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.
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。
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。
TMP–Magnesium and TMP–Zinc Bases for the Regioselective Metalation of the Cinnoline Scaffold
A regioselective functionalization of cinnolines in positions 3 and 8 using metalations has been developed. This involves either the use of a frustrated Lewis pair consisting of BF3 center dot Et2O and TMP2Mg center dot 2LiCl or the in situ generated base TMP2Zn center dot 2MgCl(2)center dot 2LiCl. Successive metalations allow the preparation of 3,8-disubstituted cinnolines. Various functionalizations by acylation, allylation, and cross-coupling reactions with aryl halides or alkenyl iodides were carried out successfully.