Regioselective Thorpe–Ziegler Cyclization of 3-O-Alkylated Thiophenes; Access to Aminothieno[3,2-b]furans and Aminothieno[3,4-b]furans
作者:Stéphanie Hesse、Charlène Gadais、Gilbert Kirsch
DOI:10.1055/s-0032-1316735
日期:——
Abstract A two-step synthesis of polyfunctionalized aminothieno[3,2-b]furans and aminothieno[3,4-b]furans is described and discussed. It was found that O-alkylated thiophenes bearing electron-withdrawing groups in the ortho-position undergo condensation in the presence of an excess of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). Furthermore, selective condensation on an ortho-nitrile substituent in preference
摘要 描述并讨论了多官能化氨基硫代[3,2- b ]呋喃和氨基硫代[3,4- b ]呋喃的两步合成。发现在过量的1,8-二氮杂双环[5.4.0]十一烷基-7-烯(DBU)存在下,在邻位带有吸电子基团的O-烷基化噻吩发生缩合。此外,在一个选择性的缩合邻优先于-腈取代基的邻位-酯或邻位的观察-酮的取代基。 描述并讨论了多官能化氨基硫代[3,2- b ]呋喃和氨基硫代[3,4- b ]呋喃的两步合成。发现在过量的1,8-二氮杂双环[5.4.0]十一烷基-7-烯(DBU)存在下,在邻位带有吸电子基团的O-烷基化噻吩发生缩合。此外,在一个选择性的缩合邻优先于-腈取代基的邻位-酯或邻位的观察-酮的取代基。