Zinc-catalyzed asymmetric nitrooxylation of β-keto esters/amides with a benziodoxole-derived nitrooxy transfer reagent†
Abstract
The first asymmetric nitrooxylation of cyclic β-keto esters/amides with an easily accessible hypervalent iodine-based nitrooxylating reagent is reported. The reaction was catalyzed using the combination of Zn(ClO4)2·6H2O and a dbfox ligand under mild reaction conditions and could also be scaled up to gram quantities, providing a series of α-nitrooxy β-keto esters/amides in high yields (84%–99%) and with low to moderate enantioselectivities (up to 78% ee).