Catalytic enantioselective synthesis of alpha-aminooxy and alpha-hydroxy ketone using nitrosobenzene.
The highly enantioselective and O-selective nitroso aldol reaction of tin enolates 2 and nitrosobenzene (1) has been developed with the use of (R)-BINAP-silver complexes as a catalyst. After the various silver salts were surveyed, the AgOTf and the AgClO4 complex were found to be optimal in the O-selective nitroso aldol reaction in both asymmetric induction (up to 97% ee) and regioselection (O/N = >99/1), affording aminooxy ketone 3. The product 3 can be transformed to alpha-hydroxy ketone 5 without any loss of enantioselectivity. Thus, the method provides an efficient approach to the catalytic enantioselective introduction of oxygen alpha- to the carbonyl group.
Momiyama
Norie
N
Department of Chemistry, University of Chicago, 5735 South Ellis Avenue, Illinois 60637, USA.
Yamamoto
Hisashi
H
D000438:Alcohols / Q000138:chemical synthesis*; D002384:Catalysis; D003512:Cyclohexanones / Q000138:chemical synthesis; D006898:Hydroxylamines / Q000138:chemical synthesis*; D007659:Ketones / Q000138:chemical synthesis*; D009603:Nitroso Compounds / Q000737:chemistry*; D013237:Stereoisomerism
D000438:Alcohols; D003512:Cyclohexanones; D006898:Hydroxylamines; D007659:Ketones; D009603:Nitroso Compounds; C012456:nitrosobenzene