused indoles. 1. Synthesis of the 1,9-dihydrothiazino[3,4-b] indole ring system

The title compounds were prepared by treating 2-chloroindole-3-carboxaldehydes and 3-acetyl-2-chloroindole with N-methylmethanesulfonamide and cyclizing the resulting intermediates with sodium hydride. Spectral data of the products are also discussed. J. Chem. Soc., 14, 1117 (1977)     

The chemistry of 2H-3,1-benzoxazine-2,4(1H)dione (isatoic anhydride). 7. Reactions with anions of active methylenes to form quinolines

The reaction of isatoic anhydrides with carbanions of various active methylene compounds is described. The isolation of 2-oxo or 4-oxoquinolines is possible by varying the functional groups flanking the methylene carbon.     

用于大肠杆菌消毒的负载型和悬浮型TiO_2催化剂的动力学和催化效率（英文）

TiO2‐mediated photocatalysis is widely used in a variety of applications and products in the envi‐ronmental and energy fields, including photoelectrochemical conversion, self‐cleaning surfaces, and especially water purification systems. The dimensionality of the structure of a TiO2 material can affect its properties, functions, and more specifically, its photocatalytic performance. In this work, the photocatalytic inactivation of Gram‐negative Escherichia coli using three photocatalysts, differ‐ing in their structure and other characteristics, was studied in a batch reactor under UVA light. The aim was to establish the disinfection efficiency of solid TiO2 compared with that of suspended cata‐lysts, widely considered as reference cases for photocatalytic water disinfection. The bacterial inac‐tivation profiles obtained showed that: (1) the photoinactivation was exclusively related to the quantity of photons retained per unit of treated volume, irrespective of the characteristics of the photocatalyst and the emitted light flux densities;(2) across the whole UV light range studied, each of the photocatalytic solids was able to achieve more than 2 log bacterial inactivation with less than 2 h UV irradiation;(3) none of the used catalysts achieved a total bacterial disinfection during the treatment time. For each of the catalysts the quantum yield has been assessed in terms of disinfec‐tion efficiency, the 2D material showed almost the same performance as those of suspended cata‐lysts. This catalyst is promising for supported photocatalysis applications.