Highly regioselective coupling reactions of allylic and propargylic alcohol derivatives with gamma,gamma-dialkoxyallylic zirconium species via Zr-to-Cu transmetalation

In the presence of CuCN, reaction of gamma,gamma-dialkoxyallylic zirconium species 4, generated in situ by treating triethyl orthoacrylate with zirconocene-butene complex, with allylic and propargylic phosphates proceeded at the alpha-position of 4 in a highly SN2'-selective manner to give the corresponding 5-alkenoates and 4,5-alkadienoates, respectively. In the present Cu(I)-mediated coupling reaction, the gamma,gamma-dialkoxyallylic zirconium species 4 serves as a synthetically useful homoenolate anion equivalent of propionate.     

Removal of lead ions in drinking water by coffee grounds as vegetable biomass

In an attempt to reuse food waste for useful purposes, we investigated the possibility of using coffee grounds to remove lead ions from drinking water. We studied the lead ion adsorption characteristics of coffee beans and grounds by measuring their fat and protein content, adsorption isotherms for lead ions, and adsorption rates for lead ions. The number of lead ions adsorbed by coffee grounds did not depend on the kind of coffee beans or the temperature at which adsorption tests were performed. The rate of lead ion adsorption by coffee grounds was directly proportional to the amount of coffee grounds added to the solution. When coffee grounds were degreased or boiled, the number of lead ions decreased. When proteins contained in coffee grounds were denatured, the lead ion adsorption was considerably reduced. The lead ion adsorption capacity of coffee grounds decreased with increased concentration of perchloric acid used for treating them and disappeared with 10% perchloric acid. The experiments demonstrated that proteins contained in coffee beans depend upon the adsorption of lead ion. The present study gave an affirmative answer to the possibility of using coffee grounds, an abundant food waste, for removing lead ions from drinking water.     

Adsorption of dyes onto carbonaceous materials produced from coffee grounds by microwave treatment

Organic wastes have been burned for reclamation. However, they have to be recycled and reused for industrial sustainable development. Carbonaceous materials were produced from coffee grounds by microwave treatment. There are many phenolic hydroxyl and carboxyl groups on the surface of carbonaceous materials. The base consumption of the carbonaceous materials was larger than that of the commercially activated carbon. The carbonaceous materials produced from coffee grounds were applied to the adsorbates for the removal of basic dyes (methylene blue and gentian violet) in wastewater. This result indicated that the adsorption of dyes depended upon the surface polar groups on the carbonaceous materials. Moreover, the Freundlich constants of isotherms for the adsorption of methylene blue and gentian violet onto the carbonaceous materials produced from coffee grounds were greater than those for adsorption onto activated carbon or ceramic activated carbon. The interaction was greatest between the surface or porosity of the carbonaceous materials and methylene blue and gentian violet. The microwave treatment would be useful for the carbonization of organic wastes to save energy.     

Phase equilibria in the water-dodecane-pentaoxyethylene dodecylether system

Summary Phase diagrams have been determined as a function of temperature for the following binary and ternary systems; water-pentaoxyethylene dodecylether system and water-dodecane systems containing 10, 20, 30, and 40 wt.-% of pentaoxyethylene dodecylether.X-ray diffraction examinations have revealed that the two lyotropic mesophases (neat phase and middle phase) are formed in the binary system. In the ternary systems, the mutual solubility of water and oil increases remarkably at a medium temperature near the phase inversion temperature in emulsion. The marked increase in mutual solubility is illustrated in the phase diagram as a narrow transparent region which has been regarded as a microemulsion. The electrical conductance, viscosity and type of flow behavior of the ternary system vary with temperature, corresponding to the structural changes of the system. The rheograms of the ternary systems have exhibited various types of flow behavior such asNewtonian flow, pseudoplastic flow, thixotropic hysteresis and dilatant hysteresis. Besides, differential scanning analysis has revealed endothermic peaks corresponding to phase transitions.

---

Zusammenfassung Zustandsdiagramme wurden als Funktion der Temperatur für folgende binäre und ternäre Systeme bestimmt: Wasser-Pentaoxydthylen-Dodecyläther und Wasser-Dodecan mit 10, 20, 30 und 40 Gew.-% von Pentaoxyäthylen-Dodecyläther.Die Röntgen-Diffraktion-Untersuchung ergab, daß zwei lyotropische mesomorphe Phasen (neat"-Phase und middle"-Phase) in dem binären System gebildet werden. In dem ternären System nimmt die gegenseitige Löslichkeit von Wasser und Öl bei einer mittleren Temperatur in der Nähe der Temperatur der Phasenumkehrung erheblich zu. Dieser Bereich erscheint im Zustandsdiagramm als ein schmales und transparentes Gebiet, welches als eine Mikroemulsion angesehen wird. Die elektrische Leitfähigkeit, die Viskosität und der Typ des Fließverhaltens des ternären Systems verändern sich je nach der Temperatur entsprechend einer Veränderung der Struktur des Systems. Rheogramme der ternären Systeme zeigen verschiedene Typen des Fließverhaltens, wie Newtonscher Fluß, pseudoplastischer Fluß, thixotropische Hysterese, dilatantische Hysterese. Die differentialkalorimetrische Analyse zeigte endotherme Effekte bei den entsprechenden Phasenumwandlungen.

     

Syntheses and electrochemical behaviour of novel dmit or dmio (dithiolato) cobalt(iii) complexes with a η5-cyclopentadienyl or η5-pentamethylcyclopentadienyl ring

Four novel cobalt(III) complexes with a cyclopentadienyl or pentamethylcyclopentadienyl ring and dmit or dmio ligands were synthesized, and their electrochemical behaviour was investigated. All these complexes exhibited three one-electron transfer steps: one reduction and two oxidation steps. In addition, a novel organosulphur compound was afforded by electrochemical oxidation of dmit cobalt complex. Thus, these complexes may have considerable synthetic potential as precursors for electron reservoirs and organosulphur compounds.     

Note on Hadamard tournaments of Szekeres type

An Hadamard 3-design involving an Hadamard tournament of Szekeres type involves and Hadamard tournament which is not equivalent with an Hadamard tournament of Szekeres type.     

Synthesis of the bicyclo[7.3.0]dodecatrienediyne core of the C-1027 chromophore

[reaction: see text] C-1027, an extremely potent antitumor agent, is composed of chromophore 1 and an apoprotein. Here we report a general and efficient route to the exceedingly reactive bicyclo[7.3.0]dodecatrienediyne core of 1, utilizing selenoxide elimination and epoxide deoxygenation to build the cyclopentadiene and enediyne structures, respectively.