Merging Visible-Light Photoredox and Lewis Acid Catalysis for the Intramolecular Aza-Diels-Alder Reaction: Synthesis of Substituted Chromeno[4,3-<i>b</i>
]quinolines and [1,6]Naphthyridines
作者:Wuheng Dong、Yao Yuan、Xiaoshuang Gao、Bei Hu、Xiaomin Xie、Zhaoguo Zhang
DOI:10.1002/cctc.201800192
日期:2018.7.9
Substituted chromeno[4,3‐b]quinolines and [1,6]naphthyridines were achieved by tandem intramolecular aza‐Diels–Alder reaction using a strategy of combination of visible‐light photoredox and Lewis‐acid‐catalysis. This intramolecular aza‐Diels–Alder cycloaddition took place between the in situ generated benzylidene anilines derived from arylamines and salicylaldehyde or 2‐aminoaryl aldehydes bearing
取代的chromeno [4,3- b喹啉和[1,6]萘啶通过分子内氮杂-Diels-Alder反应,采用可见光光氧化还原和路易斯酸催化相结合的策略获得。这种分子内的氮杂-Diels-Alder环加成反应是在原位生成的亚芳基苯胺与芳胺和水杨醛或带有链状烯烃伴侣的2-氨基芳基醛之间进行的,然后进行氧化芳构化,得到目标产物。对氧化芳构化步骤的研究表明,它比环化步骤要快得多。亚胺和路易斯酸的组合,以及好氧条件下光催化剂和路易斯酸在可见光照射下的组合均能有效地实现转化。