NHC-Ligands for Olefin Metathesis

该项目旨在合成新的N-杂环卡宾，以获得用于各种烯烃复分解反应的改进催化剂。已知N，N-二芳基咪唑亚基构成一类非常有利的配体，因此我们打算通过合成拓宽此类配体用于催化转化的范围。基于新的催化剂，该项目将主要集中在开发与萜烯的交叉复分解反应以及立体选择性烯烃复分解反应催化剂的合成和应用。角鲨烯和天然橡胶将转化为低分子量萜烯，这可能构成有机合成的宝贵基石。具有三蝶烯和五蝶烯单元的蝶烯-NHC配体的合成，其芳基翼在相应N-芳基的平面下方和上方延伸得很远，应导致配体，其中围绕相应金属的某些区域被封闭，因此可能实现立体选择性催化。

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.