An efficient approach to isoindolo[2,1-b][2]benzazepines via intramolecular [4+2] cycloaddition of maleic anhydride to 4-α-furyl-4-N-benzylaminobut-1-enes
作者:Fedor I. Zubkov、Ekaterina V. Boltukhina、Konstantin F. Turchin、Alexey V. Varlamov
DOI:10.1016/j.tet.2004.07.008
日期:2004.9
nobut-1-enes with maleic anhydride gave 4-oxo-3-aza-10-oxatricyclo[5.2.1.01,5]dec-8-ene-6-carboxylic acid via amide formation followed by intramolecular Diels–Alder reaction of furan (IMDAF). The cycloaddition proceeded under mild reaction conditions (25 °C) and provided only the exo-adduct in quantitative yield. Treatment of this compound with PPA gave isoindolo[2,1-b][2]benzazepine derivatives via
将4-α-呋喃基-4- N-苄基氨基丁-1-烯与马来酸酐酰化,得到4-氧代-3-氮杂-10-氮杂三环[5.2.1.0 1,5 ] dec-8-烯-6-羧酸通过酰胺形成,然后发生呋喃的分子内Diels-Alder反应(IMDAF)。环加成反应条件温和(25℃),并仅设置下进行外,定量收率-adduct。用PPA处理该化合物通过开环,芳构化和分子内亲电烷基化得到异吲哚并[2,1- b ] [2]苯并ze庚因衍生物。为了扩大反应顺序的范围,7-oxo-5,11b,12,13-tetrahydro-7 H -isoindolo [ 2,1- b] [2]苯并ze庚因-8-羧酸被进一步转化为有用的合成中间体。