I2/DMSO-Promoted Synthesis of Chromeno[4,3-b]quinolines through an Imine Formation/Aza-Diels–Alder/Aromatization Tandem Reaction under Metal-Catalyst- and Photosensitizer-Free Conditions
作者:Vladimir V. Kouznetsov、Angélica Peñaranda Gómez、Carlos E. Puerto Galvis、Mario A. Macías、Cristian Ochoa-Puentes
DOI:10.1055/a-1638-5030
日期:2022.4
A tandem approach was developed for the efficient synthesis of substituted chromeno[4,3-b]quinolines from arylamines and O-cinnamyl salicylaldehydes under metal-catalyst- and photosensitizer-free reaction conditions. Our protocol is based on an inexpensive I2/DMSO system in which molecular iodine first acts as a Lewis acid to promote the formation of the corresponding imine bearing the alkene moiety;
开发了一种串联方法,用于在无金属催化剂和无光敏剂的反应条件下,由芳胺和 O-肉桂基水杨醛有效合成取代的色基 [4,3-b] 喹啉。我们的协议基于廉价的 I2/DMSO 系统,其中分子碘首先充当路易斯酸,以促进带有烯烃部分的相应亚胺的形成;然后,该物种通过催化分子内氮杂-Diels-Alder 环加成反应生成相应的四氢色酚喹啉作为中间体来发挥第二个作用。最后,DMSO 作为氧化剂和溶剂的双重行为在这个阶段被证明是至关重要的,允许 I2 的再生并促进四氢色基喹啉中间体的芳构化,以产生所需的 7-芳基-6H-色基 [4,3-b ]喹啉。