Rajapaksa Kumudi J W, Yan Wong Hang, Lee Daesung
Department of Chemistry, University of Illinois at Chicago, 845 W. Taylor St., Chicago, Illinois, 60607, USA.
Chemistry. 2024 Nov 21;30(65):e202403270. doi: 10.1002/chem.202403270. Epub 2024 Nov 5.
We describe novel amine-mediated transformation of alkynyl ketones and amides to generate 2-methylene-2H-pyrans, substituted 3-hydroxy-9H-fluoren-9-ones, and amine-incorporated arenes. These cascade processes are initiated by conjugate addition of secondary amine followed by hydrolysis of the enamine/vinylogous amide intermediates. The product distribution is highly sensitive to the steric and electronic effects of the substituents on both the alkyne moieties, the tether structure connecting them, and the nature of the amine. Alkynyl amide participates in the Alder-ene reaction favorably to generate more reactive allene amide that reacts with amine to generate amine-incorporated arene products. These metal-free cascade reactions are a useful synthetic method that can be exploited for the construction of various hetero- and carbocyclic systems.
我们描述了一种新型的胺介导的炔基酮和酰胺转化反应，可生成2-亚甲基-2H-吡喃、取代的3-羟基-9H-芴-9-酮以及含胺芳烃。这些串联反应由仲胺的共轭加成引发，随后是烯胺/乙烯基酰胺中间体的水解。产物分布对炔基部分上取代基的空间和电子效应、连接它们的连接结构以及胺的性质高度敏感。炔基酰胺有利于参与Alder-ene反应，生成更具反应性的丙二烯酰胺，后者与胺反应生成含胺芳烃产物。这些无金属串联反应是一种有用的合成方法，可用于构建各种杂环和碳环体系。
