Ethenetetracarbonitrile (2, in benzene solution) and 1,3-dioxoindan-2-ylidene propanedinitrile (4, in ethanol or acetonitrile solution) act on N-aryl-2,3-dihydro-1H-benz[d,e]isoquinolines 6a-d and N-aryl-6,7-dihydro-5H-dibenz[c,e]azepines 11a-d via hydride abstraction followed by addition of cyanide to the iminium carbon atom forming the corresponding 1- and 5-carbonitriles 9a-d and 13a-d, respectively, in moderate to medium yields.Additionally , the known 1,3-dihydroxy-2H-inden-2-ylidenepropanedinitrile 15 and a novel dispirocyclopropane (17) are formed from 4 in the reaction with 6 in acetonitrile and ethanol, respectively. The structures of 17 and 6-(4-methylphenyl)-6,7-dihydro-5H-dibenz[c,e]azepine-5-carbonitrile have been unambiguously confirmed by single-crystal X-ray crystallography.
© 1946 – 2014: Verlag der Zeitschrift für Naturforschung
