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: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=549452
• 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.

N-杂环卡宾化合物由于其独特的性质，引起了化学界的广泛关注。作为强有力的电子给体，它们迅速成为过渡金属的一类重要配体。此外，它们还可以在不存在过渡金属的情况下充当催化剂。NHC加速的大多数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体（电子受体）反应，在催化过程中成为亲核体（电子供体）。尽管有这种独特的反应性逆转特性，NHC只是最近才被应用于数量迅速增加的迄今为止未知的反应。我们自己在这方面的努力集中在新的扩环反应和发展的多米诺骨牌反应引发的NHC。该提案详细说明了我们在未来五年将追求的四个新方向。新的多米诺Diels-Alder和Stetter反应将根据反应性逆转的概念设计，并将开发更有效的催化剂。亲核催化，一个较少探索的NHC反应模式也将进行探索。这些进展将应用于生物活性天然产物及其类似物的合成。