| Co-Investigator(Kenkyū-buntansha) |
MENAHAM Kaft テクニオン大学, 化学部, 教授
ISRAEL Goldb テルアビブ大学, 化学部, 教授
MAIR Lahav ワイズマン研究所, 化学部, 教授
MIYAMOTO Hisakazu Assistant, Faculty of Engineering, Ehime University, 工学部, 助手 (30229893)
TANAKA Koichi Lecturer, Faculty of Engineering, Ehime University, 工学部, 講師 (10116949)
LAHAV Mair Professor, Weizman Institute, Israel
GOLDBERG Lsrael Professor, Department of Chemistry, Tel Aviv University, Israel
KAFTORY Menaham Professor, Department of Chemistry, Technion University, Israel
|
|---|
| Research Abstract |
Precise molecular recognition in the solid state are interesting in relating to that in living body. Studies of the solid state molecular recognition are also important in relating to development of new preparative method of optically active materials by optical resolution and enantioselective reactions. Some optical resolution and enantioselective reactions have been developed by using host-guest complex crystals. In the host-guest complex, the both components recognize the size, shape, and chirality of molecules each other. The mechanism of the molecular recognition has been studied by X-ray crystal structural study of the host-guest inclusion complex. By refering to the analyzed result, some new host-guest complexes were designed.
1. By complexing with optically active 2, 2'-dihydroxy-1, 1'-binaphthyl (1), some selenoxides and arsine oxides were resolved efficiently. Optically active 9, 9'-dihydroxy-10, 10'-biphenanthryl (2) was found to be effective for optical resolution of some be
… More
ta-lactam derivatives. X-Ray crystal structural study of these inclusion complexes disclosed that hydrogen bond formation between the hydroxyl group of 1 or 2 and the guest compound is important. Host compounds (3) which were derived from tartaric acid are useful for optical resolution of aziridine derivatives. Although resolution of oxime has never been succeeded so far, some cyclohexanone oximes were efficiently resolved by complexation with optically active 1, 6-di (o-chlorophenyl) -1, 6-diphenylhexa-2, 4-diyne- 1, 6-diol (4). The most interesting resolution has been achieved in the solid state. Mixing the optically active host 3 and rasemic beta-ionone epoxide (5) in the solid state gave a complex of 3 and optically active 5 of 88% ee. This shows that an enantioselective complexation occurs in the solid state. By using this phenomenon, an interesting kinetic resolution of 5 has also been achieved.
2. We found that many organic reactions occur efficiently and selectively in the solid state. In some cases, the efficiency and selectivity are much higher in the solid state than in solution. Treatment of inclusion complex of 4-methyl or 3, 5-dimethylcyclohexanone and 3 with Wittig-Horner reagent, for example, ph_3P=CHCOOEt in the solid state gave optically active olefin of 58-73% ee. Irradiation of a 1 : 2 inclusion complex of 4 and cycloocta02, 4, 6-trien-l-one (6) in the solid state gave optically active photodimer of 6, however, the similar irradiation of a 1 : 1 complex of 3 and 6 gave optically active intramolecular photocyclization product. X-Ray crystal structural study, clarified the mechanism of the photoreactions. It is useful to be able to control the type and steric course of photoreaction of 6 by changing the host compound. Aldol condensation reactions were also found to proceed in the solid state much faster than in solution. When the aldol reaction is carried out in an inclusion complex with optically active host, enantioselective reaction occurred to give optically active aldol. Less
|
