| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1349046 | Tetrahedron: Asymmetry | 2010 | 9 Pages |
(1S,2S)-Pseudoephedrine and (1S,2S)-pseudonorephedrine have been converted to their corresponding hydrazines and condensed with either o-salicylaldehyde or 2-hydroxy-1-naphthaldehyde to afford a series of β-hydroxysalicylhydrazones that have been employed in the asymmetric addition of diethylzinc to 2-naphthaldehyde in up to 56% ee. In addition to this, the Ephedra hydrazines were also condensed with the o-hydroxyacetophenone derivative to form related hydrazones. The use of these corresponding hydrazones in the asymmetric addition reaction with the diethylzinc did not yield improved enantioselectivities. Finally, Enders’ hydrazine was used as a chiral scaffold for the synthesis of β-methoxysalicylhydrazones. These compounds were employed in the asymmetric addition of diethylzinc to a variety of aromatic aldehydes with enantiomeric excesses as high as 68% ee.
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1-((E)-(2-((1S,2S)-1-Hydroxy-1-phenyl-2-propyl-2-methylhydrazono) methyl)-2-naphtholC21H22N2O2White solid[α]D20=-29.5 (c 1.0, CHCl3)Source of chirality: (1S,2S)-pseudoephedrineAbsolute configuration: (1S,2S)
2-((E)-(2-((1S,2S)-1-Hydroxy-1-phenyl-2-propyl)-2-methylhydrazono)methyl)phenolC17H20N2O2White solid[α]D20=-13.9 (c 1.0, CHCl3)Source of chirality: (1S,2S)-pseudoephedrineAbsolute configuration: (1S,2S)
(1S,2S)-2-(Isopropylamino)-1-phenylpropan-1-olC12H19N2OLight yellow oil[α]D25=+53.6 (c 0.5, CHCl3)Source of chirality: (1S,2S)-pseudonorephedrineAbsolute configuration: (1S,2S)
N-((1S,2S)-1-Hydroxy-1-phenylpropan-2-yl)-N-isopropylnitrous amideC12H18N2O2White solid[α]D25=+188.0 (c 0.2, CHCl3)Source of chirality: (1S,2S)-pseudonorephedrineAbsolute configuration: (1S,2S)
1-((E)-(2-((1S,2S)-1-Hydroxy-1-phenylpropan-2-yl)-2-isopropylhydrazono)methyl)naphthalen-2-olC23H26N2O2Yellow liquid[α]D25=+43.4 (c 1.0, CHCl3)Source of chirality: (1S,2S) pseudonorephedrineAbsolute configuration: (1R,2S)
2-((E)-(2-((1S,2S)-1-Hydroxy-1-phenylpropan-2-yl)-2-isopropylhydrazono)methyl)phenolC19H204N2O2Yellow liquid[α]D23=+17.1 (c 1.0, CHCl3)Source of chirality: (1S,2S) pseudonorephedrineAbsolute configuration: (1S,2S)
(1S,2S)-2-(Benzylamino)-1-phenylpropan-1-olC16H19NOWhite solid[α]D25=+135.9 (c 1.0, CHCl3)Source of chirality: (1S,2S) pseudonorephedrineAbsolute configuration: (1S,2S)
N-Benzyl-N-((1S,2S)-1-hydroxy-1-phenylpropan-2-yl)nitrous amideC16H18N2O2White solid[α]D25=+204.7 (c 1.0, CHCl3)Source of chirality: (1S,2S)-pseudonorephedrineAbsolute configuration: (1S,2S)
1-((E)-(2-Benzyl-2-((1S,2S)-1-hydroxy-1-phenylpropan-2-yl)hydrazono)methyl)naphthalen-2-olC27H26N2O2White solid[α]D25=+11.5 (c 1.0, CHCl3)Source of chirality: (1S,2S)-pseudonorephedrineAbsolute configuration: (1S,2S)
N-((1R,2S)-2-Hydroxy-2,3-dihydro-1H-inden-1-yl)-N-methylnitrous amideC10H12N2O2Yellow solid[α]D24=+60.4 (c 1.1, CHCl3)Source of chirality: (1R,2S)-cis-1-amino-2-indanolAbsolute configuration: (1R,2S)
Methyl (1R,2S)-2-Hydroxy-2,3-dihydro-1H-inden-1-ylcarbamateC11H13NO3White solid[α]D23=+19.1 (c 1.0, CHCl3)Source of chirality: (1R,2S)-cis-1-amino-2-indanolAbsolute configuration: (1R,2S)
(1R,2S)-1-(Methylamino)-2,3-dihydro-1H-inden-2-olC10H13NOOffwhite solid[α]D24=-10.2 (c 1.0, CHCl3)Source of chirality: (1R,2S)-cis-1-amino-2-indanolAbsolute configuration: (1R,2S)
N-((1R,2S)-2-Hydroxy-2,3-dihydro-1H-inden-1-yl)-N-methylnitrous amideC10H12N2O2Yellow solid[α]D24=+60.4 (c 1.1, CHCl3)Source of chirality: (1R,2S)-cis-1-amino-2-indanolAbsolute configuration: (1R,2S)
(1R,2S)-1-(1-Methylhydrazinyl)-2,3-dihydro-1H-inden-2-olC21H20N2O2Light brown solid[α]D23=+122.7 (c 0.2, CHCl3)Source of chirality: (1R,2S)-cis-1-amino-2-indanolAbsolute configuration: (1R,2S)
2-((E)-1-(2-((1S,2S)-1-Hydroxy-1-phenylpropan-2-yl)-2-methylhydrazono)ethyl)-4-methylphenolC19H24N2O2Yellow liquid[α]D25=-371.9 (c 1.1, CHCl3)Source of chirality: (1S,2S)-pseudoephedrineAbsolute configuration: (1S,2S)
2-((E)-1-(2-((1R,2S)-1-Hydroxy-1-phenyl-2-propyl)-2-methylhydrazono)ethyl)-4-methylphenolC19H24N2O2Yellow solid[α]D25=+59.6 (c 1.0, CHCl3)Source of chirality: (1R,2S)-ephedrineAbsolute configuration: (1R,2S)
1-((2-((1R,2S)-1-Hydroxy-1-phenyl-2-propyl)-2-methylhydrazinyl)methyl)-2-naphtholC21H24N2O2Offwhite solid[α]D24=+123.4 (c 0.3, CHCl3)Source of chirality: (1R,2S)-ephedrineAbsolute configuration: (1R,2S)
((1R,2S)-2-((E)-1-Methyl-2-(naphthalen-1-ylmethylene)hydrazinyl)-1-phenyl-1-propanolC21H22N2OWhite solid[α]D24=+169.5 (c 1.0, CHCl3)Source of chirality: (1R,2S)-ephedrineAbsolute configuration: (1R,2S)
(1R,2S)-2-(1-Methyl-2-(naphthalen-1-ylmethyl)hydrazinyl)-1-phenyl-1-propanolC21H24N2OWhite solid[α]D25=+43.4 (c 1.0, CHCl3)Source of chirality: (1R,2S)-ephedrineAbsolute configuration: (1R,2S)
(S,E)-2-((2-(Methoxymethyl)pyrrolidin-1-ylimino)methyl)phenolC13H18N2O2Yellow liquid[α]D23=-202.9 (c 1.1, CHCl3)Source of chirality: (S)-Enders’ hydrazine (SAMP)Absolute configuration: (S)
(S,E)-1-((2-(Methoxymethyl)pyrrolidin-1-ylimino)methyl)-2-naphtholC17H20N2O2Yellow solid[α]D23=-225.6 (c 1, CHCl3)Source of chirality: (S)-Enders’ hydrazine (SAMP)Absolute configuration: (S)
(S,E)-2,4-Di-tert-butyl-6-((2-(methoxymethyl)pyrrolidin-1-ylimino)methyl)phenolC21H34N2O2Yellow solid[α]D23=-126.5 (c 1, CHCl3)Source of chirality: (S)-Enders’ hydrazine (SAMP)Absolute configuration: (S)
