| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1345602 | Tetrahedron: Asymmetry | 2016 | 9 Pages |
We have developed C-6′-modified quinine quaternary ammonium salts as phase transfer catalysts for α-hydroxylation of β-dicarbonyl compounds. The quinine quaternary ammonium salts, which was modified at C-6′ and the N atom, had good activity for α-hydroxylation of β-dicarbonyl compounds. By using 5 mol % of 6-hydroxyl-N-(4′-fluoro-2′-trifluoromethyl)quinine quaternary ammonium salt as the organocatalyst, cumene hydroperoxide as the oxidant, toluene as the solvent, and 50% K2HPO4 as the aqueous alkali at room temperature, the yield and enantioselectivity of the α-hydroxylation of β-keto esters were 95% and 88%, respectively. This catalytic system was also applicable for β-keto amides (92% yield and 76% ee).
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(1S,3R,5S)-Adamantan-1-yl (2R)-2-hydroxy-1-oxo-2,3-dihydro-1H-indene-2-carboxylateC20H22O4[α]D15 = −56.9 (c 0.29, MeOH)Source of chirality: asymmetric catalysisAbsolute configuration: (1S,3R,5S) (2R)
(1S,3R,5S)-Adamantan-1-yl (2R)-6-fluoro-2-hydroxy-1-oxo-2,3-dihydro-1H-indene-2-carboxylateC20H21FO4[α]D15 = −35.7 (c 0.17, MeOH)Source of chirality: asymmetric catalysisAbsolute configuration: (1S,3R,5S) (2R)
(1S,3R,5S)-Adamantan-1-yl (2R)-5-chloro-2-hydroxy-1-oxo-2,3-dihydro-1H-indene-2-carboxylateC20H21ClO4[α]D15 = −20.3 (c 0.23, MeOH)Source of chirality: asymmetric catalysisAbsolute configuration: (1S,3R,5S) (2R)
(3R,5R,7R)-Adamantan-1-yl (2R)-4-bromo-2-hydroxy-1-oxo-2,3-dihydro-1H-indene-2-carboxylateC20H21BrO4[α]D15 = −8.9 (c 0.35, MeOH)Source of chirality: asymmetric catalysisAbsolute configuration: (1R,3R,5R) (2R)
(3R,5R,7R)-Adamantan-1-yl (2R)-2-hydroxy-6-methoxy-1-oxo-2,3-dihydro-1H-indene-2-carboxylateC21H24O5[α]D15 = −6.7 (c 0.26, MeOH)Source of chirality: asymmetric catalysisAbsolute configuration: (1R,3R,5R) (2R)
(3R,5R,7R)-Adamantan-1-yl (2R)-2-hydroxy-4-methoxy-1-oxo-2,3-dihydro-1H-indene-2-carboxylateC21H24O5[α]D15 = 4.7 (c 0.21, MeOH)Source of chirality: asymmetric catalysisAbsolute configuration: (1R,3R,5R) (2R)
Methyl (2R)-2-hydroxy-1-oxo-2,3-dihydro-1H-indene-2-carboxylateC11H10O4[α]D15 = −38.8 (c 0.66, MeOH)Source of chirality: asymmetric catalysisAbsolute configuration: (2R)
(3R,5R,7R)-Adamantan-1-yl (2R)-5-bromo-2-hydroxy-1-oxo-2,3-dihydro-1H-indene-2-carboxylateC20H21BrO4[α]D15 = −69.6 (c 0.52, MeOH)Source of chirality: asymmetric catalysisAbsolute configuration: (1R,3R,5R) (2R)
2,7-Dibromo-9H-fluoren-9-yl (2R)-2-hydroxy-1-oxo-2,3-dihydro-1H-indene-2-carboxylateC23H14Br2O4[α]D15 = −46.6 (c 0.61, MeOH)Source of chirality: asymmetric catalysisAbsolute configuration: (2R)
3-Ethylpentan-3-yl (2R)-2-hydroxy-1-oxo-2,3-dihydro-1H-indene-2-carboxylateC17H22O4[α]D15 = −66.8 (c 0.56, MeOH)Source of chirality: asymmetric catalysisAbsolute configuration: (2R)
(2S)-N-(tert-Butyl)-2-hydroxy-1-oxo-2,3-dihydro-1H-indene-2-carboxamideC14H17NO3[α]D15 = −6.3 (c 0.31, MeOH)Source of chirality: asymmetric catalysisAbsolute configuration: (2S)
(2S)-N-Isopropyl-2-hydroxy-1-oxo-2,3-dihydro-1H-indene-2-carboxamideC13H15NO3[α]D15 = +35.7 (c 0.58, MeOH)Source of chirality: asymmetric catalysisAbsolute configuration: (2S)
(2R)-N-(4-Fluorobenzyl)-2-hydroxy-1-oxo-2,3-dihydro-1H-indene-2-carboxamideC17H14FNO3[α]D15 = +86.4 (c 0.88, MeOH)Source of chirality: asymmetric catalysisAbsolute configuration: (2R)
(2S)-N-(3,5-Bis(trifluoromethyl)phenyl)-2-hydroxy-1-oxo-2,3-dihydro-1H-indene-2-carboxamideC18H11F6NO3[α]D15 = +76.5 (c 0.28, MeOH)Source of chirality: asymmetric catalysisAbsolute configuration: (2S)
(2S)-2-Hydroxy-1-oxo-N-(p-tolyl)-2,3-dihydro-1H-indene-2-carboxamideC17H15NO3[α]D15 = +57.3 (c 0.82, MeOH)Source of chirality: asymmetric catalysisAbsolute configuration: (2S)
(2S)-2-Hydroxy-1-oxo-N-(`o-tolyl)-2,3-dihydro-1H-indene-2-carboxamideC17H15NO3[α]D15 = +14.2 (c 0.76, MeOH)Source of chirality: asymmetric catalysisAbsolute configuration: (2S)
(2S)-5-Chloro-2-hydroxy-1-oxo-N-phenyl-2,3-dihydro-1H-indene-2-carboxamideC16H12ClNO3[α]D15 = +29.9 (c 0.53, MeOH)Source of chirality: asymmetric catalysisAbsolute configuration: (2S)
(1S,2R,4S,5R)-1-(Anthracen-9-ylmethyl)-2-((R)-hydroxy(6-methoxyquinolin-4-yl)methyl)-5-vinylquinuclidin-1-ium bromideC35H35BrN2O2[α]D15 = −214.3 (c 0.19, CH2Cl2)Source of chirality: the precursorAbsolute configuration: (2R)
(1S,2R,4S,5R)-1-Benzyl-2-((R)-hydroxy(6-((triisopropylsilyl)oxy)quinolin-4-yl)methyl)-5-vinylquinuclidin-1-ium bromideC35H49BrN2O2Si[α]D15 = −273.2 (c 0.16, CH2Cl2)Source of chirality: the precursorAbsolute configuration: (2R)
(1S,2R,4S,5R)-1-(Anthracen-9-ylmethyl)-2-((R)-hydroxy(6-isopropoxyquinolin-4-yl)methyl)-5-vinylquinuclidin-1-ium bromideC37H39BrN2O2[α]D15 = −396.6 (c 0.40, CH2Cl2)Source of chirality: the precursorAbsolute configuration: (2R)
(1S,2R,4S,5R)-1-(Anthracen-9-ylmethyl)-2-((R)-(6-(cyclopentyloxy)quinolin-4-yl)(hydroxy)methyl)-5-vinylquinuclidin-1-ium bromideC39H41BrN2O2[α]D15 = −444.5 (c 0.15, CH2Cl2)Source of chirality: the precursorAbsolute configuration: (2R)
(1S,2R,4S,5R)-2-((R)-Hydroxy(6-methoxyquinolin-4-yl)methyl)-1-((perfluorophenyl)methyl)-5-vinylquinuclidin-1-ium bromideC27H26BrF5N2O2[α]D15 = −46.2 (c 0.22, CH2Cl2)Source of chirality: the precursorAbsolute configuration: (2R)
(1S,2R,4S,5R)-1-(4-Fluorobenzyl)-2-((R)-hydroxy(6-methoxyquinolin-4-yl)methyl)-5-vinylquinuclidin-1-ium bromideC27H30BrFN2O2[α]D15 = −159.2 (c 0.18, CH2Cl2)Source of chirality: the precursorAbsolute configuration: (2R)
(1S,2R,4S,5R)-1-(4-Fluoro-2-(trifluoromethyl)benzyl)-2-((R)-hydroxy(6-methoxyquinolin-4-yl)methyl)-5-vinylquinuclidin-1-ium bromideC28H29BrF4N2O2[α]D15 = −189.5 (c 0.21, CH2Cl2)Source of chirality: the precursorAbsolute configuration: (2R)
(1S,2R,4S,5R)-1-(Anthracen-9-ylmethyl)-2-((R)-hydroxy(6-hydroxyquinolin-4-yl)methyl)-5-vinylquinuclidin-1-ium bromide bromideC34H33BrN2O2[α]D15 = −470.3 (c 0.21, CH2Cl2)Source of chirality: the precursorAbsolute configuration: (2R)
(1S,2R,4S,5R)-1-Benzyl-2-((R)-hydroxy(6-hydroxyquinolin-4-yl)methyl)-5-vinylquinuclidin-1-ium bromideC26H29BrN2O2[α]D15 = −199.3 (c 0.15, CH2Cl2)Source of chirality: the precursorAbsolute configuration: (2R)
(1S,2R,4S,5R)-2-((R)-Hydroxy(6-hydroxyquinolin-4-yl)methyl)-1-(3-(trifluoromethyl)benzyl)-5-vinylquinuclidin-1-ium bromideC27H28BrF3N2O2[α]D15 = −193.5 (c 0.17, CH2Cl2)Source of chirality: the precursorAbsolute configuration: (2R)
(1S,2R,4S,5R)-1-(3,5-Bis(trifluoromethyl)benzyl)-2-((R)-hydroxy(6-hydroxyquinolin-4-yl)methyl)-5-vinylquinuclidin-1-ium bromideC28H27BrF6N2O2[α]D15 = −177.3 (c 0.23, CH2Cl2)Source of chirality: the precursorAbsolute configuration: (2R)
(1S,2R,4S,5R)-1-(4-Fluorobenzyl)-2-((R)-hydroxy(6-hydroxyquinolin-4-yl)methyl)-5-vinylquinuclidin-1-ium bromideC26H28BrFN2O2[α]D15 = −212.2 (c 0.24, CH2Cl2)Source of chirality: the precursorAbsolute configuration: (2R)
(1S,2R,4S,5R)-2-((R)-Hydroxy(6-hydroxyquinolin-4-yl)methyl)-1-((perfluorophenyl)methyl)-5-vinylquinuclidin-1-ium bromideC26H24BrF5N2O2[α]D15 = −28.5 (c 0.20, CH2Cl2)Source of chirality: the precursorAbsolute configuration: (2R)
(1S,2R,4S,5R)-1-(4-Fluoro-2-(trifluoromethyl)benzyl)-2-((R)-hydroxy(6-hydroxyquinolin-4-yl)methyl)-5-vinylquinuclidin-1-ium bromideC27H27BrF4N2O2[α]D15 = −166.8 (c 0.29, CH2Cl2)Source of chirality: the precursorAbsolute configuration: (2R)
