权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

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的反应是必不可少的。基于对控制分子间反应因素的新认识，我们开发了各种新的立体控制反应。(1)金属salen配合物的研究金属salen配合物的X-射线结构分析表明，salen配体的构象受到弱键相互作用如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。利用这些知识，首次实现了高顺式和对映选择性的环丙烷化。此外，还介绍了新型的光活化不对称催化剂，并利用这些配合物，发展了以分子氧为末端氧化剂的催化不对称氧化反应。(2)无环立体控制的新方法--使用新的铝和硼烷试剂进行立体特异性和区域选择性的环氧开环， ...更多信息 nt构建连续的不对称中心。手性季碳的高效构建也得到了发展。以这些反应为关键步骤，以高度直接的方式合成了各种复杂结构的天然产物。(3)基于烯醇化物结构动态手性的不对称诱导在没有任何外部手性源的情况下，以对映体特异性的方式实现了光学活性α-氨基酸的直接α-烷基化。新引入的亲核催化剂承载对氨基吡啶部分，使高度对映体区分酰化。观察到的选择性的起源归因于对映体选择性加速。(4)立体选择性合成糖类中的过渡金属催化剂过渡金属催化剂可有效地从保护和未保护的葡萄糖醛合成各种糖类衍生物。(5)内消旋二醇的去对称化及正碳离子手性记忆以手性二溴化联萘基锡为催化剂，通过单酰化反应有效地实现了内消旋二醇的不对称去对称化。在没有任何外部手性源的情况下，光学活性的α-氨基酸通过相应的酰基阳离子转化为光学活性的缩醛胺。这些结果揭示了在通过正碳中间体进行的反应中可以观察到手性记忆。少