ORGN 450 |
| Cationic Au(I) complexes have found increasing use as catalysts, especially in systems exploiting their propensity to activate alkynes towards nucleophilic addition. Recently, we and others have speculated that these complexes might stabilize cationic reaction intermediates via back-bonding from gold into a conjugated electron-deficient system. Formally, such an interaction can be represented by a resonance structure illustrating a gold carbene. In order to probe for intermediates of this form, an intramolecular acetylenic Schmidt reaction was developed, whereby homopropargyl azides are cyclized to form regiospecifically substituted pyrroles. Additionally, attempts to trap carbenoid intermediates derived from propargyl acetates led to the development of an intramolecular Rautenstrauch reaction and an intermolecular cyclopropanation reaction. The cyclopropanation chemistry has been rendered enantioselective through the use of chiral phosphine ligands. |
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Modern Acetylene Chemistry
8:00 PM-10:00 PM, Tuesday, 12 September 2006 Moscone Center -- Hall D, Poster
Sci-Mix
Division of Organic Chemistry |