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B III 5‐Arylsubporphyrins and B III Subporphine
Author(s) -
Kise Koki,
Yoshida Kota,
Kotani Ryota,
Shimizu Daiki,
Osuka Atsuhiro
Publication year - 2018
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201801491
Subject(s) - triethylamine , borane , chemistry , triethyl orthoformate , yield (engineering) , medicinal chemistry , nitro , aryl , salt (chemistry) , boron , molecule , chloride , condensation , polymer chemistry , catalysis , organic chemistry , materials science , alkyl , physics , metallurgy , thermodynamics
Boron(III) 5‐arylsubporphyrins and B III subporphine are promising precursors for functional B III subporphyrins bearing asymmetric meso ‐substituents. Herein, we report the first synthesis of these molecules. Among many aryl acid chlorides examined, 4‐nitrobenzoyl chloride gave B III 5‐(4‐nitrophenyl)subporphyrin in 10 % yield in condensation with triethylamine‐tri‐ N ‐tripyrromethene‐borane. The nitro group of this B III subporphyrin was reduced with NaBH 4 to prepare B III 5‐(aminophenyl)subporphyrin, which was converted into B III 5‐phenylsubporphyrin via the corresponding diazonium salt. B III subporphine was synthesized by condensation of triethyl orthoformate with triethylamine‐tri‐ N ‐tripyrromethene‐borane. Progressive removal of meso ‐phenyl substituents leads to continuous changes in the optical properties, whereas the B III subporphine deviates from this trend in some properties.