Atropisomers of meso Tetra(N-Mesyl Pyrrol-2-yl) Porphyrins: Synthesis,Isolation and Characterization of All-Pyrrolic Porphyrins |
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| Authors: | Leiming Zhu Leonard Himmel Jean Michél Merkes Prof. Dr. Fabian Kiessling Prof. Dr. Magnus Rueping Dr. Srinivas Banala |
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| Affiliation: | 1. Institute for Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany;2. Institute for Experimental Molecular Imaging, Uniclinic, RWTH Aachen University, Forckenbeckstr 55, 52074 Aachen, Germany;3. Institute for Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900 Saudi Arabia |
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| Abstract: | Atropisomerism has been observed in a variety of biaryl compounds and meso-aryl substituted porphyrins. However, in porphyrins, this phenomenon had been shown only with o-substituted 6-membered aromatic groups at the meso-position. We show herein that a 5-membered heteroaromatic (N-mesyl-pyrrol-2-yl) group at the meso-position leads to atropisomerism. In addition, we report a ‘one-pot’ synthetic route for the synthesis of ‘all-pyrrolic’ porphyrin (APP) with several N-protection groups (Boc, Cbz, Ms and Ts). Among these groups, we found that only the Ms group gave four individually separable atropisomers of meso-tetra(N-Ms-pyrrol-2-yl) porphyrin. Furthermore, the reductive removal of Cbz- was achieved to obtain meso-tetra(pyrrol-2-yl) porphyrin. Thus, our synthetic procedure provides an easy access to a group of APPs and stable atropisomers, which is expected to expand the application of novel APP-based materials. |
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| Keywords: | atropisomers meso tetra(pyrrol-2-yl) porphyrin porphyrinoids absorption spectra porphyrins transition-metal complexes |
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