High Oxidation State Tungsten Oxo, Tungsten Thio, and Tungsten Imido Alkylidene NHC Complexes for Olefin Metathesis of Functional Olefins

高氧化态氧化钨、硫代钨和亚氨基亚烷基钨 NHC 配合物用于功能性烯烃的烯烃复分解

基本信息

批准号：
319116190
负责人：
Professor Dr. Michael R. Buchmeiser
金额：
--
依托单位：
Lehrstuhl für Makromolekulare Stoffe und Faserchemie
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2016
资助国家：
德国
起止时间：
2015-12-31 至 2019-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/319116190?language=en
关键词：
Oxidation State Tungsten Oxo Thio

项目摘要

Both neutral and cationic high-oxidation state tungsten oxo, tungsten thio and tungsten imido alkylidene N-heterocyclic carbene (NHC) complexes of the general formula W(E)(CHCMe2R)(NHC)X2 and [W(E)(CHCMe2R)(NHC)X+ Y-] (E = O, S, NR1; R1 = tBu, Ad, Ar; R = CH3, Ph) shall be prepared. Besides of the substitution of oxygen by S and NR1, the use of different NHCs with substantially different sigma-donor capability shall be investigated. Variations shall include but not be limited to NHC = imidazol-2-ylidenes, imidazolidin-2-ylidenes, cyclic alkyl aminocarbenes (CAACs), cyclic (amino)(aryl)carbenes (CAArCs), tetrazolin-2-ylidenes, pyrazolin-4-ylidenes, triazol-2-ylidenes and R6-carbodiphosphoranes (R = alkyl, phenyl). In terms of the anionic X-ligand, both weak and stronger sigma-donor ligands such as (fluorinated) alkoxides, thiolates, thiophenolates and iodide shall be used. This will allow identifying the influence of the E-, NHC- and the X-ligand on both the reactivity and functional group tolerance in various olefin metathesis reactions. These will comprise of ring-closing metathesis (RCM), homo-metathesis, cross-metathesis (CM), self-metathesis (SM), ring-opening cross-metathesis (ROCM) and ene-diyne metathesis reactions as well as of ring-opening metathesis polymerization (ROMP). In HM, SM, CM, ene-diyne and ROCM reactions, but also in ROMP, special attention will be devoted to stereoselectivity, an issue that shall be addressed with the aid of novel ansa-type NHCs and NHCs with different sigma-donor capability. In particular, the issue of Z-selectivity shall be addressed and the structure (TB vs. SP) of the tungstacyclobutane shall be elucidated. The work proposed here is not only intended to broaden the understanding about tungsten oxo/thio/imido alkylidene NHC complexes, but also to offer a new class of functional group tolerant, highly active, stereo- and regioselective catalysts for olefin metathesis-based C-C coupling reactions. Last but not least, we will apply the elaborated concept to the synthesis of highly stereoregular polymers via ROMP.

中性和阳离子高氧化态氧化钨、硫代钨和亚氨基亚烷基钨 N-杂环卡宾 (NHC) 配合物，通式为 W(E)(CHCMe2R)(NHC)X2 和 [W(E)(CHCMe2R)( NHC)X+ Y-] (E = O、S、NR1；R1 = tBu、Ad、Ar； R = CH3, Ph) 应准备好。除了用 S 和 NR1 取代氧外，还应研究使用具有显着不同 σ 供体能力的不同 NHC。变体应包括但不限于 NHC = 咪唑-2-亚基、咪唑烷-2-亚基、环烷基氨基卡宾 (CAAC)、环（氨基）（芳基）卡宾 (CAArCs)、四唑啉-2-亚基、吡唑啉-4 -亚基、三唑-2-亚基和 R6-碳二正膦（R = 烷基、苯基）。就阴离子X配体而言，应使用弱和强的σ供体配体，例如（氟化）醇盐、硫醇盐、苯硫酚盐和碘化物。这将允许确定 E-、NHC- 和 X-配体对各种烯烃复分解反应中的反应性和官能团耐受性的影响。这些将包括闭环复分解（RCM）、均复分解、交叉复分解（CM）、自复分解（SM）、开环交叉复分解（ROCM）和烯-二炔复分解反应以及环-开放复分解聚合(ROMP)。在 HM、SM、CM、烯二炔和 ROCM 反应以及 ROMP 中，将特别关注立体选择性，这一问题应借助新型 ansa 型 NHC 和具有不同 Sigma 供体能力的 NHC 来解决。特别是，应解决 Z 选择性问题，并阐明环丁钨钨的结构（TB 与 SP）。这里提出的工作不仅旨在拓宽对钨氧代/硫代/亚氨基亚烷基NHC配合物的理解，而且还为基于烯烃复分解的C-C偶联提供一类新的官能团耐受性、高活性、立体和区域选择性催化剂反应。最后但并非最不重要的一点是，我们将把详细的概念应用于通过 ROMP 合成高度立构规整的聚合物。