摘要 我们在本文中描述了一种新型的TEMPO氧铵盐引发的亚胺的Pictet-Spengler反应,该反应是从羰基化合物和含吡咯或吲哚的底物就地产生的,以提供4,5-二氢吡咯并[1,2- a ]喹喔啉或5,6 -二氢吲哚并[1,2- a ]喹喔啉的收率为好至极好。此外,通过使用一当量的氧铵盐的环化-脱氢过程,一锅合成重要的生物学重要的喹喔啉。 我们在本文中描述了一种新型的TEMPO氧铵盐引发的亚胺的Pictet-Spengler反应,该反应是从羰基化合物和含吡咯或吲哚的底物就地产生的,以提供4,5-二氢吡咯并[1,2- a ]喹喔啉或5,6 -二氢吲哚并[1,2- a ]喹喔啉的收率为好至极好。此外,通过使用一当量的氧铵盐的环化-脱氢过程,一锅合成重要的生物学重要的喹喔啉。
and catalytic amounts of acetic acid leads to 4,5-dihydropyrrolo[1,2-a]quinoxalines in high yields. When aliphatic aldehydes were used under the same conditions, a slow oxidation to the corresponding pyrrolo[1,2-a]quinoxalines can occur; the oxidation can be avoided by preparing in situ the 5-acetyl derivatives of the 4,5-dihydropyrrolo[1,2-a]quinoxalines.
1-(2-氨基苯基)吡咯与芳族或杂芳族醛在乙醇中的反应和催化量的乙酸反应可高产率地产生4,5-二氢吡咯并[1,2- a ]喹喔啉。在相同条件下使用脂族醛时,可能会缓慢氧化为相应的吡咯并[1,2- a ]喹喔啉;通过原位制备4,5-二氢吡咯并[1,2- a ]喹喔啉的5-乙酰基衍生物可以避免氧化。
Lewis Acid-Catalyzed Selective Synthesis of Diversely Substituted Indolo- and Pyrrolo[1,2-a]quinoxalines and Quinoxalinones by Modified Pictet-Spengler Reaction
作者:Akhilesh K. Verma、Rajeev R. Jha、V. Kasi Sankar、Trapti Aggarwal、Rajendra P. Singh、Ramesh Chandra
DOI:10.1002/ejoc.201101013
日期:2011.12
An efficient tandem process for the selectivesynthesis of 1,2-annulated α-fused quinoxalines using benzotriazole methodology by a modifiedPictet–Spenglerreaction is described. The approach involves the reaction of arylamines 4 with aromatic aldehydes 5 to furnish 6-endo-dig-cyclized products. Dihydroquinoxalines 6 were selectively obtained by using AlCl3 in tetrahydrofuran (THF) at room temperature
Highly selective synthesis of mono- and bis-4,5-dihydropyrrolo[1,2-a]quinoxalines catalyzed by sustainable supported acidic ionic liquid in water media
AbstractPreparation of substituted as well as the selective synthesis of mono- and bis-4,5-dihydropyrrolo[1,2-a]quinoxalines using a highly efficient, sustainable, and reusable supported acidic ionic liquid is reported. The reaction method is ecofriendly and has the advantages of mild conditions, green solvent (H2O), short reaction times, and a reusable acidic catalyst. Graphical abstract
摘要报道了使用高效,可持续和可重复使用的负载型酸性离子液体制备取代的以及选择性合成单和双-4,5-二氢吡咯并[1,2- a ]喹喔啉。该反应方法是环境友好的,并且具有条件温和,绿色溶剂(H 2 O),反应时间短和可重复使用的酸性催化剂的优点。 图形概要