ORGN 886 |
| Au salts can efficiently activate alkynes and allenes toward attacks of various nucleophiles intra-/intermolecularly. Combining the reactivity of Au catalysts toward both types of substrates in tandem processes can provide exceptionally efficient access to a range of functional structures. Herein, we report Au-catalyzed reactions of propargylic esters via a general theme of 3,3-rearrangement upon alkyne activation followed by the activation of the in situ generated carboxylic allenes. A highly reactive oxocarbenium intermediate with multiple functional groups and diverse reactivities is generated. We have been able to engage this intermediate into a variety of reactions, leading to various synthetically versatile structures including E-enones, highly functionalized cyclobutanes/cyclopentenes, 2-cyclopenteones, dienyl esters, and alkylidene diketones. Based on this strategy, remarkably efficient methods of synthesizing functional molecules are developed from readily available propargylic esters. |
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New Reactions and Methodology
8:00 AM-11:40 AM, Thursday, 14 September 2006 Moscone Center -- Room 133, Oral
Division of Organic Chemistry |