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
N1 - Funding Information:
This work was financially supported by JSPS Grant-in-Aid for Scientific Research (B) (14350479) and by the Asahi Glass Foundation, Japan. We thank Mr. Katsuhito Tomono, Mr. Hironobu Kubota, and Mr. Narihito Ogawa (Meiji University) for their technical assistance in obtaining some experimental data.
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 -