Exploitation of Practical Method for Asymmetric Functionalization of Alkenes

烯烃不对称官能化实用方法的开发

基本信息

批准号：
09554048
负责人：
KATSUKI Tsutomu
金额：
$ 7.74万
依托单位：
KYUSHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

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.

我们研究了使用光学活性（salen）锰配合物的不对称环氧化反应，并应用于几种光学活性重要化合物的合成。在这个研究项目中，我们的目标是扩大环氧化反应的底物范围并开发新的手性配合物，以实现一些重要的不对称反应，例如C-H键的不对称氧化、顺式选择性不对称环丙烷化。三年来，我们取得了以下令人瞩目的成果： 1．通过使用光学活性（salen）锰络合物作为催化剂，发现内消旋四氢呋喃的 C-H 键的对映选择性羟基化反应具有高选择性（高达 90% ee）。该不对称反应成功应用于(-)-Alloyohimbane和(-)-Swainsonine的合成。2．发现新制备的在顶端位置带有亚硝酰基的(salen)钌络合物表现出独特的不对称催化作用。在辐照下，配合物以2, 6-二氯吡啶N-氧化物为末端氧化剂表现出环氧化催化活性。与之前报道的（萨兰）锰络合物催化的环氧化不同，不仅顺式二取代烯烃的环氧化而且反式和末端烯烃的环氧化都观察到高对映选择性。此外，该反应具有高度立体定向性，生成的环氧化物没有双键几何结构的异构化。 3．使用(salen)钴(II)配合物实现了高度顺式和对映选择性环丙烷化。这一成果首次实现了环丙烷化中所有可能的立体化学的化学控制。 4．通过使用光学活性三(恶唑啉)铜配合物，在外消旋烯烃烯丙基位置的不对称C-H氧化中可以观察到超过80% ee的高对映选择性。