Reactions with copper pads

For the recyclability of catalyst 1, after completion of the oxidation of 4-methoxybenzyl alcohol, the reaction mixmre was treated with water (3 mL), and the organic layer, after drying (Na2S04) and GC analysis, was passed through a short pad of silica gel using ethyl acetate and hexane as eluent to afford analytically pure 4-methoxybenzaldehyde in quantitative yield. Evaporation of the aqueous layer afforded the copper complex 1 that was subsequently reused for the oxidation of 4-methoxybenzyl alcohol up to three times using fresh TEMPO whereupon no loss of activity was observed. 

Diphenyl-4//-teUurin-4-ylidene)-2,6-copper powder are added to toluene (5 ml/mmol thione) and the mixture is heated under reflux for 1.5 h. The hot reaction mixture is filtered through a 5 cm pad of Celite, the pad is washed with dichloromethane, and the combined filtrate and washings are concentrated. The resultant precipitate is collected and the product (which is much less soluble in hot acetonitrile than the thione) is purified by fractional recrystallization from acetonitrile yield 66% m.p. 274°. 

Potassium 2-nitrobenzoate (22.6 g, 110 mmol), (l,10-phenanthroline)bis(triphenyl-phosphine)copper(I) nitrate (1.25 g, 1.50 mmol), and palladium acetylacetonate were diluted in deoxygenated, anhydrous mesitylene (150 mL), and 2-bromotoluene (12.3 mL, 100 mmol) was added under an atmosphere of nitrogen. The reaction mixture was stirred for 16 h at 150 °C internal temperature. After cooling to ambient temperature, the reaction mixture was filtered through a pad of Celite and the filter cake was rinsed with ethyl... 

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