Alina Schreivogel, J. Maurer, R. Winter
Aug 1, 2006
Citations
0
Influential Citations
42
Citations
Journal
European Journal of Organic Chemistry
Abstract
Tetrakis(4-acetoxy- and 4-benzoyloxyphenyl)ethenes 1f,g were obtained by acylation of tetrakis(4-hydroxyphenyl)ethene 1b. Ullmann etherification of 4,4’-dihydroxybenzophenone 2b and subsequent McMurry coupling yielded tetrakis(phenoxyphenyl)ethene 1i. The tetrakis( acetamidophenyl)ethene 1h was prepared in three steps from tetraphenylethene 1c via nitration, Raney-Ni reduction and acetylation. Alternatively, trifluoroacetamide 1j, 2-methylhexanamide 1k, and 2,4-dimethylbenzamide 1l with less tendency to form 2D hydrogen bonding networks and thus increased solubility as compared to 1h were prepared by acylation of 4,4’-diaminobenzophenone 2a and subsequent McMurry coupling. Compounds 1f–l were investigated by cyclic voltammetry. While phenylether derivative 1i displays single electron processes during oxidation, a two-electron process was discovered for trifluoroacetamide 1j as was also supposed for the esters 1f,g. In addition, comproportionation constants were shown to be dependent on the solvent. In situ IR spectroelectrochemistry provided evidence for quinoidal type substructures in the dioxidized forms of tetraphenylethenes 1.