An efficient and convenient iron-catalyzed protocol has been developed for the synthesis of substituted pyrrolo[1,2-a]quinoxalines from 1-(N-arylpyrrol-2-yl)ethanone O-acetyl oximes through N-O bond cleavage and intramolecular directed C-H arylation reactions in acetic acid.
Efficient synthesis of pyrrolo[1,2-a]quinoxalines catalyzed by a Brønsted acid through cleavage of C–C bonds
作者:Caixia Xie、Lei Feng、Wanli Li、Xiaojun Ma、Xinkun Ma、Yihan Liu、Chen Ma
DOI:10.1039/c6ob01401a
日期:——
An efficient and convenient one-pot domino reaction for the direct synthesis of pyrrolo[1,2-a]quinoxalines has been developed. This approach utilizes an imine formation reaction, SEAr reaction and cleavage of C–C bonds catalyzed by a Brønsted acid. β-Diketones and β-keto esters are both well tolerated to give the corresponding products in moderate to excellent yields.
已经开发了用于直接合成吡咯并[1,2- a ]喹喔啉的有效且方便的一锅多米诺反应。该方法利用用于形成亚胺的反应,S È氩反应和裂解由布朗斯台德酸催化的C-C键。β-二酮和β-酮酯均具有良好的耐受性,可以以中等至极好的收率得到相应的产物。
One-Pot Synthesis of Pyrrolo[1,2-<i>a</i>]quinoxaline Derivatives via a Copper-Catalyzed Aerobic Oxidative Domino Reaction
作者:Huanhuan Liu、Tiantian Duan、Zeyuan Zhang、Caixia Xie、Chen Ma
DOI:10.1021/acs.orglett.5b01167
日期:2015.6.19
A copper-catalyzed process for the synthesis of pyrrolo[1,2-a]quinoxalines from readily available α-amino acids and 1-(2-halophenyl)-1H-pyrroles is described. Different functional groups were well tolerated to give the corresponding products.
描述了一种铜催化的方法,该方法由容易获得的α-氨基酸和1-(2-卤代苯基)-1 H-吡咯合成吡咯并[1,2- a ]喹喔啉。不同的官能团具有良好的耐受性,可提供相应的产品。
One-Pot Synthesis of Pyrrolo[1,2-<i>a</i>]quinoxaline Derivatives via Iron-Promoted Aryl Nitro Reduction and Aerobic Oxidation of Alcohols
作者:Maria de Fatima Pereira、Valérie Thiéry
DOI:10.1021/ol302006b
日期:2012.9.21
describe a new one-pot method to synthesize 4,7-substituted pyrrolo[1,2-a]quinoxalines and related heterocyles through a cascade of redox reactions/imine formation/intramolecular cyclization. This procedure tolerates readily available substituted 1-(2-nitrophenyl)pyrrole derivatives and aliphatic or benzylic alcohols as starting materials using iron powder and acidic conditions. This is the first example
在这里,我们描述了一种新的一锅法,通过级联的氧化还原反应/亚胺形成/分子内环化反应来合成4,7-取代的吡咯并[1,2- a ]喹喔啉和相关杂环。该方法耐受使用铁粉和酸性条件容易获得的取代的1-(2-硝基苯基)吡咯衍生物和脂族或苄基醇作为起始原料。这是在一个罐中通过铁介导的芳基硝基还原和酒精的好氧氧化构造N-杂环的第一个例子。
A Green Aerobic Oxidative Synthesis of Pyrrolo[1,2-<i>a</i>]quinoxalines from Simple Alcohols without Metals and Additives
A practical and concise protocol for the efficient preparation of pyrrolo[1,2-a]quinoxalines through a cascade of alcohol oxidation/imine formation/intramolecular cyclization/oxidative dehydrogenation has been established. A series of substituted pyrrolo[1,2-a]quinoxaline derivatives were constructed readily in yields of 53–93% from the cheap primary alcohols by using dioxygen as the terminal oxidant
已经建立了通过级联的醇氧化/亚胺形成/分子内环化/氧化脱氢有效制备吡咯并[1,2- a ]喹喔啉的实用而简洁的方案。通过使用双氧作为末端氧化剂,可以很容易地从廉价的伯醇中制备出一系列取代的吡咯并[1,2- a ]喹喔啉衍生物,产率为53-93%。值得注意的是,无需额外的金属和添加剂这一事实使得这种前所未有的需氧氧化工艺在步骤和原子经济上都非常经济。在标准条件下,用克级合成化合物3aa进一步证明了这种转化的有用性。