Chinone. XIII. Synthese von 4,5,9,10-Tetrahydropyren-2,7-dion und Versuch zur Darstellung von Pyren-2,7-dion

Abstract

Quinones. XIII. Synthesis of 4,5,9,10‐Tetrahydropyrene‐2,7‐dione and Attempted Preparation of Pyrene‐2,7‐dione The titel quinones 7 and 9 are of interest as electron acceptors for organic conductors. The synthesis of their conjugate hydroquinones 6 and 8 via the metacyclophane derivative 3 is described. The tetrahydropyrene‐2,7‐dione 7 – obtained by oxidation of 6 – possesses only a limited stability, whereas pyrene‐2,7‐dion (9) proved to unstable to be isolated.

Synthesis of 2‐ and 2,7‐Functionalized Pyrene Derivatives: An Application of Selective CH Borylation

“…Aryl triflates have also been used as electrophiles in many coupling reactions, and the conversion of boronate esters to alcohols and then triflates is known 39. The oxidation of 1 at room temperature with H 2 O 2 /NaOH for 4 h in THF/H 2 O gave 2,7‐dihydroxypyrene ( 5 )40 in 89 % yield (Scheme d); analogously, 2 was converted to 2‐hydroxypyrene ( 21 ) in 84 % yield (Scheme a). Compound 21 has been previously prepared in moderate yield from 20 by the formation of its Grignard reagent and subsequent reaction with diborane and alkaline H 2 O 2 16c.…”

“…2,7‐Dihydroxypyrene (5) :40 Compound 1 (0.50 g, 1.1 mmol) and NaOH (0.26 g, 6.5 mmol) were dissolved in THF (50 mL) and an aqueous solution of H 2 O 2 (0.66 g, 6.5 mmol, 35 wt %) was added to this mixture. After stirring at room temperature for 4 h, the solution was acidified to pH 1–2 by using 1 M HCl.…”

“…The mixture was added to a Youngs tube containing pyrene (0.71 g, 3.5 mmol) and B 2 pin 2 (1.95 g, 7.68 mmol). After addition of THF (10 mL), the tube was sealed and the reaction mixture was stirred at 80 8C for 16 h. The mixture was transferred to a round-bottomed flask and THF/MeOH (1:1, 60 mL) was added, followed by CuBr 2 ( 2,7-Dihydroxypyrene (5): [40] Compound 1 (0.50 g, 1.1 mmol) and NaOH (0.26 g, 6.5 mmol) were dissolved in THF (50 mL) and an aqueous solution of H 2 O 2 (0.66 g, 6.5 mmol, 35 wt %) was added to this mixture. After stirring at room temperature for 4 h, the solution was acidified to pH 1-2 by using 1 m HCl.…”

Electrosynthesis of Pyrenediones on Carbon Nanotube Electrodes for Efficient Electron Transfer with FAD‐dependent Glucose Dehydrogenase in Biofuel Cell Anodes

“…These deposits were subsequently immersed in 0.75 mL CDCl 3 to desorb the formed pyrenedioness from the MWCNTs. It should be noted that no characteristic peak of 4,5-pyrenedione or 4,5,9,10-pyrenetetrone, or any other pyrene quinones, [16] could be resolved. Figure 2 shows the measured features between 6.6 and 8.8 ppm.…”

“…By integration of the peaks H and D, a ratio of the electrosynthesized 1,6pyrenedione and 1,8-pyrenedione of 2 : 1 can be determined. It should be noted that no characteristic peak of 4,5-pyrenedione or 4,5,9,10-pyrenetetrone, or any other pyrene quinones, [16] could be resolved. [13a] The detailed assignments of the peaks: 1,6-pyrenedione 1 Based on these ratios and the pH effect, a mechanism for the electro-oxidation of pyrene in buffer solution can be proposed according to the mechanism of the oxidative photolysis of pyrene in water.…”