Design of new reactions using N-Heterocyclic carbenes as organocatalysts

N-杂环卡宾作为有机催化剂的新反应设计

• 批准号: 341683-2010
• 负责人: Gravel, Michel
• 金额: $ 2.91万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=595463
• 关键词: Design; new; reactions; using; Heterocyclic

Due to their unique properties, N-heterocyclic carbenes (NHCs) have attracted a lot of attention from the chemistry community. Being powerful electron donors, they have rapidly established themselves as an important class of ligands for transition metals. Moreover, they can also act as catalysts in the absence of transition metals. Common to most reactions that are accelerated by NHCs is the reversal of the normal reactivity of aldehydes. These functional groups, which usually react as electrophiles (electron-acceptors), become nucleophiles (electron-donors) in the catalyzed process. Despite this unique property of reactivity reversal, NHCs have only recently been applied to a rapidly increasing number of hitherto unknown reactions. Our own efforts in this area have focused on novel ring expansion reactions and on the development of domino reactions initiated by NHCs. This proposal details four new directions we will pursue over the next five years. New domino Diels-Alder and Stetter reactions will be designed based on the concept of reactivity reversal, and more efficient catalysts will be developed. Nucleophilic catalysis, a less-explored mode of reactivity for NHCs will also be explored. These advances will be applied to the synthesis of biologically active natural products and their analogues.

由于其独特的特性，N-杂环卡宾斯（NHC）吸引了化学界的很多关注。作为强大的电子捐助者，他们迅速将自己确立为过渡金属的重要配体。此外，在没有过渡金属的情况下，它们也可以充当催化剂。大多数由NHC加速的反应共有的是醛正常反应性的逆转。这些官能团在催化的过程中通常会反应为电泳（电子受体），成为亲核试剂（电子单位）。尽管反应逆转了这种独特的特性，但直到最近才将NHC应用于迄今未知反应的迅速增加。我们自己在这一领域的努力集中在新的环反应和NHC发起的多米诺反应的发展上。该提案详细介绍了未来五年我们将寻求的四个新指示。将根据反应逆转的概念设计新的Domino Diels-Alder和Stetter反应，并将开发更有效的催化剂。还将探讨亲核催化，NHC的反​​应性较少。这些进步将应用于生物活性天然产物及其类似物的合成。