The 2′-phenyl cinchonidine thiourea-catalyzed asymmetric addition of alcohols to isatin-derived N-Boc ketimines

Optically active isatin-derived N,O-aminals were obtained through the catalytic asymmetric addition of various alcohols to isatin-derived N-Boc ketimines. Using 2′-phenyl cinchonidine thiourea as the catalyst, adducts were obtained in 96% yield and with up to 92% ee.

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(R)-tert-Butyl (3-(benzyloxy)-1-methyl-2-oxoindolin-3-yl)carbamateC21H24N2O4[α]D20 = +22 (c 1.0, CHCl3)Source of chirality: OrganocatalysisAbsolute configuration: (R)

(R)-tert-Butyl (3-(benzyloxy)-1-ethyl-2-oxoindolin-3-yl)carbamateC22H26N2O5[α]D20 = +10 (c 1.0, CHCl3)Source of chirality: OrganocatalysisAbsolute configuration: (R)

(R)-tert-Butyl (3-(benzyloxy)-1-(methoxymethyl)-2-oxoindolin-3-yl)carbamateC22H26N2O5[α]D20 = +11 (c 1.0, CHCl3)Source of chirality: OrganocatalysisAbsolute configuration: (R)

(R)-tert-Butyl (1-allyl-3-(benzyloxy)-2-oxoindolin-3-yl)carbamateC23H26N2O4[α]D20 = +9 (c 1.0, CHCl3)Absolute configuration: (R)Source of chirality: Organocatalysis

(R)-tert-Butyl (1-benzyl-3-(benzyloxy)-2-oxoindolin-3-yl)carbamateC27H28N2O4[α]D20 = +18 (c 1.0, CHCl3)Absolute configuration: (R)Source of chirality: Organocatalysis

(R)-tert-Butyl (3-(benzyloxy)-1-methyl-5-nitro-2-oxoindolin-3-yl)carbamateC21H23N3NaO6[α]D20 = +38 (c 1.0, CHCl3)Absolute configuration: (R)Source of chirality: Organocatalysis

(R)-tert-Butyl (3-(benzyloxy)-5-fluoro-1-methyl-2-oxoindolin-3-yl)carbamateC21H23FN2O4[α]D20 = +23 (c 1.0, CHCl3)Absolute configuration: (R)Source of chirality: Organocatalysis

(R)-tert-Butyl (3-(benzyloxy)-5-chloro-1-methyl-2-oxoin-dolin-3-yl)carbamateC21H23ClN2O4[α]D20 = +22 (c 1.0, CHCl3)Absolute configuration: (R)Source of chirality: Organocatalysis

(R)-tert-Butyl (3-(benzyloxy)-5-bromo-1-methyl-2-oxoi-ndolin-3-yl)carbamateC21H23BrN2O4[α]D20 = +25 (c 1.0, CHCl3)Absolute configuration: (R)Source of chirality: Organocatalysis

(R)-tert-Butyl (3-(benzyloxy)-1,5-dimethyl-2-oxoindolin-3-yl)carbamateC22H26N2O44[α]D20 = +19 (c 1.0, CHCl3)Absolute configuration: (R)Source of chirality: Organocatalysis

(R)-tert-Butyl(3-(benzyloxy)-5-methoxy-1-methyl-2-oxoindolin-3-yl)carbamateC22H26N2O5[α]D20 = +22 (c 1.0, CHCl3)Absolute configuration: (R)Source of chirality: Organocatalysis

(R)-tert-Butyl (3-(benzyloxy)-6-bromo-1-methyl-2-oxoi-ndolin-3-yl)carbamateC21H23BrN2O44[α]D20 = +20 (c 1.0, CHCl3)Absolute configuration: (R)Source of chirality: Organocatalysis

(R)-tert-Butyl (3-(benzyloxy)-7-bromo-1-methyl-2-oxoindolin-3-yl)carbamateC21H23BrN2O4[α]D20 = +9 (c 1.0, CHCl3)Absolute configuration: (R)Source of chirality: Organocatalysis

(R)-tert-Butyl (3-(benzyloxy)-7-chloro-1-methyl-2-oxoindolin-3-yl)carbamateC21H23ClN2O4[α]D20 = +11 (c 1.0, CHCl3)Absolute configuration: (R)Source of chirality: Organocatalysis

(R)-tert-Butyl (3-(benzyloxy)-5,7-dibromo-1-methyl-2-oxoindolin-3-yl)carbamateC21H22Br2N2O4[α]D20 = +54 (c 1.0, CHCl3)Absolute configuration: (R)Source of chirality: Organocatalysis

(R)-tert-Butyl (3-methoxy-1-methyl-2-oxoindolin-3-yl)carbamateC15H20N2O4[α]D20 = +33 (c 1.0, CHCl3)Absolute configuration: (R)Source of chirality: Organocatalysis

(R)-tert-Butyl (3-ethoxy-1-methyl-2-oxoindolin-3-yl)carbamateC16H22N2O4[α]D20 = +26 (c 1.0, CHCl3)Absolute configuration: (R)Source of chirality: Organocatalysis

(R)-tert-Butyl (3-(allyloxy)-1-methyl-2-oxoindolin-3-yl)carbamateC17H22N2O4[α]D20 = +19 (c 1.0, CHCl3)Absolute configuration: (R)Source of chirality: Organocatalysis

(R)-tert-Butyl (1-methyl-2-oxo-3-(prop-2-yn-1-yloxy)in-dolin-3-yl)carbamateC17H20N2O4[α]D20 = +16 (c 1.0, CHCl3)Absolute configuration: (R)Source of chirality: Organocatalysis

(R)-tert-Butyl (1-methyl-2-oxo-3-propoxyindolin-3-yl)carbamateC17H24N2O4[α]D20 = +20 (c 1.0, CHCl3)Absolute configuration: (R)Source of chirality: Organocatalysis

(R)-tert-Butyl (3-butoxy-1-methyl-2-oxoindolin-3-yl)carbamateC18H26N2O4[α]D20 = +19 (c 1.0, CHCl3)Absolute configuration: (R)Source of chirality: Organocatalysis

(R)-tert-Butyl (3-isopropoxy-1-methyl-2-oxoindolin-3-yl)carbamateC17H24N2O4[α]D20 = +11 (c 1.0, CHCl3)Absolute configuration: (R)Source of chirality: Organocatalysis

(R)-tert-Butyl(1-methyl-2-oxo-3-((4-(trifluoromethyl)benzyl)oxy)indolin-3-yl)carbamateC22H23F3N2O4[α]D20 = +23 (c 1.0, CHCl3)Absolute configuration: (R)Source of chirality: Organocatalysis

(R)-tert-Butyl (1-methyl-3-((4-nitrobenzyl)oxy)-2-oxoi-ndolin-3-yl)carbamateC21H23N3O6[α]D20 = +29 (c 1.0, CHCl3)Absolute configuration: (R)Source of chirality: Organocatalysis

(R,E)-tert-Butyl (3-(cinnamyloxy)-1-methyl-2-oxoindolin-3-yl)carbamateC23H26N2O4[α]D20 = +45 (c 1.0, CHCl3)Absolute configuration: (R)Source of chirality: Organocatalysis

(R)-tert-Butyl (3-(but-3-en-1-yloxy)-1-methyl-2-oxoind-olin-3-yl)carbamateC18H24N2O4[α]D20 = +20 (c 1.0, CHCl3)Absolute configuration: (R)Source of chirality: Organocatalysis

(R,E)-tert-Butyl (3-(but-2-en-1-yloxy)-1-methyl-2-oxoindolin-3-yl)carbamateC18H24N2O4[α]D20 = +29 (c 1.0, CHCl3)Absolute configuration: (R)Source of chirality: Organocatalysis

(R)-tert-Butyl (3-(tert-butylperoxy)-1-methyl-2-oxoindolin-3-yl)carbamateC18H26N2O5[α]D20 = +3 (c 1.0, CHCl3)Absolute configuration: (R)Source of chirality: Organocatalysis