1229863-57-3Relevant articles and documents
Synthesis and studies of thiacorroles
Shetti, Vijayendra S.,Prabhu, Uday R.,Ravikanth, Mangalampalli
, p. 4172 - 4182 (2010)
The first examples of stable 22-thiacorroles containing a direct pyrrole-pyrrole bond were synthesized using thiophene monocarbinols as key precursors. Condensation of 1 equiv of thiophene monocarbinol with 1 equiv of substituted aldehyde and 1.5 equiv of pyrrole under refluxing propionic acid conditions followed by alumina column chromatographic purification yielded the desired 22-thiacorroles. Although the corrole formation had been observed with variety of substituted aldehydes, the stable thiacorroles were isolated in 2-3% yields only with 4- and 3-nitrobenzaldehydes. The stable thiacorroles were obtained only under harsh propionic acid conditions and any other mild reaction conditions did not yield 22-thiacorroles. The structure of thiacorroles were unambiguously established using mass, and 1D and 2D NMR spectroscopy. The NMR study indicated diminished ring current and distortion of 22-thiacorroles. DFT studies also supported the distortion of thiacorroles. The absorption spectra showed reduction in number of absorption bands and fluorescence study indicated that 22-thiacorroles are weakly fluorescent. The electrochemical studies indicated that 22-thiacorroles undergo easier reductions compared to thiaporphyrins.
