Cu(I)-/Base-Mediated Domino [5 + 3 + 1] Annulation for Highly π-Extended Carbazole Frameworks and DFT Mechanistic Insights
作者:Tej Narayan Poudel、Sangita Karanjit、Hari Datta Khanal、Ramuel John Inductivo Tamargo、Yong Rok Lee
DOI:10.1021/acs.orglett.8b02363
日期:2018.9.21
An efficient synthesis of highly π-extended carbazoles is described via an unexpected domino [5 + 3 + 1] annulation approach. The Cu(I)-/base-promoted reactions of 2-nitrocinnamaldehydes with benzyl cyanides provide diverse benzo[b]carbazoles. The reaction is proposed to proceed via a sequential Michael addition/intramolecular addition of an enol into a nitro group, 6π- electrocyclization, and the
通过意外的多米诺骨牌[5 + 3 +1]环化方法描述了高效π-延伸的咔唑的高效合成方法。2-硝基肉桂醛与苄基氰化物的Cu(I)-/碱促进反应可提供各种苯并[ b ]咔唑。提出该反应是通过将烯醇依次加成到硝基中,分子内加成烯醇,进行6π-电环化和由密度泛函理论计算所支持的最终的氧化芳构化来进行的。一些合成的咔唑在Cu 2+离子的荧光传感中显示出显着的潜力。
Mild Base-Promoted Indole Annulation-Oxidative Cross- Coupling of 2-Nitrocinnamaldehydes with β-Tetralones for 3-Naphthylindole and 3-Naphthylbenzo[<i>g</i>
]indole Fluorophores
作者:Tej Narayan Poudel、Yong Rok Lee
DOI:10.1002/adsc.201601327
日期:2017.5.2
(E)‐3‐(1‐nitronaphthalen‐2‐yl)acrylaldehyde with β‐tetralones for the construction of diverse 3‐naphthylindole and 3‐naphthylbenzo[g]indole fluorophores in moderate to good yields. This unique annulation reaction proceeds via the domino Michael addition/hemiacetalization/intramolecular addition of an enolate to a nitro group/decarbonylation/oxidative aromatization sequence under transition metal‐free conditions
本文描述了2-硝基肉桂醛或(E)-3-(1-硝基萘-2-基)丙烯醛与β-四氢萘酮的无过渡金属吲哚环化-氧化交叉偶联,用于构建各种3-萘萘和3萘基苯并[ g ]吲哚荧光团的产率中等至良好。这种独特的环反应进行经由多米诺迈克尔加成/ hemiacetalization /分子内加成的烯醇化物与过渡不含金属的条件下硝基/脱羰/氧化芳构化序列,而无需使用外部还原剂和氧化剂的。通过评估合成的3-萘并吲哚和3-萘基苯并[ g]的光物理性质,也证明了该方案的合成效用。]吲哚衍生物。