NHC-Ligands for Olefin Metathesis

该项目旨在合成新的n -杂环羰基化合物，以获得用于各种烯烃复分解反应的改进催化剂。已知N，N-二芳基咪唑（in）吡啶是一类非常有利的配体，因此我们打算在合成上扩大这类配体在催化转化中的应用范围。本项目将以新型催化剂为基础，重点研究萜烯交叉复分解反应和立体选择性烯烃复分解反应催化剂的合成与应用。角鲨烯和天然橡胶将被转化为低分子量的萜烯，这可能构成有机合成的宝贵基石。含有三tytyene和penttytyene单元的iptyene - nhc配体的合成，其芳基翼延伸远低于或高于各自的n -芳基平面，这将导致配体中各自金属周围的某些区域被阻断，从而可能实现立体选择催化。

The project aims towards synthesizing new N-heterocyclic carbenes to obtain improved catalysts for the application in various olefin metathesis reactions. N,N-Diarylimidazol(in)ylidene are known to constitute a very favorable class of ligands and we therefore intend to synthetically broaden the scope of such ligands in their use for catalytic transformation. Based on new catalysts the project will mainly focus on the development of cross metathesis reactions with terpenes and on the synthesis and application of catalysts for stereoselective olefin metathesis reactions. Squalene and natural rubber are to be converted into low molecular weight terpenes, which might constitute valuable building blocks for organic synthesis. The synthesis of iptycene-NHC ligands with triptycene and pentiptycene units, whose aryl wings extend far below and above the plane of the respective N-aryl group should lead to ligands, in which certain areas around the respective metal are blocked and thus might enable stereoselective catalysis.