TY - JOUR
T1 - Synthesis of bridged nicotinates having [n](2,5)pyridinophane skeletons (n=8-14)
AU - Kanomata, Nobuhiro
AU - Yamada, Shinsuke
AU - Ohhama, Takayuki
AU - Fusano, Akira
AU - Ochiai, Yoshiharu
AU - Oikawa, Jun
AU - Yamaguchi, Masahiro
AU - Sudo, Fumio
PY - 2006/4/24
Y1 - 2006/4/24
N2 - Synthesis of various bridged nicotinates 6 having [n](2,5)pyridinophane skeletons (n=8-14) was accomplished by the unique pyridine-formation reaction of methyl propiolate with a series of formyl-substituted (vinylimino)phosphoranes 5, which were prepared from the corresponding cycloalkanones 1 via Vilsmeier-Haack formylation giving chloro-substituted cycloalkenals 2, their thermal and photochemical transformation to formyl azirines 4, and the following ring-opening reactions with triphenylphosphine. The HPLC analysis of [11](2,5)pyridinophane derivatives, (Sp,S)-14 and (Rp,S)-14, showed that these diastereomers rapidly epimerize themselves at room temperature and that their planar-chirality was thermodynamically less stable as compared to the corresponding [11](2,5)cyclophane systems.
AB - Synthesis of various bridged nicotinates 6 having [n](2,5)pyridinophane skeletons (n=8-14) was accomplished by the unique pyridine-formation reaction of methyl propiolate with a series of formyl-substituted (vinylimino)phosphoranes 5, which were prepared from the corresponding cycloalkanones 1 via Vilsmeier-Haack formylation giving chloro-substituted cycloalkenals 2, their thermal and photochemical transformation to formyl azirines 4, and the following ring-opening reactions with triphenylphosphine. The HPLC analysis of [11](2,5)pyridinophane derivatives, (Sp,S)-14 and (Rp,S)-14, showed that these diastereomers rapidly epimerize themselves at room temperature and that their planar-chirality was thermodynamically less stable as compared to the corresponding [11](2,5)cyclophane systems.
KW - Aza-Wittig reactions
KW - Cycloaddition
KW - Planar-chirality
KW - Pyridine-formation reactions
KW - Pyridinophanes
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U2 - 10.1016/j.tet.2006.02.002
DO - 10.1016/j.tet.2006.02.002
M3 - Article
AN - SCOPUS:33645989427
VL - 62
SP - 4128
EP - 4138
JO - Tetrahedron
JF - Tetrahedron
SN - 0040-4020
IS - 17
ER -