Chemical Sciences and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram 695019, India.
Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
J Org Chem. 2022 Jun 17;87(12):8017-8027. doi: 10.1021/acs.joc.2c00645. Epub 2022 Jun 6.
A base-mediated annulation of 2-nitrobenzothiophenes with naphthols was realized for the synthesis of hitherto unknown class of heteroacenes, namely benzothieno[2,3-]naphthofurans. By using naphthols with a hydroxyl group positioned at 1st or 2nd position, we could synthesize two positional isomers, benzothieno[2,3-]naphtho[2,1-]furans or benzothieno[2,3-]naphtho[2,3-]furans. The annulation was found to be general with a range of substituted 2-nitrobenzothiophenes and naphthols. This heteroannulation of benzothiophene was extended using a range of phenols affording the corresponding benzothieno[2,3-]benzofurans in moderate yields. The basic photophysical properties of these heteroacenes were evaluated, and we also demonstrated the applicability of this annulation on the gram scale.
实现了 2-硝基苯并噻吩与萘酚的基底介导环化反应，从而合成了迄今未知的杂芳族化合物，即苯并噻吩[2,3-n]萘呋喃。通过使用羟基位于 1 位或 2 位的萘酚，我们可以合成两种位置异构体，即苯并噻吩[2,3-n]萘[2,1-f]呋喃或苯并噻吩[2,3-n]萘[2,3-f]呋喃。该环化反应具有广泛的取代 2-硝基苯并噻吩和萘酚的通用性。使用一系列酚类化合物扩展了苯并噻吩的这种杂环化反应，以中等产率得到相应的苯并噻吩[2,3-b]苯并呋喃。评估了这些杂芳族化合物的基本光物理性质，并且我们还证明了该环化反应在克级规模上的适用性。
