ORGN 337 |
| Dirhodium(II) complexes perform exceptionaliy well as metal carbene catalysts in reactions with diazocarbonyl compounds (cyclopropanation, C-H insertion, ylide formation, among others), as Lewis acids in reactions such as hetero-Diels-Alder, and as oxidation catalysts in reactions with common chemical oxidants that include tert-butyl hydroperoxide (allylic and benzylic oxidations, oxidative Mannich reactions, for example). Although dirhodium(II) carboxylates are generally more reactive than the corresponding carboxamidates, the carboxamidates are better suited to the functioning of chiral ligands for asymmetric induction in metal carbene reactions with diazoacetates and as Lewis acids. And the very low oxidation potential of the dirhodium(II) carboxamidates, relative to the carboxylates, makes them much more suitable as oxidation catalysts. The linkage of two rhodiums in their classic structural motif enhances their stability, thereby increasing turn-over numbers of reactions that they catalyze. |
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Arthur C. Cope Award and Arthur C. Cope Scholar Awards
8:00 AM-12:10 PM, Tuesday, 12 September 2006 Moscone Center -- Room 134, Oral
Division of Organic Chemistry |