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Development of open chemical systems constantly producing one of the enantiomers of chiral products

开发开放化学系统，不断生产手性产品的对映体之一

基本信息

批准号：
14540548
负责人：
ASAKURA Kouichi
金额：
$ 2.37万
依托单位：
Keio University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14540548/
关键词：
Chiral symmetry breaking Chiral autocatalysis Open chemical system Crystal growth front 1,1'-Binaphthyl Asymmetric amplification Non-linear kinetic model Michaelis-Menten type intermediate 1,1-ビナフチルキラル自触媒系光学純度速度論解析 PDB

项目摘要

Homochirality in biomolecules in nature can be regarded as a chiral symmetiy breaking, a dissipative structure, that is a self-orgnization in nonequilibrium open system as a result of growth of fluctuation by irreversible dissipative processes. The kinetic model for chiral symmetry breaking was proposed about 20 years ago (D.K.Kondepudi, G.W.Nelson. Nature, 1985, 314, 438). The real chemcal system in which spontaneous generation of homochirality by following the model, hewever, has not been realized.Crystallization of 1,1'-binaphthyl from its racemic melt was studied. Chiral crystal of 1,1'-binaphthyl is crystallized when the temperature is in the range from 145 to 158℃, and the crystallization process is chirally autocatalytic (D.K.Kondepudi, J.Laudadio, K.Asakura, J.Am.Chem.Soc., 1999, 121, 1448). Temperature distribution in crystallization system was monitored and the structure of the crystal phase thus generated was characterized by X-ray diffraction. Enantiomeric excess of the cry … More stal phase generated when the temperature of the growth front was in the range from 145 to 158℃ was bimodal and its average was about 60%. The spontaneous generation of chiral asymmetry was identified as the chiral symmetry breaking in the growth front. A kinetic model to explain the mechanism was developed to investigate the condition at which racemic state becomes unstable to lead to generate homochiral state.A mechanism of asymmetric amplification, chemical reaction in which enantiomeric excess of a product is higher than that of chiral auxiliary for catalyst, was also investigated. The ultimate goal of this research is to achieve chiral symmetry breaking by following Kondepudi & Nelson's model in organic chemical reaction system. The chirally autocatalytic reaction found by Soai et al. is one of the candidate reaction (K.Soai, et al., Nature, 1995, 378, 767) Similar compounds are used for the asymmetric amplification and the chirally autocatalytic reaction. Michaelis-Menten type intemediate was found to be generated in the asymmetric amplification. Less

自然界中生物分子的同色性可以看作是一种手征对称性破缺，是一种耗散结构，是非平衡开放系统中涨落增长的不可逆耗散过程的自组织。手性对称性破缺的动力学模型是大约20年前提出的(D.K.Kondesudi，G.W.Nelson)。《自然》，1985,314,438)。在实际的化学体系中，通过遵循Hewever模型自发地产生均一性尚未实现。研究了1，1‘-联萘的外消旋熔体结晶。1，1‘-联萘的手性晶体在145~158℃的温度范围内结晶，结晶过程是手性自催化的(D.K.Kondesudi，J.Laudadio，K.Asakura，J.Am.Chem.Soc.，1999,121,1448)。对晶化过程中的温度分布进行了监测，并用X射线衍射仪对晶相结构进行了表征。呐喊…的对映体过量生长前沿温度在14 5~15 8℃范围内产生的Stal相较多，为双峰型，其平均值约为60%。手性不对称的自发产生被认为是生长前沿的手性对称性破缺。建立了一个动力学模型来解释反应机理，研究了外消旋状态变得不稳定而导致同手性状态的条件，并研究了不对称放大反应的机理，即产物的对映体过剩高于催化剂的手性助剂的化学反应。本研究的最终目的是在有机化学反应体系中遵循Kondesudi&Nelson模型实现手性对称性破缺。Soai等人发现的手性自催化反应。是候选反应之一(K.Soai，et al.，Natural，1995,378,767)，类似的化合物被用于不对称扩增和手性自催化反应。在不对称扩增过程中产生了米氏中间体。较少