Abstract
ZnBr2-catalyzed stereoselective [5 + 2] annulation of N-acryloyl indoles with cyclic sulfonyl enamides is reported, providing a concise and efficient synthesis of isoeburnamonine, which is the key intermediate for norvincamine. Both [2 + 2] and [4 + 2] cycloadducts, depending on the ring size of the enamides, have been shown to be the important intermediates for this [5 + 2] annulation.
| Original language | English |
|---|---|
| Pages (from-to) | 1013-1017 |
| Number of pages | 5 |
| Journal | Organic Letters |
| Volume | 22 |
| Issue number | 3 |
| DOIs | |
| State | Published - 7 Feb 2020 |