Département de chimie moléculaire

Cyclo[8]pyrrole was obtained efficiently when 3,3',4,4'-tetraethylbipyrrole was subjected to bulk electrolysis, with yields spanning a range from close to 0{%} with Bu4NF as the electrolyte, to almost 70{%} when Bu4N hydrogensulfate was used for this purpose. These observations are consistent with the conclusion that the reaction is controlled by anion-related factors such as a specific templating effect. Note that cyclo[8]pyrrole was the only detectable macrocyclic product obtained from 3,3',4,4'-tetraethylbipyrrole under the conditions of the electrochem. oxidn. When similar electrolyzes were performed by using 3,4-diethylpyrrole as the starting material, two products could be isolated, which were identified as being the cyclo[7]pyrrole and cyclo[8]pyrrole, resp. Detailed analyses of the oxidized forms of cyclo[7]pyrrole and cyclo[8]pyrrole revealed that under the conditions of the electrolysis these latter species are not stable. [on SciFinder(R)]