1999 Fiscal Year Final Research Report Summary
Exploitation of Practical Method for Asymmetric Functionalization of Alkenes
| Project/Area Number |
09554048
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 展開研究 |
|---|
| Research Field |
物質変換
|
|---|
| Research Institution | KYUSHU UNIVERSITY |
|---|
Principal Investigator |
KATSUKI Tsutomu Kyushu Univ., Fac. Sci., Professor, 大学院・理学研究科, 教授 (40037271)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
SUZUKI Kenji Nissan Chem. Ind. Ltd., Res. Chairman, 中央研究所, 主任研究員
IRIE Ryo Kyushu Univ., Fac. Sci., Research Associate, 大学院・理学研究科, 助手 (70243889)
ITO Yoshio Kyushu Univ., Fac. Sci., Associate Professor, 大学院・理学研究科, 助教授 (00221086)
|
|---|
| Project Period (FY) |
1997 – 1999
|
| Keywords | (salen)manganese / asymmetric epoxidation / cyclopropanation / desymmetrization / (salen)ruthenium / pyridine N-oxide / (salen)cobalt(II) / tris(oxazoline)copper |
|---|
| Research Abstract |
We have studied asymmetric epoxidation using optically active (salen)manganese complexes and applied for the synthesis of several optically active important compounds. In this research project, we aimed at extension of the scope of substrates used in the epoxidation and exploitation of new chiral complexes to enable several important asymmetric reactions such as asymmetric oxidation of C-H bond, cis-selective asymmetric cyclopropanation. During three years, we could receive following impressive results.
1. Enantioselective hydroxylation of C-H bond of meso-tetrahydrofurans was found to proceed with high selectivity (up to 90% ee) by using optically active (salen)manganese complex as a catalyst. This asymmetric reaction was successfully applied to the synthesis of (-)- Alloyohimbane and (-)-Swainsonine.
2. Newly prepared (salen)ruthenium complex bearing nitrosyl group at the apical position was found to show unique asymmetric catalysis. Under the irradiation, the complex showed catalytic activity for epoxidation by using 2, 6-dichloropyridine N-oxide as a terminal oxidant. High enantioselectivity was observed not only for the epoxidation of cis-disubstituted olefins but also that of trans- and terminal olefins differing from the previously reported epoxidation catalyzed by (salan)manganese complex. Furthermore, the reaction was highly stereospecific and produced epoxides without isomerization of the geometry of double bond.
3. Highly cis- and enantio-selective cyclopropanation was realized by using (salen)cobalt(II) complex. By this achievement, all the possible stereochemistry in cyclopropanation could be for the first time controlled chemically.
4. High enantioselectivity more than 80% ee could be observed in the asymmetric C-H Oxidation at a allylic position of racemic olefins by using optically active tris(oxazoline)copper complex.
|
