| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1346091 | Tetrahedron: Asymmetry | 2012 | 9 Pages |
An efficient diastereo- and enantioselective Michael addition of 3-substituted oxindoles onto nitroalkenes catalyzed by a bifunctional chiral squaramide catalyst has been developed. This organocatalytic reaction with 2 mol % of catalyst proceeded smoothly to afford 3,3-disubstituted oxindoles in high yields with good diastereoselectivities and enantioselectivities (up to 98:2 dr, 88% ee).
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(3S)-tert-Butyl 3-methyl-3-[(1R)-2-nitro-1-phenylethyl]-2-oxoindoline-1-carboxylateC22H24N2O5Ee = 86%[α]D28=+27.6 (c 1.63, CH2Cl2)Source of chirality: asymmetric synthesisAbsolute configuration: (S,R)
(3S)-tert-Butyl 3-[(1R)-1-(4-methoxyphenyl)-2-nitroethyl]-3-methyl-2-oxoindoline-1-carboxylateC23H26N2O6Ee = 87%[α]D20=+6.3 (c 1.08, CH2Cl2))Source of chirality: asymmetric synthesisAbsolute configuration: (S,R)
(3S)-tert-Butyl 3-[(1R)-1-(3,4-dimethoxyphenyl)-2-nitroethyl]-3-methyl-2-oxoindoline-1-carboxylateC24H28N2O7Ee = 79%[α]D22=+1.7 (c 2.46, CH2Cl2)Source of chirality: asymmetric synthesisAbsolute configuration: (S,R)
(3S)-tert-Butyl 3-[(1R)-1-(4-methylphenyl)-2-nitroethyl]-3-methyl-2-oxoindoline-1-carboxylateC23H26N2O5Ee = 88%[α]D22=+13.0 (c 0.97, CH2Cl2)Source of chirality: asymmetric synthesisAbsolute configuration: (S,R)
(3S)-tert-Butyl 3-[(1R)-1-(4-fluorophenyl)-2-nitroethyl]-3-methyl-2-oxoindoline-1-carboxylateC22H23FN2O5Ee = 64%[α]D22=+11.8 (c 0.97, CH2Cl2)Source of chirality: asymmetric synthesisAbsolute configuration: (S,R)
(3S)-tert-Butyl 3-[(1R)-1-(4-chlorophenyl)-2-nitroethyl]-3-methyl-2-oxoindoline-1-carboxylateC22H23ClN2O5Ee = 80%[α]D20=+7.5 (c 1.31, CH2Cl2)Source of chirality: asymmetric synthesisAbsolute configuration: (S,R)
(3S)-tert-Butyl 3-[(1R)-1-(2-chlorophenyl)-2-nitroethyl]-3-methyl-2-oxoindoline-1-carboxylateC22H23ClN2O5Ee = 85%[α]D20=+40.8 (c 0.74, CH2Cl2)Source of chirality: asymmetric synthesisAbsolute configuration: (S,R)
(3S)-tert-Butyl 3-[(1R)-1-(4-bromophenyl)-2-nitroethyl]-3-methyl-2-oxoindoline-1-carboxylateC22H23BrN2O5Ee = 81%[α]D20=+4.2 (c 1.57, CH2Cl2)Source of chirality: asymmetric synthesisAbsolute configuration: (S,R)
(3S)-tert-Butyl 3-[(1R)-1-(2-furanyl)-2-nitroethyl]-3-methyl-2-oxoindoline-1-carboxylateC20H22N2O6Ee = 76%[α]D20=+48.3 (c 1.27, CH2Cl2)Source of chirality: asymmetric synthesisAbsolute configuration: (S,R)
(3S)-tert-Butyl 3-methyl-3-[(1R)-2-nitro-1-(2-thienyl)ethyl]-2-oxoindoline-1-carboxylateC20H22N2O5SEe = 70%[α]D20=+18.0 (c 1.28, CH2Cl2)Source of chirality: asymmetric synthesisAbsolute configuration: (S,R)
(3S)-tert-Butyl 3-methyl-3-[(1R)-1-nitromethyl-3-phenylpropyl]-2-oxoindoline-1-carboxylateC24H28N2O5Ee = 76%[α]D20=+27.2 (c 1.30, CH2Cl2)Source of chirality: asymmetric synthesisAbsolute configuration: (S,R)
(3S)-tert-Butyl 3-ethyl-3-[(1R)-2-nitro-1-phenylethyl]-2-oxoindoline-1-carboxylateC23H26N2O5Ee = 87%[α]D20=+15.5 (c 1.92, CH2Cl2)Source of chirality: asymmetric synthesisAbsolute configuration: (S,R)
(3S)-tert-Butyl 3-benzyl-3-[(1R)-2-nitro-1-phenylethyl]-2-oxoindoline-1-carboxylateC28H28N2O5Ee = 86%[α]D20=+3.0 (c 1.22, CH2Cl2)Source of chirality: asymmetric synthesisAbsolute configuration: (S,R)
(3R)-tert-Butyl 3-phenyl-3-[(1R)-2-nitro-1-phenylethyl]-2-oxoindoline-1-carboxylateC27H26N2O5Ee = 44%[α]D20=+64.3 (c 2.11, CH2Cl2)Source of chirality: asymmetric synthesisAbsolute configuration: (R,R)
(3S)-3-Methyl 3-[(1R)-2-nitro-1-phenylethyl]-2H-indol-2-oneC17H16N2O3Ee = 85%[α]D25=-27.8 (c 0.80, CH2Cl2)Source of chirality: asymmetric synthesisAbsolute configuration: (S,R)
(3S)-tert-Butyl 5-methoxy-3-methyl--3-[(1R)-2-nitro-1-phenylethyl]-2-oxoindoline-1-carboxylateC23H26N2O6Ee = 84%[α]D28=-5.1 (c 1.50, CH2Cl2)Source of chirality: asymmetric synthesisAbsolute configuration: (S,R)
(3S)-tert-Butyl 5-fluoro-3-methyl-3-[(R)-2-nitro-1-phenylethyl]-2-oxoindoline-1-carboxylateC22H23FN2O5Ee = 79%[α]D28=+28.6 (c 1.52, CH2Cl2)Source of chirality: asymmetric synthesisAbsolute configuration: (S,R)
(3S)-tert-Butyl 3-methyl-3-[(1R)-1-nitromethylpropyl]-2-oxoindoline-1-carboxylateC18H24N2O5Ee = 88%[α]D28=+43.5 (c 1.13, CH2Cl2)Source of chirality: asymmetric synthesisAbsolute configuration: (S,R)
(3S)-3-Methyl-3-[(1R)-2-nitro-1-phenylethyl]-1-phenyl-indolin-2-oneC23H20N2O3Ee = 54%[α]D28=+5.8 (c 2.11, CH2Cl2)Source of chirality: asymmetric synthesisAbsolute configuration: (S,R)
(3S)-Ethyl 3-methyl-3-[(1R)-2-nitro-1-phenylethyl]-2-oxoindoline-1-carboxylateC20H20N2O5Ee = 91%[α]D28=+18.4 (c 3.06, CH2Cl2)Source of chirality: asymmetric synthesisAbsolute configuration: (S,R)
3,4-Bis[[(1S,2S)-2-(1-piperidinyl)cyclohexyl]amino]-3-cyclobutene-1,2-dioneC26H42N4O2Ee = >99%[α]D25=+48.4 (c 0.19, CH2Cl2-DMSO 1:1 v/v)Source of chirality: (1S,2S)-1,2-diaminocyclohexaneAbsolute configuration: (S,S,S,S)
