Dimeric quinidine-catalyzed enantioselective aminooxygenation of oxindoles: an organocatalytic approach to 3-hydroxyoxindole derivatives.
3-Hydroxyoxindoles are common structural motifs found in a vast array of natural and biologically active molecules. Most catalytic methods for the asymmetric syntheses of these compounds require the use of transition-metal catalysts. In contrast, alternative catalytic procedures involving organocatalysis are scarce. Herein we disclose a novel aminooxygenation of oxindoles with nitrosobenzene catalyzed by a newly designed quinidine dimer to afford the desired products in good yields with enantioselectivities up to 96%. These reactions allow one to construct a C-O bond at the C(3) position of oxindoles with the creation of an oxygen-containing tetrasubstituted chiral center and provide a new, general organocatalytic approach to the synthesis of 3-hydroxyoxindole derivatives.
Bui
Tommy
T
The Skaggs Institute for Chemical Biology and Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
Candeias
Nuno R
NR
Barbas
Carlos F
CF
D002384:Catalysis; D019281:Dimerization; D007211:Indoles / Q000737:chemistry*; D009603:Nitroso Compounds / Q000737:chemistry; D010084:Oxidation-Reduction; D000078183:Oxindoles; D011802:Quinidine / Q000737:chemistry*; D013237:Stereoisomerism; D013379:Substrate Specificity
D007211:Indoles; D009603:Nitroso Compounds; D000078183:Oxindoles; C022960:2-oxindole; D011802:Quinidine; C012456:nitrosobenzene