Scholl Reaction of an ortho-Phenylene-bridged Cyclic Pyrrole-Thiophene Hybrid Hexamer
Keyword(s):
X Ray
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Scholl reaction of ortho-phenylene-bridged cyclic pyrrole-thiophene hybrid hexamer exclusively gave a cyclophane-type compound of [5]heterohelicenes in 45% yield. The structure was unambiguously revealed by X-ray diffraction analysis. This helicenophane-type compound showed sharp absorption and fluorescence spectra, reflecting its rigid structure. The reaction path was analyzed on the basis of DFT calculations. The reaction path was analyzed on the basis of DFT calculations, and it was found that the formation of 8 is thermodynamically favored and further oxidation is prohibited due to the increased strain energy.