ORGN 524 |
| The Claisen rearrangement of allyl vinyl ethers was discovered nearly one hundred years ago and provides a powerful method for the formation of carbon-carbon bonds with control of stereochemistry through an ordered transition state. However, difficulty in synthesizing the substrates severely limits the versatility of this method. In order to circumvent this limitation, a number of variations of the Claisen rearrangement have been developed, such as the Ireland-Claisen, Eschenmoser-Claisen, and Johnson-Claisen rearrangements. There remains a need for a mild, versatile, and stereospecific route to allyl vinyl ether substrates that is compatible with acid and base sensitive and redox sensitive groups, is easy to perform, uses cheap and non-toxic reagents, has wide substrate structural variability, and occurs with well defined stereochemistry. Such a method may significantly expand the power of the Claisen rearrangement and progress toward a generalized solution will be presented. A copper-promoted coupling of vinyl pinacol boronate esters with allyl alcohol yielding allyl vinyl ethers that is stereospecific and tolerant of a wide array of functional groups will be detailed.
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Physical Organic Chemistry, Metal-Mediated Reactions, Asymmetric Reactions and Syntheses
8:00 PM-10:00 PM, Tuesday, August 21, 2007 BCEC -- Exhibit Hall - B2, Poster
Division of Organic Chemistry |
