权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

A New Family of Powerful Asymmetric Bifunctional Organocatalysts and their Reactions

一类新的强大的不对称双功能有机催化剂及其反应

基本信息

批准号：
EP/D04961X/1
负责人：
Darren Dixon
金额：
$ 29.35万
依托单位：
University of Manchester
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2006
资助国家：
英国
起止时间：
2006 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FD04961X%2F1
关键词：
New Family Powerful Asymmetric Bifunctional

项目摘要

Certain organic molecules have non-flat 3 dimensional structures which have the inherent property of not being superimposable on their own mirror images. Such a molecule is said to be chiral and the two mirror images are known as enantiomers. These enantiomers behave identically in nearly all situations except when placed in a chiral environment like those found inside biological systems, such as cells, receptors and enzymes. Accordingly one enantiomer of a bioactive chiral compound may elicit very different biological responses with sometimes catastrophic consequences. As a result, chemists have been seeking to discover the perfect reaction that will allow the creation (or synthesis) of such chiral compounds as single enantiomers, not mixtures of them. Chiral compounds may be synthesised by adding one compound to another 'flat' compound such as one containing a carbon-carbon double bond (or alkene), a carbon-nitrogen double bond (or imine), a carbon-oxygen double bond (aldehyde or ketone). The addition reaction destroys the planarity and results in the chiral product, but as addition to each face of the alkene is equally likely, an equal amount of both enantiomers is formed (a racemic mixture). Influencing the reaction to lead to a predominance of one enantiomer (known as asymmetric synthesis) is possible by using additional external chiral reagents or catalysts. These catalysts often affiliate with the flat substrate and prevent or promote, to some extent, an addition reaction of a reagent to one or other of the faces of the alkene, imine or aldehyde. In this proposal we wish to build on some preliminary studies, which have shown that a new type of chiral bifunctional catalyst can simultaneously activate the substrate and reagent and facilitate an efficient reaction between them. This enzyme-like process allows the selective formation of the product as predominantly one enantiomer. We now wish to explore the potential and scope of this chemistry by creating a large family of related catalysts to promote new and important types of reaction with excellent enantiocontrol and apply the findings in the synthesis of biologically active compounds. As the numbers of substrates and reagents amenable to this type of catalysis is large, the potential number of new reactions to be discovered is enormous. Fortunately, the design of our system allows for easy chemical modification and hence simple coarse or fine tuning of the catalyst's structure and reactivity profile. This will ultimately allow one particular catalyst to be matched to a given reagent/substrate pair and facilitate bond formation with high enantiocontrol.Unlike many other efficient chiral catalysts in the literature this family benefits from being made of purely organic materials and is free from metal ions. This makes them easy to synthesise, easy to handle, cheap and less toxic than their metal ion counterparts. Accordingly these new environmentally friendly catalysts and their reactions will be of great value to chemists in industry and academia alike.

某些有机分子具有非平坦的3维结构，其具有不能在其自身镜像上重叠的固有性质。这样的分子被认为是手性的，两个镜像被称为对映体。这些对映异构体在几乎所有情况下都表现相同，除了当放置在生物系统（如细胞，受体和酶）内部的手性环境中时。因此，生物活性手性化合物的一种对映异构体可能引起非常不同的生物反应，有时具有灾难性的后果。因此，化学家们一直在寻求发现完美的反应，以允许产生（或合成）这种手性化合物作为单一的对映异构体，而不是它们的混合物。手性化合物可以通过将一种化合物添加到另一种“扁平”化合物中来合成，例如含有碳-碳双键（或烯）、碳-氮双键（或亚胺）、碳-氧双键（醛或酮）的化合物。加成反应破坏了平面性并产生手性产物，但由于加成到烯烃的每个面上的可能性相同，因此形成了等量的两种对映异构体（外消旋混合物）。通过使用额外的外部手性试剂或催化剂，可以影响反应以导致一种对映异构体占优势（称为不对称合成）。这些催化剂通常附着于平坦的基底，并在一定程度上防止或促进试剂与烯烃、亚胺或醛的一个或另一个面的加成反应。在这个提议中，我们希望建立在一些初步的研究，这表明，一种新型的手性双功能催化剂可以同时激活底物和试剂，并促进它们之间的有效反应。这种酶样过程允许选择性地形成主要作为一种对映体的产物。我们现在希望探索这种化学的潜力和范围，通过创建一个大家族的相关催化剂，以促进新的和重要的类型的反应，具有良好的对映体控制和应用的研究结果在生物活性化合物的合成。由于适合这种类型催化的底物和试剂的数量很大，待发现的新反应的潜在数量是巨大的。幸运的是，我们的系统的设计允许容易的化学改性，因此简单的粗或微调催化剂的结构和反应性。这将最终允许一个特定的催化剂被匹配到一个给定的试剂/底物对，并促进键的形成与高enantiologicalcontrol. Different许多其他有效的手性催化剂在文献中，这是受益于由纯有机材料，是免费的金属离子。这使得它们易于合成，易于处理，便宜且毒性低于金属离子。因此，这些新的环境友好的催化剂和它们的反应将是非常有价值的化学家在工业和学术界一样。