Phosphonium Ion-Tethered Secondary Amines for Chemospecific 5-<i>Enolexo</i> Aldol Condensations of 6-Ketoaldehydes
作者:Akash Sugunan、V. M. Aparna、Goreti Rajendar
DOI:10.1021/acs.joc.3c02285
日期:2023.12.15
targets five-membered carbo- and heterocyclic aldehydes, involving unusual aldehydes as donors and ketones as acceptors. Especially, enolizable aryl keto aldehydes and heteroatom-embedded ketoaldehydes exclusively produced cyclized products with our new catalyst, while other catalysts provided predominantly self-aldol or decomposed products. The scope and diversity of the method demonstrated by synthesizing
使用基于脯氨酸的烷基鏻离子催化剂,提出了一种新型且高选择性的 6-酮醛的 5- enolexo - exo - trig醛醇缩合反应。大体积且亲氧的鏻离子在促进动态醛胺形成和激活酮基以进行醇醛加成方面起着至关重要的作用。这种创新方法专门针对五元碳醛和杂环醛,涉及不寻常的醛作为供体,酮作为受体。特别是,烯醇化芳基酮醛和杂原子嵌入酮醛仅用我们的新催化剂产生环化产物,而其他催化剂主要提供自醇醛或分解产物。通过合成不同的甲醛,包括环戊烯、茚、二氢呋喃、苯并呋喃、二氢吡咯、吲哚、噻吩、二氢噻喃和苯并噻喃,证明了该方法的范围和多样性。