Copper- or Phosphine-Catalyzed Reaction of Alkynes with Isocyanides. Regioselective Synthesis of Substituted Pyrroles Controlled by the Catalyst
摘要:
The copper-catalyzed reaction of isocyanides (CNCH(2)EWG(1)) 1 with electron-deficient alkynes (RC equivalent to CEWG(2)) 2 gave the 2,4-di-EWG-substituted pyrroles 3 selectively, whereas the phosphine-catalyzed reaction of 1 with 2 afforded the 2,3-di-EWG-subsituted pyrroles 4. Accordingly, regioselective synthesis of substituted pyrroles has been achieved by merely choosing the catalyst.
The copper-catalyzed reaction of isocyanides (CNCH(2)EWG(1)) 1 with electron-deficient alkynes (RC equivalent to CEWG(2)) 2 gave the 2,4-di-EWG-substituted pyrroles 3 selectively, whereas the phosphine-catalyzed reaction of 1 with 2 afforded the 2,3-di-EWG-subsituted pyrroles 4. Accordingly, regioselective synthesis of substituted pyrroles has been achieved by merely choosing the catalyst.