We report a flexible approach to the total synthesis of 4,5-dioxoaporphines based on the palladium(0) catalyzed Suzuki cross-coupling of phenylboronic acids with sterically hindered 2-bromo phenyl acetates or bromo phenyl acetamides, followed by sequential bicyclization of biarylacetamides promoted by oxalyl chloride/Lewis acid. The reduction of 4,5-dioxoaporphines provides a chemoselective entry to aporphines, dehydroaporphines and 4-hydroxy- dehydroaporphines. A three-steps total synthesis for (±)-O,O′- dimethylapomorphine from readily accessible precursors is also reported. © 2004 Elsevier Ltd. All rights reserved.
|Publication status||Published - 28 Jun 2004|
- Cascade cyclization
- Oxalyl chloride
- Suzuki cross-coupling