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.

由于其独特的性质，N-杂环卡宾（NHC）引起了化学界的广泛关注。作为强大的电子供体，它们已迅速成为一类重要的过渡金属配体。此外，它们还可以在没有过渡金属的情况下充当催化剂。大多数由 NHC 加速的反应的共同点是醛的正常反应性的逆转。这些官能团通常作为亲电子试剂（电子受体）进行反应，在催化过程中变成亲核试剂（电子供体）。尽管具有反应性逆转的独特性质，NHC 直到最近才被应用于数量迅速增加的迄今为止未知的反应。我们在这一领域的努力主要集中在新型扩环反应和 NHC 引发的多米诺骨牌反应的发展上。该提案详细介绍了我们未来五年将追求的四个新方向。新的多米诺骨牌Diels-Alder和Stetter反应将基于反应性逆转的概念进行设计，并将开发更高效的催化剂。还将探索亲核催化，这是 NHC 的一种较少探索的反应模式。这些进展将应用于生物活性天然产物及其类似物的合成。