Here we summarise our results for SmI2-induced 5-exo-trig to 8-exo-trig reductive cyclisations of suitably substituted indole and pyrrole derivatives. All precursors were easily prepared by simple N-alkylation or N-acylation of indole and pyrrole derivatives with the corresponding iodo alkanones, acid chlorides or lactones. The SmI2-induced cyclisations in most cases provided tri- and tetracyclic derivatives
Efficient Synthesis of Medium-Sized Rings Incorporating Indole or Pyrrole Units by Samarium Diiodide Induced Cyclizations
作者:Virginie Blot、Hans-Ulrich Reißig
DOI:10.1002/ejoc.200600743
日期:2006.11
Samariumdiiodide promoted the intramolecular reductive couplings of N-alkylated indole and pyrrole derivatives 9–12 and 14 to afford products 15–19 that incorporate seven- and eight-membered rings. They were obtained in good yields and generally with excellent diastereoselectivities. Up to four contiguous stereogenic centres are controlled in this transformation, which is explained by a highly ordered