Enantioselective Ir-catalyzed allylic aminations with hydroxamic acid derivatives are described. Catalysts were prepared in situ from [Ir(cod)Cl](2) or [Ir(dbcot)Cl](2), a phosphoramidite and base. In addition, pure (π-allyl)Ir complexes containing cod or dbcot as auxiliary ligands were used. Very high degrees of regio- and enantioselectivity were achieved. The reaction products were transformed into piperidine derivatives suited as precursors for aza-sugars.
Enantioselective Iridium-Catalyzed Allylic Substitutions with Hydroxamic Acid Derivatives as N-Nucleophiles. -Different protocols are developed for the regioand enantioselective allylic aminations of various hydroxamic acid derivatives. The proper choice of base and in situ generation of the Ir complexes is essential. Further transformations of the products such as ester (V), obtained from (S)-(IV) [= ent-(IIIa)] or diene (VIII) leading to synthetically valuable heterocycles are demonstrated. -(GAERTNER, M.; JAEKEL, M.; ACHATZ, M.; SONNENSCHEIN, C.; TVERSKOY, O.; HELMCHEN*, G.; Org. Lett. 13 (2011) 11, 2810-2813, http://dx.
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