ORGN 446 |
| Synthesis of 3-benzazepinones by palladium-catalyzed intramolecular addition of amides to alkynes is achieved. The desired seven-membered ring formation was accomplished from 2-alkynyl phenylacetamide in the presence of 5% Pd(OAc)2(PPh3)2 and bases such as KOH or NaOEt. It was found that regioselective 4-alkyl-3-benzazepinone synthesis could be obtained in good yields from 2-alkylethynyl phenylacetamide. A five-membered ring 3-indenecarboxamide was identified as the major by-product, the formation of which was promoted by strong basic and thermal conditions. On the other hand, in the case of 2-arylethynyl and 2-alkenylethynyl phenylacetamide, 3-isoquinolinone derivatives were observed as six-membered ring formation product. The synthesis, methodology along with a mechanistic rationale will be presented. |
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Modern Acetylene Chemistry
8:00 PM-10:00 PM, Tuesday, 12 September 2006 Moscone Center -- Hall D, Poster
Sci-Mix
Division of Organic Chemistry |