Exploiting Chalcogen-Containing Compounds in Donor-Acceptor Cyclopropane and Cyclobutane Chemistry: Access to Four- to Nine-Membered Heterocycles

在供体-受体环丙烷和环丁烷化学中开发含硫化合物：获得四至九元杂环

• 批准号: 457026728
• 负责人: Professor Dr. Daniel B. Werz
• 金额: --
• 依托单位: Institut für Organische Chemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/457026728?language=en
• 关键词: Exploiting; Chalcogen; Containing; Compounds; Donor

In this project, reactions of donor-acceptor cyclopropanes and cyclobutanes with chalcogen-containing compounds will be investigated. Previous work by the group has shown that their high nucleophilicity is ideally suited to initiate ring opening and cycloaddition reactions of these polarized three-membered rings.In the first sub-project, donor-acceptor cyclopropanes are to be expanded into the corresponding four-membered rings under Lewis acid catalysis by inserting a chalcogen atom (S or Se). Reagents that not only contain a nucleophilic chalcogen but also carry a corresponding leaving group on the chalcogen (e.g. thiosulfonates, RSeSeLi etc.) are to serve as chalcogen carriers. A slightly modified reaction design should also allow the insertion of two chalcogens, be they the same or different, into the corresponding five-membered rings with endo-dichalcogenide subunits. Similar reactions should be carried out on the slightly less strained donor-acceptor cyclobutanes in order to arrive at analogous five- and six-membered rings containing chalcogens. With the aid of chiral ligands that complex the Lewis acid, some of these transformations should also be carried out with a dynamic kinetic resolution.The second subproject is devoted to (3+4) -, (3+5) - and (3+6)-cycloadditions of donor-acceptor cyclopropanes with four, five and six atomic components to build seven-, eight- and nine-membered ring systems. In order to obtain sulfur-containing seven-membered rings, benzothietes as a 4-atom component are to be reacted with the polarized three-membered rings under Lewis acid catalysis. The synthesis of eight-membered rings based on the cyclopropanes is to be carried out by means of synergistic catalysis. Vinyl-substituted epoxides, thiiranes and also aziridines as 5-atom components are to be activated by means of Pd catalysis and reacted with the three-membered rings activated by a Lewis acid. Similar reactions starting from vinyl-substituted oxetanes, thietanes and azetidines as 6 atom components should allow access to nine-membered ring systems. The enantioselectivity of the reactions could be controlled by means of chiral ligands on the Lewis acid as well as on the Pd to give a matched or mismatched case.

在本计画中，将研究给体-受体环丙烷及环丁烷与含硫族化合物的反应。在第一个子项目中，给体-受体环丙烷在刘易斯酸催化下，通过引入硫族元素（S或Se），被扩成相应的四元环。不仅含有亲核硫族元素，而且在硫族元素上携带相应离去基团的试剂（例如硫代磺酸盐、RSeSeLi等）用作硫族载体。稍微修改的反应设计也应该允许将两个硫属元素（无论它们是相同的还是不同的）插入到具有内二硫属元素亚基的相应的五元环中。类似的反应应该在张力稍小的给体-受体环丁烷上进行，以得到类似的含有硫属元素的五元和六元环。第二个子项目致力于四、五和六原子环丙烷的（3+4）-、（3+5）-和（3+6）-环加成反应，构建七、八和九元环体系。为了获得含硫的七元环，苯并噻吩作为4原子组分在刘易斯酸催化下与极化的三元环反应。基于环丙烷的八元环的合成通过协同催化进行。作为5原子组分的乙烯基取代的环氧化物、硫杂环丙烷以及氮杂环丙烷通过Pd催化剂活化并与通过刘易斯酸活化的三元环反应。从乙烯基取代的氧杂环丁烷、硫杂环丁烷和氮杂环丁烷作为6个原子组分开始的类似反应应该允许获得九元环体系。反应的对映选择性可以通过在刘易斯酸和Pd上的手性配体来控制，以得到匹配或错配的情况。