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Asymmetric Hetero-Dinuclear Catalysis via Cooperation of Platinum(II) and Palladium(II) for the Stereoselective Formation of Quaternary Stereocenters

铂(II)和钯(II)合作的不对称异双核催化立体选择性形成四元立构中心

基本信息

批准号：
239918246
负责人：
Professor Dr. René Peters
金额：
--
依托单位：
Institut für Organische Chemie (IOC)
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2013
资助国家：
德国
起止时间：
2012-12-31 至 2016-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/239918246?language=en
关键词：
Asymmetric Hetero Dinuclear Catalysis via

项目摘要

The overall goal of the proposed studies is to understand the interplay of Pt(II) and Pd(II) within a cooperative homochiral bimetallic catalyst system to be able to transfer and apply this mode of action to other related reaction types. The intramolecular cooperation of pallada- and platinacycles should result in the development of catalytic reactions, in which an olefin moiety is face-selectively activated for the attack by a nucleophile, which itself is generated by the catalyst (for instance by C-H acitivation or enolization). The heterobimetallic metallacycles should allow for high reactivity and stereoselectivity by the cooperative activation mode taking advantage from a defined orientation of the substrate molecules at defined positions at the catalytical sites. Pt(II) has been chosen to extend the lifetime of a productive (yet reversible) olefin coordination and thus (depending on the reaction type) to achieve an overall acceleration of the catalytic reactions. The presence of the Pd center shall i.a. accelerate the olefin coordination at Pt by some sort of a chelate effect. The synergistic effect of both metal centers shall be investigated for two different reaction types: (1) the formation of biologically interesting tetrahydrocarbazoles via Friedel-Crafts alkylations (also called hydroarylations) and (2) the regio-, diastereo- and enantioselective formal allylic substitution via an SN2(prime)-mechanism, simultaneously controlling the configuration of the generated stereocenters at the allylic substrate (tertiary center) and at the nucleophile (quaternary center) in a new C-C bond.

所提出的研究的总体目标是了解Pt（II）和Pd（II）在合作的纯手性双金属催化剂系统内的相互作用，以便能够将这种作用模式转移并应用于其他相关的反应类型。钯环和铂环的分子内合作应导致催化反应的发展，其中烯烃部分被亲核试剂面选择性活化，亲核试剂本身由催化剂产生（例如通过C-H活化或烯醇化）。杂环金属杂环应该允许高反应性和立体选择性，通过协同活化模式，利用在催化位点的限定位置处的底物分子的限定取向。选择Pt（II）以延长生产性（但可逆的）烯烃配位的寿命，从而（取决于反应类型）实现催化反应的总体加速。Pd中心的存在应通过某种螯合作用加速烯烃在Pt上的配位。应针对两种不同的反应类型研究两种金属中心的协同效应：（1）通过Friedel-Crafts烷基化反应形成生物学上感兴趣的四氢咔唑（也称为氢化芳基化）和（2）通过SN 2（主）-机理的区域-、非对映-和对映选择性的正式烯丙基取代，同时控制在新的C-C键中的烯丙基底物（叔中心）和亲核体（季中心）处生成的立体中心的构型。