ORGN 369 |
| Carbolithiation of the N-substituted ortho-amino stilbenes (1-E) proceeds with complete regioselectivity to generate the lithiated intermediate (2). Subsequent reaction with the electrophile DMF initiates a cascade process which can be utilized to selectively produce tetrahydro-quinoline, dihydro-quinoline or quinoline derivatives depending upon substituents and reaction conditions. In contrast, a switch in chemoselectivity is observed for the (1-Z) analogues, which undergo a regioselective alkene deprotonation to generate the vinyl lithiated intermediates (3). Following treatment with DMF the 3-benzylidene-indole-2-ols (4) are isolated and can be subsequently converted into the C-3 functionalised indoles by reaction with a range of nucleophiles. The scope and selectivity of both reaction sequences will be outlined in terms of reaction conditions, tolerance of substrate substituents and diversity of products obtainable from the methodologies.
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New Reactions and Methodology
8:00 AM-12:00 PM, Tuesday, 12 September 2006 Moscone Center -- Room 133, Oral
Division of Organic Chemistry |
