TY - JOUR
T1 - Retro-Diels-Alder approach to the synthesis of π-expanded azuliporphyrins and their porphyrinoid aromaticity
AU - Okujima, Tetsuo
AU - Kikkawa, Tasuku
AU - Nakano, Haruyuki
AU - Kubota, Hiroshi
AU - Fukugami, Nobumasa
AU - Ono, Noboru
AU - Yamada, Hiroko
AU - Uno, Hidemitsu
PY - 2012/10/1
Y1 - 2012/10/1
N2 - Bicyclo[2.2.2]octadiene (BCOD) fused azuliporphyrins were synthesized by 3+1 porphyrin synthesis of azulitripyrranes with diformylpyrroles. Subsequent retro-Diels-Alder reaction of the BCOD-fused azuliporphyrins afforded azulibenzo-, azulidibenzo-, and azulitribenzoporphyrins 1-5. NMR and UV/Vis spectra, as well as nucleus-independent chemical shift (NICS) calculations revealed that 1-5 and their diprotonated dications exhibit relatively low porphyrinoid aromaticity, which was dependent on the position and number of fused benzene rings present. Porphyrins: A series of azulibenzoporphyrins were synthesized based on 3+1 porphyrin synthesis and retro-Diels-Alder reaction of bicyclo[2.2.2]octadiene-fused precursors (see scheme). UV/Vis spectra and NICS calculations revealed that their diprotonated dications exhibited a low porphyrinoid aromaticity from the porphyrinlike π circuit, which was dependent on the position and number of fused benzene rings.
AB - Bicyclo[2.2.2]octadiene (BCOD) fused azuliporphyrins were synthesized by 3+1 porphyrin synthesis of azulitripyrranes with diformylpyrroles. Subsequent retro-Diels-Alder reaction of the BCOD-fused azuliporphyrins afforded azulibenzo-, azulidibenzo-, and azulitribenzoporphyrins 1-5. NMR and UV/Vis spectra, as well as nucleus-independent chemical shift (NICS) calculations revealed that 1-5 and their diprotonated dications exhibit relatively low porphyrinoid aromaticity, which was dependent on the position and number of fused benzene rings present. Porphyrins: A series of azulibenzoporphyrins were synthesized based on 3+1 porphyrin synthesis and retro-Diels-Alder reaction of bicyclo[2.2.2]octadiene-fused precursors (see scheme). UV/Vis spectra and NICS calculations revealed that their diprotonated dications exhibited a low porphyrinoid aromaticity from the porphyrinlike π circuit, which was dependent on the position and number of fused benzene rings.
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U2 - 10.1002/chem.201201399
DO - 10.1002/chem.201201399
M3 - Article
C2 - 22915443
AN - SCOPUS:84867043681
SN - 0947-6539
VL - 18
SP - 12854
EP - 12863
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
IS - 40
ER -