establishment of some acid-acid-catalyzed tandem reactions. Addition of MB to acid-catalyzed reaction system not only allowed the use of some basic amines as substrates, which are generally incompatible with the acid conditions, but also enabled the successful synthesis of many important nitrogen-containing heterocycles, such as β-carbolines, pyridines, and quinazolines, in a straightforward manner.
A practical synthesis of β-carbolines by tetra-n-butylammonium bromide (TBAB)-mediated cycloaromatization reaction of aldehydes with tryptophan derivatives
作者:Zhen Wang、Zhenzhen Yu、Yao Yao、Yakai Zhang、Xuefeng Xiao、Bin Wang
DOI:10.1016/j.cclet.2019.07.001
日期:2019.8
Abstract A mild and efficient nBu4NBr-mediated oxidative cycloaromatization to prepare β-carbolines from readily available tryptophans and aldehydes is described. The reaction is practical and allows the synthesis of β-carbolines on gram-scale. Some of products crystallized from the reaction mixture and were easily removed by filtration, obviating the need for chromatographic separation.