Strategic Synthesis of ‘Picket Fence’ Porphyrins Based on Nonplanar Macrocycles
Citation:
Norvaiša K, Yeow K, Twamley B, Roucan M, Senge MO. Strategic Synthesis of 'Picket Fence' Porphyrins Based on Nonplanar Macrocycles, European Journal of Organic Chemistry, 2021 Mar 26;2021(12):1871-1882Abstract:
Traditional ‘picket fence’ porphyrin systems have been a topic of interest for their capacity to direct steric shielding effects selectively to one side of the macrocycle. Sterically overcrowded porphyrin systems that adopt macrocycle deformations have recently drawn attention for their applications in organocatalysis and sensing. Here we explore the combined benefits of nonplanar porphyrins and the old molecular design to bring new concepts to the playing field. The challenging ortho-positions of meso-phenyl residues in dodecasubstituted porphyrin systems led us to transition to less hindered para- and meta-sites and develop selective demethylation based on the steric interplay. Isolation of the symmetrical target compound [2,3,7,8,12,13,17,18-octaethyl-5,10,15,20-tetrakis(3,5-dipivaloyloxyphenyl)porphyrin] was investigated under two synthetic pathways. The obtained insight was used to isolate unsymmetrical [2,3,7,8,12,13,17,18-octaethyl-5,10,15,20-tetrakis(2-nitro-5-pivaloyloxyphenyl)porphyrin]. Upon separation of the atropisomers, a detailed single-crystal X-ray crystallographic analysis highlighted intrinsic intermolecular interactions. The nonplanarity of these systems in combination with ‘picket fence’ motifs provides an important feature in the design of supramolecular ensembles.
Sponsor
Grant Number
Science Foundation Ireland
IvP13/IA/1894)
Author's Homepage:
http://people.tcd.ie/sengem
Author: Senge, Mathias
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Journal ArticleCollections
Series/Report no:
European Journal of Organic Chemistry;2021;
12;
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Full text availableDOI:
http://dx.doi.org/10.1002/ejoc.202100154Metadata
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