Synthesis, Chemistry and Structure of Some 1, 1‐Dimethylcyclopropazulenes. Issue 16 (11th October 2016) - Payne, Alan D.
Abstract: 1, 1‐Dimethylcycloprop[ e ]azulene and 1, 1‐dimethylcycloprop[ f ]azulene derivatives were prepared through a short synthesis from thiophene‐1, 1‐dioxides using a Houk‐Leaver azulene synthesis. The strain caused by the fusion of the cyclopropane ring had no effect on electrophilic aromatic substitution reactions. X‐ray structures of these compounds showed that cycloprop[ e ]azulenes have no or very small strain induced bond localisation, whereas cycloprop[ f ]azulene shows some minor localisation. Abstract : 1, 1‐Dimethylcycloprop[ e ]azulenes and 1, 1‐dimethylcycloprop[ f ]azulene were prepared through a short synthesis from thiophene‐1, 1‐dioxides using a Houk‐Leaver azulene synthesis. The strain caused by the fusion of the cyclopropane ring had no effect on electrophilic aromatic substitution reactions. X‐ray structures of these compounds showed that cycloprop[ e ]azulenes have no or very small strain induced bond localisation, whereas cycloprop[ f ]azulene shows some minor localisation.