Multicomponent Coupling Cyclization Access to Cinnolines via in Situ Generated Diazene with Arynes, and α-Bromo Ketones
作者:Wen-Ming Shu、Jun-Rui Ma、Kai-Lu Zheng、An-Xin Wu
DOI:10.1021/acs.orglett.5b03236
日期:2016.1.15
A transition-metal-freemulticomponent coupling cyclization reaction was explored involvingarynes, tosylhydrazine, and α-bromo ketones. The reaction proceeds via a formal [2 + 2 + 2] cycloaddition, giving access to cinnoline derivatives in moderate yields under mild conditions. Three chemical bonds were formed—two C–N bonds and one C–C bond—in a single step.
A novel method was developed for the construction of biologically active poly-substituted cinnolines from easily accessible hydrazones in good to excellent yields. A simple copper catalyst could efficiently promote C−N bond formation through selective C−H functionalization and dehydrogenative amination. Furthermore, the inert C−Heteroatom (O/F/N) bonds are susceptible to cleavage in high selectivity
开发了一种新颖的方法,用于以易于获得的azo为原料,以良好或优异的产率构建具有生物活性的多取代cinnolines。一个简单的铜催化剂可以通过选择性的CH功能化和脱氢胺化有效地促进C N键的形成。此外,在新开发的好氧环化反应中,惰性C-杂原子(O / F / N)键易于以高选择性裂解,而不是保留完整的替代C-H键。
Intramolecular redox cyclization reaction access to cinnolines from 2-nitrobenzyl alcohol and benzylamine <i>via</i> intermediate 2-nitrosobenzaldehyde
A transition-metal-free intramolecular redox cyclization reaction for the synthesis of cinnolines has been developed from 2-nitrobenzyl alcohol and benzylamine. Mechanistic investigations disclosed the involvement of a key intramolecular redox reaction, followed by condensation, azo isomerization to hydrazone, cyclization, and aromatization to form the desired products. Notably, the formation of intermediate
以 2-硝基苯甲醇和苯甲胺为原料,开发了一种无过渡金属的分子内氧化还原环化反应,用于合成肉啉。机理研究揭示了关键的分子内氧化还原反应的参与,随后是缩合、偶氮异构化为腙、环化和芳构化以形成所需产物。值得注意的是,中间体 2-亚硝基苯甲醛和 ( E )-2-(2-亚苄基肼基) 苯甲醛的形成在这种转化中起着重要作用。
Copper-Catalyzed Aerobic Dehydrogenative Cyclization of N-Methyl-N-phenylhydrazones: Synthesis of Cinnolines
作者:Guangwu Zhang、Jinmin Miao、Yan Zhao、Haibo Ge
DOI:10.1002/anie.201204339
日期:2012.8.13
The title reaction proceeds through an oxidation/cyclization sequence, thus representing the first copper‐catalyzed coupling reaction of hydrazones through a CH bond functionalization process (see scheme; DMF=N,N′‐dimethylformamide, Py=pyridine). The method provides an environmentally friendly and atom‐efficient approach to biologically active cinnoline derivatives.
O 2 占主导地位:标题反应按氧化/环化顺序进行,因此代表through通过CH键官能化过程进行的首次铜copper偶联反应(请参阅示意图; DMF = N,N'-二甲基甲酰胺,Py =吡啶)。该方法为生物活性的cinnoline衍生物提供了一种环境友好且原子效率高的方法。