novel and efficientone-pot method has been developed for the synthesis of 1-substituted-3,4-dihydro-β-carbolines from tryptamine and a wide variety of carboxylic acids. The reaction was successfully applied to the synthesis of an important alkaloid harmalan as well as dihydro-eudistomin-U. This represents the first case in which 1-propanephosphonic acid cyclic anhydride (T3P®) has been used in the
Mild and Efficient Syntheses of 1-Aryl-3,4-dihydroisoquinolines and 1-Aryl-3,4-dihydro-β-carbolines via Regiospecific β-Eliminations of the Corresponding<i>N</i>-Tosyl-1,2,3,4-tetrahydroisoquinolines and<i>N</i>-Tosyl-1,2,3,4-tetrahydro-β-carbolines
作者:Jing Dong、Xiao-Xin Shi、Jing Xing、Jing-Jing Yan
DOI:10.1080/00397911.2011.568659
日期:2012.10
Treatment of N-tosyl-1-aryl-1,2,3,4-tetrahydro-isoquinolines or N-tosyl-1-aryl-1, 2,3,4-tetrahydro-beta-carbolines with a strong base such as NaOH or KOH at 70 degrees C in dimethylsulfoxide (DMSO) produced 1-aryl-3,4-dihydroisoquinolines or 1-aryl-3,4-dihydro-beta-carbolines in good yields via mild and regiospecific beta-eliminations. A dramatic solvent effect was observed, DMSO was crucial for the reactions. The temperature is also crucial for the reactions and should be kept between 60 and 80 degrees C.