TY - JOUR
T1 - 1,1-Ethylene-1H-azulenium ion and its alkyl substituted derivatives
T2 - Synthesis, characterization, and some reactions thereof
AU - Oda, Mitsunori
AU - Kajioka, Takanori
AU - Uchiyama, Takuya
AU - Nagara, Kohki
AU - Okujima, Tetsuo
AU - Ito, Shunji
AU - Morita, Noboru
AU - Sato, Toshio
AU - Miyatake, Ryuta
AU - Kuroda, Shigeyasu
N1 - Funding Information:
This work was supported by a Grant-in-Aid Scientific Research (No. 09640631) from the Ministry of Education,
PY - 1999/5/7
Y1 - 1999/5/7
N2 - 1,1-Ethylene-1H-azulenium tetrafluoroborate (1b) and its alkyl substituted derivatives, 6-t-butyl (1c) and 4-isopropyl-3,8-dimethyl ones (Id), were synthesized starting from their corresponding azulenes by a three- step sequence which includes reduction, cyclopropanation and hydride abstraction reactions. The cation 1b and its 6-t-butyl derivative 1c, generated in deuterated acetonitrile at -20 °C, were characterized by low- temperature NMR spectroscopy. On the other hand, the cation Id was isolated os slightly unstable, greenish-yellow crystals. While the cation 1b in solution underwent expansion of the cyclopropane ring at elevated temperatures, 1c and 1d just decomposed. All the cations were found to react easily with nucleophiles to give thermodynamically controlled, stable addition products at their cyclopropane methylene carbons.
AB - 1,1-Ethylene-1H-azulenium tetrafluoroborate (1b) and its alkyl substituted derivatives, 6-t-butyl (1c) and 4-isopropyl-3,8-dimethyl ones (Id), were synthesized starting from their corresponding azulenes by a three- step sequence which includes reduction, cyclopropanation and hydride abstraction reactions. The cation 1b and its 6-t-butyl derivative 1c, generated in deuterated acetonitrile at -20 °C, were characterized by low- temperature NMR spectroscopy. On the other hand, the cation Id was isolated os slightly unstable, greenish-yellow crystals. While the cation 1b in solution underwent expansion of the cyclopropane ring at elevated temperatures, 1c and 1d just decomposed. All the cations were found to react easily with nucleophiles to give thermodynamically controlled, stable addition products at their cyclopropane methylene carbons.
KW - Azulenium ions
KW - Carbocations
KW - Spiro compounds
KW - Tropylium ions
UR - http://www.scopus.com/inward/record.url?scp=0033532013&partnerID=8YFLogxK
U2 - 10.1016/S0040-4020(99)00280-X
DO - 10.1016/S0040-4020(99)00280-X
M3 - 学術論文
AN - SCOPUS:0033532013
SN - 0040-4020
VL - 55
SP - 6081
EP - 6096
JO - Tetrahedron
JF - Tetrahedron
IS - 19
ER -