Bioorganische Chemie, Institut für Chemie, Universität Hohenheim, Garbenstrasse 30, D-70599 Stuttgart, Germany.
J Org Chem. 2012 Sep 21;77(18):7793-803. doi: 10.1021/jo3014275. Epub 2012 Sep 4.
The Cu(I)-catalyzed reaction of 1-bromo-2-iodobenzenes and other 1,2-dihalobenzenes with 1,3-cyclohexanediones in DMF at 130 °C using Cs(2)CO(3) as a base and pivalic acid as an additive selectively delivers 3,4-dihydrodibenzo[b,d]furan-1(2H)-ones with yields ranging from 47 to 83%. The highly regioselective domino process is based on an intermolecular Ullmann-type C-arylation followed by an intramolecular Ullmann-type O-arylation. Substituted products are accessible by employing substituted 1-bromo-2-iodobenzenes and substituted 1,3-cyclohexanediones as substrates. Reaction with an acyclic 1,3-diketone yields the corresponding benzo[b]furan.
在 DMF 中，使用 Cs(2)CO(3)作为碱，并用特戊酸作为添加剂，在 130°C 下，1-溴-2-碘苯和其他 1,2-二卤代苯与 1,3-环己二酮反应，选择性地以 47%至 83%的产率得到 3,4-二氢二苯并[b,d]呋喃-1(2H)-酮。该高区域选择性的串联过程基于分子间的乌尔曼型 C-芳基化反应，随后是分子内的乌尔曼型 O-芳基化反应。通过使用取代的 1-溴-2-碘苯和取代的 1,3-环己二酮作为底物，可以得到取代的产物。与非环状 1,3-二酮反应生成相应的苯并[b]呋喃。
