Dissolving metal reduction of aceanthrylene and NMR analysis of a rigid, boat-shaped 9,10-dihydroanthracene

Abstract

Aceanthrylene is reduced by sodium/ammonia solution to its 2,6-dihydro derivative (4), which indicates a protonation site in the dianion in contrast to the MNDO-calculated position of highest electron density. It is concluded that monoanion stability must be the prevailing feature. Compound 4 is also reduced by sodium/ammonia to provide 1,9-ethano-9,10-dihydroanthracene, which allowed the first proton NMR study of a rigid, boat-shaped dihydroanthracene. Especially interesting are the long range, five-bond homoallylic couplings between the 9and 10-positions, and the values measured are 4.7 Hz for 123456=/9i10 (dipseudoaxial) and 1.4 Hz for sJ9|1(y (pseudoaxial/pseudoequatorial). The protonation and alkylation of (3-phenylindenyl)lithium is also considered so as to better understand the behavior of the intermediates derived from aceanthrylene.

One Step Pd(0)-Catalyzed Synthesis, X-ray Analysis, and Photophysical Properties of Cyclopent[hi]aceanthrylene: Fullerene-like Properties in a Nonalternant Cyclopentafused Aromatic Hydrocarbon

“…The low LUMO levels predict a very facile two-electron reduction in the case of 2c. Although the two-electron chemical reduction of the parent aceanthrylene has been analyzed in some detail, 25 attempts to measure the electrochemical reduction of the alkynyl-containing aceanthrylene 2b were unsuccessful as it decomposed readily under the conditions of cyclic voltammetry measurements. In contrast, the cyclic voltammogram of 2c obtained with a scanning rate of 50 mV/s at ambient temperature with Bu 4 NPF 6 in MeCN reveals the predicted behavior (Figure 10).…”

Reactivity of the 5-Hydroacenaphthylene Anion towards Electrophiles

“…[2] [9] using 2.2 equivalents of sodium in anhydrous THF and selective: alkylation occurred at position 1 as well as at position 2a. [2] [9] using 2.2 equivalents of sodium in anhydrous THF and selective: alkylation occurred at position 1 as well as at position 2a.…”

Single Electron Transfer vs. SN2 Reaction

“…Reduction schemes for polycyclic aromatic hydrocarbons, a: Birch-type, b: aprotic the reactivity of the PAH (Scheme 1a, ). [1] [2] [3] In a more convenient and more selective procedure than this Birchlike reduction, pure THF is used as solvent and the sodium is activated by ultrasonic vibration (Scheme 1, b). By means of this alternate procedure, acenaphthylene (1) can be converted easily and quantitatively into its dianion 1 2-(Scheme 2).…”