ORGN 129 |
| Much effort in indium-mediated reactions has been focused on synthetic applications recently because indium metal is stable in air and easy to handle, and the toxicity observed for many metals is little known for indium. As indium-mediated reactions are applicable to the reductive heterocyclizations, we examined indium-mediated reactions for the reductive cyclizations of 2-nitro-substituted ethylnylarenes to indoles. Indoles have been known as the basis of pharmacologically and biologically active molecules. One-pot reductive cyclizations of 2-nitroethylnylarenes to indoles could be successful if reductive reaction between the nitro group and indium effectively triggers cyclizations to the triple bond. Attempted heterocyclizations of 2-nitroethynylarenes in the presence of indium/indium(III) chloride was not successful; i.e., 2-ethynylanilines were obtained as a major product instead of indole formation. However, one-pot synthesis of indoles was suitably worked in good yield in the presence of indium and hydroiodic acid. Herein, we report the development of one-pot indole synthesis via indium-mediated reductive heterocyclization reactions. |
|
Process R&D, Physical Organic Chemistry, Heterocycles, Aromatics, Metal-Mediated Reactions
8:00 PM-10:00 PM, Sunday, March 25, 2007 Hyatt Regency Chicago -- Riverside Center, Poster
Division of Organic Chemistry |