ORGN 118 |
| The Suzuki reaction is a powerful tool of making C-C bonds, particularly between two aryl groups. In an effort directed at preparing tri-aryl substituted pyrroles employing sequential, one-pot Suzuki reactions on polyhalopyrroles, we found that one halide can be selectively coupled in the presence of other halides. This selectivity is the result of the inherent reactivity difference between carbon-halide bonds. The sites and order of the couplings can be predicted based on the 1H and 13C NMR of the parent non-halogenated substrates. Selectivities have been obtained on 3,4-, 3,5- and 4,5-dibromo substrates. Interestingly, in the case of the 3,5-dibromo substrate, the regioselecitivity can be reversed depending upon the polarity of the solvents used. Our study also showed more than one coupling can be done in one reaction pot. The conditions developed for these regioselective Suzuki reactions and the effects of solvent will be presented.
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Heterocycles, Aromatics, Materials, Devices, Switches, Combinatorial Chemistry, Metal-Mediated Reactions
8:00 PM-10:00 PM, Sunday, 13 March 2005 Convention Center -- Hall D, Poster
Division of Organic Chemistry |
