CHED 528 |
| Rhodium carbenoids are powerful reactive intermediates capable of C-H insertion and cyclopropanation. In such reactions, diastereoselectivity can be controlled by choice of carbenoid precursor and enantioselectivity can be controlled by choice from among a wide variety of single enantiomer catalysts. While cyclopropanation of alkenes such as styrene can be highly diastereoselective, we have found poor diastereoselectivity in cyclopropanation of phenyl-1,2-propadiene, consistent with the phenyl ring being removed from proximity to the diastereogenic group on the carbenoid. Diastereoselectivity is not an issue in the corresponding 1,1-diphenyl alkylidine cyclopropanes. We will discuss our investigation of diastereoselective allene cyclopropanations using achiral rhodium catalysts as well as the chiral induction possible with rhodium tetraprolinate catalysts.
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Undergraduate Research Poster Session: Organic Chemistry
11:00 AM-1:00 PM, Monday, March 26, 2007 Hyatt Regency Chicago -- Riverside Center, Poster
Division of Chemical Education |
