Stereocontrolled construction of 4,5-dihydropyrrolo[1,2-a]quinoxaline scaffolds via chiral phosphoramidate catalyzed Pictet–Spengler-type reaction
摘要:
An efficient catalytic asymmetric synthesis of 4,5-dihydropyrrolo[1,2-a]quinoxalines has been developed on the basis of the Pictet-Spengler-type condensation of 1-(2-aminophenyl)pyrrole with a wide range of aldehydes. Structurally diverse 4,5-dihydropyrrolo[1,2-a]quinoxaline derivatives were obtained from 1-(2-aminophenyl)pyrrole and both aromatic and aliphatic aldehydes in good yields with moderate to good enantioselectivities upon treatment with chiral phosphoramidate catalyst IVb. (C) 2016 Elsevier Ltd. All rights reserved.
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。
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