ORGN 372 |
| D. W. Slocum, S. Brown, S. Dumbris, E. Mullins, D. Woosley, A. Spencer, S. Eilerman, and R.W. Holman. Department of Chemistry, Western Kentucky University, 1 Big Red Way, Bowling Green, KY 42101 |
| Improvement of the efficiency of homogeneous processes is a never-ending quest. Stability, activity, selectivity, solubility and mechanism of operation must be continuously scrutinized. With regard to the directed ortho-metalation reaction, the stabilities of the most common catalyst, TMEDA, and the most common solvent, ethers, have been amply studied. Yet little is known of the contribution of these components to metalation efficiency save a vague knowledge of their ability to deoligomerize n-BuLi. By NMR examination of the contributions of increments of these agents to n-BuLi's reactivity in hydrocarbon solvents, a picture of their mode of operation is gradually emerging (accompanying poster). Notably, significant insight into the deoligomerization efficiencies of THF, MTBE and TMEDA in hydrocarbon solvents has been assessed using 7Li NMR spectroscopy. Also, the basicities of these systems have been assessed by rate/extent of benzyne formation studies. Emerging is a snapshot of the coordination efficiencies of these systems with DMG's of various arenes resulting in the hypothesis that such coordination, visible by 13C NMR, can be correlated with the rate of ortho-metalation. Lastly, observation of the coordination lifetimes of the various n-BuLi/ether or amine systems affords further insight into the activity of these systems. |
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Physical Organic, Materials, Heterocycles, Aromatics, Metal-Mediated Reactions
8:00 PM-10:00 PM, Tuesday, September 9, 2003 Hilton New York -- Americas Hall 1, Poster
Sci-Mix
Division of Organic Chemistry |