Asymmetric Henry reaction catalyzed by a copper tridentate chiral schiff-base complex

A series of copper-tridentate chiral Schiff-base complexes were prepared and employed in an asymmetric Henry reaction, affording the corresponding adducts in good yields and with high enantioselectivities (up to 96% ee).

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Complex 1aC58H50Cu2N2O4[α]D25=-258 (c 0.45, CH2Cl2)Source of chirality: phenylalanineAbsolute configuration: (2S)

(S)-1-(4-Nitrophenyl)-2-nitroethanolC8H8N2O5[α]D25=+35.9 (c 1.01, CH2Cl2)Source of chirality: copper trident chiral Schiff-base complexAbsolute configuration: (1S)

(S)-1-(2-Nitrophenyl)-2-nitroethanolC8H8N2O5[α]D25=+139.7 (c 0.61, CH2Cl2)Source of chirality: copper trident chiral Schiff-base complexAbsolute configuration: (1S)

(S)-1-(4-Chlorophenyl)-2-nitroethanolC8H8ClNO3[α]D25=+20.5 (c 1.12, CH2Cl2)Source of chirality: copper trident chiral Schiff-base complexAbsolute configuration: (1S)

(S)-1-(3-Chlorophenyl)-2-nitroethanolC8H8ClNO3[α]D25=+82.1 (c 0.57, CH2Cl2)Source of chirality: copper trident chiral Schiff-base complexAbsolute configuration: (1S)

(S)-1-(2-Chlorophenyl)-2-nitroethanolC8H8ClNO3[α]D25=+46.3 (c 1.07, CH2Cl2)Source of chirality: copper trident chiral Schiff-base complexAbsolute configuration: (1S)

(S)-1-Phenyl-2-nitroethanolC8H9NO3[α]D25=+38.1 (c 0.98, CH2Cl2)Source of chirality: copper trident chiral Schiff-base complexAbsolute configuration: (1S)

(S)-2-Nitro-1-p-tolylethanolC9H11NO3[α]D25=+23.4 (c 1.12, CH2Cl2)Source of chirality: copper trident chiral Schiff-base complexAbsolute configuration: (1S)

(S)-2-Nitro-1-o-tolylethanolC9H11NO3[α]D25=+51.2 (c 1.01, CH2Cl2)Source of chirality: copper trident chiral Schiff-base complexAbsolute configuration: (1S)

(S)-1-(4-Methoxyphenyl)-2-nitroethanolC9H11NO4[α]D25=+29.0 (c 2.03, CH2Cl2)Source of chirality: copper trident chiral Schiff-base complexAbsolute configuration: (1S)

(S)-1-(2-Methoxyphenyl)-2-nitroethanolC9H11NO4[α]D25=+43.6 (c 1.05, CH2Cl2)Source of chirality: copper trident chiral Schiff-base complexAbsolute configuration: (1S)

(S)-1-(1-Naphthyl)-2-nitroethanolC12H11NO3[α]D25=+24.1 (c 1.06, CH2Cl2)Source of chirality: copper trident chiral Schiff-base complexAbsolute configuration: (1S)

(S)-1-Nitro-3-phenylpropan-2-olC9H11NO3[α]D25=-43.4 (c 2.17, CH2Cl2)Source of chirality: copper trident chiral Schiff-base complexAbsolute configuration: (2S)

(S)-4-Methyl-1-nitropentan-2-olC6H13NO3[α]D25=-15.8 (c 2.12, CH2Cl2)Source of chirality: copper trident chiral Schiff-base complexAbsolute configuration: (2S)

(S)-1-Nitropentan-2-olC5H11NO3[α]D25=-53.2 (c 0.81, CH2Cl2)Source of chirality: copper trident chiral Schiff-base complexAbsolute configuration: (2S)

2-(((S)-1-Hydroxy-1,1,3-triphenylpropan-2-ylimino)methyl)-6-methylphenolC29H27NO2[α]D25=-53.2 (c 0.81, CH2Cl2)Source of chirality: phenylalanineAbsolute configuration: (2S)

2-(((S)-1-Hydroxy-1,1,3-triphenylpropan-2-ylimino)methyl)-4-methylphenolC29H27NO2[α]D25=-72.0 (c 1.01, CH2Cl2)Source of chirality: phenylalanineAbsolute configuration: (2S)

2-(((S)-1-Hydroxy-1,1,3-triphenylpropan-2-ylimino)methyl)-6-ethylphenolC30H29NO2[α]D25=-50.2 (c 0.96, CH2Cl2)Source of chirality: phenylalanineAbsolute configuration: (2S)

2-(((S)-1-Hydroxy-1,1,3-triphenylpropan-2-ylimino)methyl)-6-isopropylphenolC31H31NO2[α]D25=-53.2 (c 0.81, CH2Cl2)Source of chirality: phenylalanineAbsolute configuration: (2S)

2-(((S)-1-Hydroxy-1,1,3-triphenylpropan-2-ylimino)methyl)-6-tert-butylphenolC32H33NO2[α]D25=-71.0 (c 0.97, CH2Cl2)Source of chirality: phenylalanineAbsolute configuration: (2S)

2-(((S)-1-Hydroxy-1,1,3-triphenylpropan-2-ylimino)methyl)-4-tert-butylphenolC32H33NO2[α]D25=-71.3 (c 0.88, CH2Cl2)Source of chirality: phenylalanineAbsolute configuration: (2S)

2-(((S)-1-Hydroxy-1,1,3-triphenylpropan-2-ylimino)methyl)-6-methoxyphenolC29H27NO3[α]D25=-56.1 (c 0.67, CH2Cl2)Source of chirality: phenylalanineAbsolute configuration: (2S)

2-(((S)-1-Hydroxy-1,1,3-triphenylpropan-2-ylimino)methyl)-4-methoxyphenolC29H27NO3[α]D25=-54.0 (c 0.68, CH2Cl2)Source of chirality: phenylalanineAbsolute configuration: (2S)

2-(((S)-1-Hydroxy-1,1,3-triphenylpropan-2-ylimino)methyl)-6-chlorophenolC28H24ClNO2[α]D25=-58.1 (c 0.90, CH2Cl2)Source of chirality: phenylalanineAbsolute configuration: (2S)

2-(((S)-1-Hydroxy-1,1,3-triphenylpropan-2-ylimino)methyl)-4-chlorophenolC28H24ClNO2[α]D25=-33.5 (c 0.78, CH2Cl2)Source of chirality: phenylalanineAbsolute configuration: (2S)