| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1344498 | Tetrahedron: Asymmetry | 2011 | 9 Pages |
A series of (1S,1′S)-4,4′-biquinazoline-based primary amines were prepared from natural amino acids via a six-step reaction sequence of protection and condensation followed by key synthetic steps including chlorination, nickel(0)-mediated homocoupling, and deprotection. These novel amines were screened for the asymmetric ethylation of aryl aldehydes to yield alcohols with an (S)-configuration with enantiomeric excesses (ee) varying from 2% to 95%.
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(S)-tert-butyl 1-(2-carbamoylphenylamino)-1-oxopropan-2-ylcarbamateC15H21N3O4Ee: 99%Source of chirality: l-alanineAbsolute configuration: (S)[α]D20=-66.3 (c 1, EtOH)
(S)-tert-butyl 1-(2-carbamoylphenylamino)-3-methyl-1-oxobutan-2-ylcarbamateC17H25N3O4Ee: 99%Source of chirality: l-valineAbsolute configuration: (S)[α]D20=-62 (c 1, EtOH)
(S)-tert-butyl 1-(2-carbamoylphenylamino)-3,3-dimethyl-1-oxobutan-2-ylcarbamateC18H27N3O4Ee: 99%Source of chirality: l-tert-leucineAbsolute configuration: (S)[α]D20=-43 (c 1, EtOH)
(S)-tert-butyl 1-(2-carbamoylphenylamino)-1-oxo-3-phenylpropan-2-ylcarbamateC21H25N3O4Ee: 99%Source of chirality: l-phenylalanineAbsolute configuration: (S)[α]D20=-48 (c 1, EtOH)
(S)-tert-butyl 1-(4-oxo-3,4-dihydroquinazolin-2-yl)ethylcarbamateC15H19N3O3Ee: 99%Source of chirality: l-alanineAbsolute configuration: (S)[α]D20=-58 (c 1, EtOH)
(S)-tert-butyl 2-methyl-1-(4-oxo-3,4-dihydroquinazolin-2-yl)propylcarbamateC17H23N3O3Ee: 99%Source of chirality: l-valineAbsolute configuration: (S)[α]D20=-69 (c 1, EtOH)
(S)-tert-butyl 2,2-dimethyl-1-(4-oxo-3,4-dihydroquinazolin-2-yl)propylcarbamateC18H25N3O3Ee: 99%Source of chirality: l-tert-LeucineAbsolute configuration: (S)[α]D20=-91 (c 1, DCM)
(S)-tert-butyl 1-(4-oxo-3,4-dihydroquinazolin-2-yl)-2-phenylethylcarbamateC21H23N3O3Ee: 99%Source of chirality: l-phenylalanineAbsolute configuration: (S)[α]D20=-41 (c 1, DCM)
(S)-tert-butyl 1-(4-chloroquinazolin-2-yl)ethylcarbamateC15H18ClN3O2Ee: 99%Source of chirality: l-alanineAbsolute configuration: (S)[α]D20=-54.1 (c 1.6, DCM)
(S)-tert-butyl 1-(4-chloroquinazolin-2-yl)-2-methylpropylcarbamateC17H22ClN3O2Ee: 99%Source of chirality: l-valineAbsolute configuration: (S)[α]D20=-52.9 (c 1.1, DCM)
(S)-tert-butyl 1-(4-chloroquinazolin-2-yl)-2,2-dimethylpropylcarbamateC18H24ClN3O2Ee: 99%Source of chirality: l-tert-leucineAbsolute configuration: (S)[α]D20=-53.4 (c 1.1, DCM)
(S)-tert-butyl 1-(4-chloroquinazolin-2-yl)-2-phenylethylcarbamateC21H22ClN3O2Ee: 99%Source of chirality: l-phenylalanineAbsolute configuration: (S)[α]D20=-46.5 (c 1.3, DCM)
tert-butyl (1S,1′S)-1,1′-(4,4′-biquinazoline-2,2′-diyl)bis(ethane-1,1-diyl)dicarbamateC30H36N6O4Ee: 99%Source of chirality: l-alanineAbsolute configuration: (S)[α]D20=-49.0 (c 1, DCM)
tert-butyl (1S,1′S)-1,1′-(4,4′-biquinazoline-2,2′-diyl)bis(2-methylpropane-1,1-diyl)dicarbamateC34H44N6O4Ee: 99%Source of chirality: l-valineAbsolute configuration: (S)[α]D20=-55 (c 1, EtOH)
tert-butyl (1S,1′S)-1,1′-(4,4′-biquinazoline-2,2′-diyl)bis(2,2-dimethylpropane-1,1-diyl)dicarbamateC36H48N6O4Ee: 99%Source of chirality: l-tert-leucineAbsolute configuration: (S)[α]D20=-36.5 (c 1, EtOH)
tert-butyl (1S,1′S)-1,1′-(4,4′-biquinazoline-2,2′-diyl)bis(2-phenylethane-1,1-diyl)dicarbamateC42H44N6O4Ee: 99%Source of chirality: l-phenylalanineAbsolute configuration: (S)[α]D20=-109.0 (c 1, DCM)
(1S,1′S)-1,1′-(4,4′-biquinazoline-2,2′-diyl)diethanamineC20H20N6Ee: 99%Source of chirality: l-alanineAbsolute configuration: (S)[α]D20=+16.5 (c 1, DCM)
(1S,1′S)-1,1′-(4,4′-biquinazoline-2,2′-diyl)bis(2-methylpropan-1-amine)C24H28N6Ee: 99%Source of chirality: l-valineAbsolute configuration: (S)[α]D20=+50.0 (c 1, DCM)
(1S,1′S)-1,1′-(4,4′-biquinazoline-2,2′-diyl)bis(2,2-dimethylpropan-1-amine)C26H32N6Ee: 99%Source of chirality: l-tert-leucineAbsolute configuration: (S)[α]D20=+161.0 (c 1, DCM)
(1S,1′S)-1,1′-(4,4′-biquinazoline-2,2′-diyl)bis(2-phenylethanamine)C32H28N6Ee: 99%Source of chirality: l-phenylalanineAbsolute configuration: (S)[α]D20=+71.0 (c 1, DCM)
