ORGN 100 |
Hydrogenation of 2,3-diphenylbutadiene: A revealing kinetic study
| Xiuhua Cui, Department of Chemistry, Texas A&M University, College Station, TX 77843 and Kevin Burgess, Department of Chemistry, Texas A&M University, PO Box 30012, College Station, TX 77842-3012. |
There have been surprisingly few reports on asymmetric hydrogenation of dienes and polyenes, and none where the conjugated system has no functional groups attached. We have studied asymmetric hydrogenation of 2,3-butadiene as the first step in a long term effort to elucidate and optimize the enantio-and diastereoselectivities of such reactions. Kinetic data for this hydrogenation mediated by the iridium complex 1 indicates the reaction predominantly occurs in two steps: hydrogenation to enantiomeric butene derivatives, then reduction of the remaining double bond. Only a small amount of the completely reduced products are obtained before all the diene substrate is consumed. Further, the enantioface selectivity of the reaction appears to change in the first and second reduction steps. This mechanism will be discussed in detail and compared to relevant theoretical calculations by others. |
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New Reactions and Methodology, Metal-Mediated Reactions, Heterocycles and Aromatics
8:00 PM-10:00 PM, Sunday, March 28, 2004 Anaheim Convention Center -- Hall A, Poster
Division of Organic Chemistry
The 227th ACS National Meeting, Anaheim, CA, March 28-April 1, 2004
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