Stereocontrol utilizing intermolecular interaction

利用分子间相互作用的立体控制

基本信息

批准号：
10208214
负责人：
KATSUKI Tsutomu
金额：
$ 44.48万
依托单位：
Kyushu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research on Priority Areas (B)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

项目摘要

Dynamic control of intermolecular interaction is indispensable for achieving highly stereocontrolled reactions. We have developed various new stereocontrolled reactions on the basis of new knowledge on the factors controlling intermolecular reactions.(1) Study with metallosalen complexesThe X-ray structural analysis of metallosalen complexes clarified that conformation of the salen ligands is strongly influenced by weak-bond interactions such as OH-π and CH-π interactions and by the presence or absence of a donor ligand. With this knowledge, highly cis- and enantio-selective cyclopropanation was achieved for the first time. Furthermore, new type of asymmetric catalysts activated by photo-irradiation were introduced and, with these complexes, catalytic asymmetric oxidation using molecular oxygen as the terminal oxidant was developed.(2) New methodologies for acyclic stereocontrolStereospecific and regioselective epoxide-ring opening using new aluminum and borane reagents enabled efficie … More nt construction of consecutive asymmetric centers. High efficient construction of chiral quaternary carbons was also developed. With these reactions as key steps, various natural products of complex architectures were synthesized in a highly straightforward manner.(3) Asymmetric induction based on dynamic chirality of enolate structureDirect α-alkylation of optically active α-amino acids was achieved in an enantiospecific manner in the absence of any external chiral sources. Newly introduced nucleophylic catalyst bearing p-aminopyridine moiety enabled highly enantiomer-differentiating acylation. The origin for the observed selectivity was attributed to enantiomer-selective acceleration.(4) Transition metal catalysts in stereoselective carbohydrate synthesisVarious carbohydrate derivatives were synthesized efficiently from protected and unprotected glucals by using transition metal catalysts.(5) Desymmetrization of meso-diols and memory of chirality in carbenium ionAsymmetric desymmetrization of meso-diols was achieved efficiently by mono-acylation using chiral binaphthyltin dibromide as a catalyst. Optically acive α-amino acids were converted into optically active aminals via the corresponding acylinium ions in the absence of any external chiral sources. These results disclosed that memory of chirality can be observed in the reactions proceeding through a carbenium intermediate. Less

分子间相互作用的动态控制对于实现高度立体控制反应是必不可少的。基于对分子间反应控制因素的新认识，我们开发了各种新的立体控制反应。(1)金属allosalen配合物的研究金属allosalen配合物的X射线结构分析阐明了这一点。 salen 配体的构象受到弱键相互作用（例如 OH-π 和 CH-π 相互作用）以及供体配体的存在或不存在的强烈影响。首次实现了高度顺式和对映选择性的环丙烷化反应。此外，还引入了光照射活化的新型不对称催化剂，并利用这些配合物开发了使用分子氧作为末端氧化剂的催化不对称氧化反应。(2) ) 非环状立体控制的新方法使用新的铝和硼烷试剂实现立体特异性和区域选择性环氧化物开环，从而实现高效……更多 nt以这些反应为关键步骤，以高度简单的方式合成了复杂结构的各种天然产物。(3)基于烯醇结构的动态手性的不对称高效诱导。在没有任何外部手性源的情况下，以对映特异性方式实现了光学活性 α-氨基酸的 α-烷基化，新引入的带有对氨基吡啶部分的亲核催化剂高度启用。所观察到的选择性的起源归因于对映体选择性加速。(4)立体选择性碳水化合物合成中的过渡金属催化剂利用过渡金属催化剂，从受保护和未受保护的糖醛酸中有效地合成了各种碳水化合物衍生物。(5)内消旋二醇和碳正离子手性记忆通过以下方法有效实现了内消旋二醇的不对称去对称化使用手性联萘锡二溴化物作为催化剂进行单酰化，在没有任何外部手性源的情况下，通过相应的酰基离子将光学活性α-氨基酸转化为光学活性缩醛胺。这些结果表明，在反应中可以观察到手性记忆。进行碳鎓中间体。