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.
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
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.
Tailored SnO2@MWCNTs efficient and recyclable nano-catalyst for selective synthesis of 4, 5-dihydropyrrolo [1, 2-a] quinoxalines via Pictet–Spengler reaction
作者:Sushil R. Mathapati、Ravindra C. Alange、C. B. Sherin Mol、Sambhaji S. Bhande、Arvind H. Jadhav
DOI:10.1007/s11164-022-04852-0
日期:2022.12
investigated and discussed in detail. The protocol displayed high tolerance to different functionalities with respect to different substituted aromatic aldehydes to form quinoxalinederivatives in efficient way and gave excellent yield. Plausible reaction mechanistic pathway for the selective formation of quinoxaline over SnO2@MWCNTs is also proposed. It is believed that high dispersion of SnO2 over MWCNTs