由于氢化产物的脱氢重新芳构化和氮原子的中毒作用,多环含氮杂芳族化合物的不对称氢化仍然是一个巨大的挑战。这里,通过在原位用乙酸酐来抑制rearomatization和中毒效果,多环含氮杂的新型铱-催化的对映选择性氢化的氢化产物保护-吡咯并/吲哚并[1,2一]喹喔啉和菲啶-已经成功可以轻松获得高达98%ee的手性二氢吡咯并/吲哚并[1,2- a ]喹喔啉和二氢菲啶。该策略具有广泛的底物范围,易于操作和潜在的医学应用。
Driving Recursive Dehydration by P<sup>III</sup>/P<sup>V</sup> Catalysis: Annulation of Amines and Carboxylic Acids by Sequential C–N and C–C Bond Formation
作者:Morgan Lecomte、Jeffrey M. Lipshultz、Shin-Ho Kim-Lee、Gen Li、Alexander T. Radosevich
DOI:10.1021/jacs.9b06277
日期:2019.8.14
A method for the annulation of amines and carboxylicacids to form pharmaceutically relevant azaheterocycles via organophosphorus PIII/PV redox catalysis is reported. The method employs a phosphetane catalyst together with a mild bromenium oxidant and terminal hydrosilane reductant to drive successive C–N and C–C bond-forming dehydration events via the serial action of a catalytic bromophosphonium
Copper-Catalyzed Synthesis of Alkyl-Substituted Pyrrolo[1,2-a]quinoxalines from 2-(1H-Pyrrol-1-yl)anilines and Alkylboronic Acids
作者:Rulong Yan、Xin Guan
DOI:10.1055/s-0037-1610743
日期:2020.3
A radical pathway for the construction of pyrrolo[1,2-a]quinoxalines by using 2-(1H-pyrrol-1-yl)anilines and alkylboronic acids has been developed. Features of this process include Cu catalysis, readily accessible starting materials, and simple operations. Alkylboronic acids are used for the construction of pyrrolo[1,2-a]quinoxaline derivatives, and the desired products are obtained in moderate yields
Application of α-amino acids for the transition-metal-free synthesis of pyrrolo[1,2-a]quinoxalines
作者:Huanhuan Liu、Feiyu Zhou、Wen Luo、Yuxin Chen、Chenyang Zhang、Chen Ma
DOI:10.1039/c7ob01688c
日期:——
A practical and concise protocol for the efficient synthesis of pyrrolo[1,2-a]quinoxalines from readily available α-amino acids and 2-(1H-pyrrol-1-yl)anilines under transition metal-free conditions has been established. This protocol, which includes the formation of new C–C and C–N bonds, features a wide substrate scope with a broad range of functional group tolerance.
建立了一种实用且简洁的方案,可在无过渡金属的条件下从容易获得的α-氨基酸和2-(1 H-吡咯-1-基)苯胺有效合成吡咯并[1,2- a ]喹喔啉。该协议包括新的C–C和C–N键的形成,具有广泛的底物范围和广泛的官能团耐受性。
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。