Anthracene copper catalysts

According to Sugino and Outi, the hydrogenation of anthracene to perhydroan-thracene over reduced copper catalyst proceeds through the intermediates shown in Scheme 11.18 the formation of these compounds depends on reaction temperatures.253... 

Scheme 11.18 Hydrogenation pathways of anthracene over reduced copper catalyst.

In 2014 several reports described the use of inverse-electron-demand Diels-Alder reactions to furnish naphthalene-based compounds from phthalazine-containing ring systems. Employing nonprecious metal complexes, copper(l) and nickel(O) complexes, instead of silver salts to catalyze formal [4+ 2] cycloadditions of 1,2-diazines and siloxyalkynes, Rawal and his group developed an environmentally friendlier and more economical method for preparing siloxy derivatives of naphthalene, anthracene, and phenanthrene (Scheme 16) (140L3236). In addition, the copper catalyst could also be employed for the synthesis of the corresponding quinolines and isoquinolines. This method provided the respective products in... 

Anthracene and phenanthrene can be converted to their 9,10-dihydroderivatives in high yield over copper chromite at 1(K)-150 °C and 150 atm. The change can be accomplished under milder conditions using platinum metal catalysts, Rh/AhOs with anthracene and Pd/C with phenanthrene. ... 

Electrolytic oxidation of anthracene in 20 per cent sulfuric acid solution with 1 per cent of vanadium pentoxide present is carried out at 80° C. with lead electrodes and a current density of 300 amperes per square meter at 1.6 volts. Good yields have been claimed 10 for this process. Air under pressure has been used for the oxidation of anthracene in the form of dispersions in aqueous ferric sulfate solutions,20 or as a solution iu pyridine or dispersion in aqueous alkaline solutions preferably in the presence of catalysts 21 of copper, cobalt, nickel or lead compounds. Vanadium compounds have been found more active than chromium compounds for use as oxidation catalysts in the form of suspensions in the liquid phase, as in the preparation of aniline black.22 Anthracene suspended in water or dilute sulfuric arid or dissolved in a solvent as acetone is oxidized with ozone, or ozonized oxygen at ordinary temperatures.28... 

Of particular interest are the solubilities of cobalt-, nickel- and copper-halide complexes in dense supercritical aqueous phases. Aquo- and halide complexes have higher coordination numbers at higher density. Several of gaseous solutions are highly coloured (for example dark blue cobalt-II solutions). Visible and UV-spectra, which permit to determine the stability ranges of various complexes have been reported by us up to 500 °C and 6000 bar [43-45]. The results may have interest for hiture catalyst developments. We have used near-UV spectroscopy to determine the solubility of organic solids in various dense gases. Examples are anthracene [46] and caffeine [47] to 200 °C and 2000 bar. Supercritical extraction has become a widely applied procedure in the food, pharmaceuticals and other industries. 

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