ORGN 273 |
| The unique applications of spiro bis(isoxazoline) ligands (SPRIX) were elucidated to be due to a combined effect of their moderate coordinating ability toward Pd and the rigid spiro backbone. In continuation to our study novel hybrid ligands containing an unsymmetrical spiro backbone, isoxazoline and isoxazole as the two coordinating units were developed. These ligands had a very good affinity for Pd(II) and their Pd complex promoted the tandem cyclization of dialkenyl alcohols quite rapidly at 0 oC, furnishing the tandem cyclized product in up to 97% ee. In addition, application of Pd-SPRIX complex was demonstrated in the asymmetric aminocarbonylation of alkenyl urea substrates producing the cyclic product in up to 88% ee. Further extension of the Pd-SPRIX complex was explored in enantioselective co-polymerization of styrene and CO to produce a polyketone with high molecular weight and optical activity. All these applications of spiro ligands will be discussed in detail.
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Metal-Mediated Reactions and Syntheses
8:00 AM-12:00 PM, Monday, 11 September 2006 Moscone Center -- Room 133, Oral
Division of Organic Chemistry |
