1360546-76-4Relevant academic research and scientific papers
Metal-Free Synthesis of Pyrrolo[1,2- a ]quinoxalines Mediated by TEMPO Oxoammonium Salts
Huo, Heng-Rui,Tang, Xiang-Ying,Gong, Yue-Fa
, p. 2727 - 2740 (2018/06/20)
We herein describe a novel TEMPO oxoammonium salt initiated Pictet-Spengler reaction of imines, generated in situ from carbonyl compounds and pyrrole- or indole-containing substrates, to afford 4,5-dihydropyrrolo[1,2- a ]quinoxalines or 5,6-dihydroindolo[1,2- a ]quina-oxalines in good to excellent yields. Moreover, a one-pot synthesis of a biologically important quinoxaline is achieved via a cyclization-dehydrogenation process using one equivalent of the oxoammonium salt.
Lewis acid-catalyzed selective synthesis of diversely substituted indolo-and pyrrolo[1,2-a]quinoxalines and quinoxalinones by modified pictet-spengler reaction
Verma, Akhilesh K.,Jha, Rajeev R.,Sankar, V. Kasi,Aggarwal, Trapti,Singh, Rajendra P.,Chandra, Ramesh
experimental part, p. 6998 - 7010 (2012/01/06)
An efficient tandem process for the selective synthesis of 1,2-annulated α-fused quinoxalines using benzotriazole methodology by a modified Pictet-Spengler reaction 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 for two hours. However, after ten hours, quinoxalines 7 were obtained exclusively in excellent yields. A series of biologically important fluoro-and piperazenyl-substituted quinoxalines were also synthesized. This developed methodology also provides access to a novel tandem synthesis of quinoxalinones 9.
