Regioselective synthesis of 3-acylindolizines and benzo- analogues via 1,3-dipolar cycloadditions of N-ylides with maleic anhydride
作者:Yun Liu、Yan Zhang、Yong-Miao Shen、Hong-Wen Hu、Jian-Hua Xu
DOI:10.1039/c000277a
日期:——
regioselectively synthesized by a convenient one pot reaction of the corresponding pyridinium (quinolinium, isoquinolinium) ylide with maleic anhydride (MA) in the presence of the mild oxidant tetrakispyridinecobalt(II) dichromate (TPCD). These reactions proceed via a tandem reaction sequence of 1,3-dipolar cycloaddition of azomethine ylide with MA, anhydride hydrolysis and oxidative bisdecarboxylation
3-Acylindolizines(5a-5f)和它们的苯并类似物1-acylpyrrolo [1,2- a ] quinolines(6a - 6f)和1-acylpyrrolo [2,1- a ] isoquinolines (7a-7i)是通过区域选择性合成的相应的吡啶鎓(喹啉鎓,异喹啉鎓)内酯与马来酸酐 (嘛)在弱氧化剂存在下 四铬吡啶钴(II)重铬酸盐 (TPCD)。这些反应通过偶氮甲meth内酯与1,3,3-偶极环加成的串联反应序列进行嘛, 酐 水解和一级环加合物的氧化双脱羧,然后将二氢吲哚并咪唑脱氢芳构化。 TPCD在反应中同时用作脱羧剂和脱氢剂。这些结果表明TPCD 是用于脂肪族羧酸酯双脱羧的有前途的新试剂。