Facile Synthesis of 4-Alkyl (and Aryl)-2-aryl-6-diazo-4<i>H</i>- thieno[3,2-<i>b</i>]pyridine-5,7-diones
作者:Dong Joon Lee、Kyongtae Kim
DOI:10.1021/jo049769a
日期:2004.7.1
Treatment of 3-3-alkyl (and aryl)amino-5-arylthieno-2-yl}-2-diazo-3-oxopropanoates 8 with TMSOTf (3 equiv) in the presence of Et3N (6 equiv) in CH2Cl2 for 1 h at room temperature afforded 4-alkyl (and aryl)-2-aryl-6-diazo-4H-thieno[3,2-b]pyridine-5,7-diones 14 in excellent yields. On heating of 14 in the presence of a catalytic amount of Rh-2(CF3CF2CF2CO2)(4) in PhH for 4-10 h at reflux, corresponding ring contraction products, 4-alkyl (and aryl)-5,6-dihydro-4H-thieno[3,2-b]pyrrol-5-ones 16, were produced in good to excellent yields.