Helically chiral polyisocyanates and polyquinoxalines as organocatalysts

作为有机催化剂的螺旋手性多异氰酸酯和聚喹喔啉

• 批准号: 5451720
• 负责人: Professor Dr. Michael Reggelin
• 金额: --
• 依托单位: Arbeitsgruppe Organische Chemie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2005
• 资助国家: 德国
• 起止时间: 2004-12-31 至 2008-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5451720?language=en
• 关键词: Helically; chiral; polyisocyanates; polyquinoxalines; organocatalysts

The goal of our work is to develop and to apply helically chiral polymers as organocatalysts. At the same time the polymer should not only offer process-related advantages if compared to low molecular weight systems, but it should be a carrier of function. Towards this end organocatalytically active units were incorporated into monomers in such a way that, after polymerisation, their microenvironments get uniform and influenced by the chirality of the polymer backbone. Therefore, the configurational stability of the polymer and an efficient chirality transfer from the backbone to the catalytically active sites is of prime interest. Based on these central demands we decided to use polyisocyanates, polyquinoxalines and, as a new class of polymers, polyguanidines. With these polymers we intend to solve the problem of chirality transfer by backbone mediated asymmetric induction of chiral axes in lateral biaryl units. In case of the polyguanidines the helically chiral backbone itself may serve as a catalytically active site. From that, applications in organocatalysis unfold which rely on axially chiral Brønstedt-acids/bases or axially chiral nucleophiles. Moreover, the poyguanidines may be used as "ACDC"-catalysts with reversed polarity.

我们工作的目标是开发和应用螺旋手性聚合物作为有机催化剂。同时，与低分子量体系相比，聚合物不仅应该提供与工艺相关的优势，而且应该成为功能载体。为此，有机催化活性单元被引入单体中，聚合后，它们的微环境变得均匀并受到聚合物主链手性的影响。因此，聚合物的构型稳定性和从主链到催化活性位点的有效手性转移是首要关注的。基于这些核心需求，我们决定使用多异氰酸酯、聚喹喔啉以及作为新型聚合物的聚胍。利用这些聚合物，我们打算通过侧联芳基单元中主链介导的手性轴的不对称诱导来解决手性转移问题。在聚胍的情况下，螺旋手性主链本身可以充当催化活性位点。由此，依赖于轴向手性布伦斯泰特酸/碱或轴向手性亲核试剂的有机催化应用展开。此外，聚胍可以用作具有相反极性的“ACDC”催化剂。