Preparation of a chiral organocatalyst and their application for asymmetric carbon-carbon bond construction

手性有机催化剂的制备及其在不对称碳-碳键构建中的应用

基本信息

批准号：
16550032
负责人：
TAKABE Kunihiko
金额：
$ 2.3万
依托单位：
Shizuoka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2005
项目状态：
已结题

项目摘要

We have developed a practical synthesis of the chiral lactam as a new chiral building block for a multitude of asymmetric induction. Excellent kinetic resolution of the lactam, followed by racemization of the resolved product provided the chiral lactam in good yield with >99% ee. Chemical transformation of the lactam furnished chiral (-)-epi-lentiginosin in 20% yield in 10 steps with no loss of enantiomeric excess.Convenient synthesis of Pulchellalactam and its related compounds was also accomplished. Total yields of (Z)-Pulchellalactam and (E)-Pulchellalactam were 55% for 5 steps and 43% for 8 steps from commercially available and inexpensive citraconic anhydride, respectivelyChiral phase-transfer catalyzed enantioselective alkylations of tert-butyl glycinate-benzophenone Schiff base were investigated in aqueous media without any organic solvent. Reactions in aqueous media smoothly proceeded to give the desired product in higher yield than under standard liquid-liquid biphasic conditi … More ons. In aqueous media the formation of benzophenone, which was caused by in-situ hydrolysis of Schiff base, was depressed.We have developed direct asymmetric cross-aldol reactions that can be performed in water without addition of organic solvents. A bifunctional catalyst with a long hydrophobic alkyl chain efficiently catalyzed the reactions and afforded the desired aldol products in excellent yield with high enantiomeric excess, even when only an equal molar ratio of the donor and acceptor was used. These results reveal an effective design strategy for the development of aqueous organocatalytic systems.We have developed a direct, asymmetric Michael reaction that can be performed in brine or seawater without addition of organic solvents. A bifunctional catalyst with long hydrophobic alkyl chains efficiently catalyzed Michael reactions and afforded the desired products in excellent yield with high enantiomeric excess, even when only an equal molar ratio of the donor to acceptor was used. Less

我们已经开发了一种新的手性乳胶，作为多种不对称的手性构建块。）在55％和（e） - pulchellalactam的总收率（pulchellalactam）中，pulchellalactam及其相关化合物的特征也达到了55％和43％在没有y有机溶剂的水性中研究了丁烷丁基乙酸苯甲酸 - 苯甲酮Schiff碱的对映选择。这是由Schiff bas的原位液体引起的，我们开发了直接的不对称交叉 - 醛酚反应，而在水中进行的，而无需添加有机溶剂。即使使用捐赠者和受体的相等摩尔比。仅使用捐赠者与受体的比例相等。