| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1347159 | Tetrahedron: Asymmetry | 2009 | 6 Pages |
An investigation of the impact of oxygenated side chains in Ephedra compounds on the catalytic asymmetric addition of diethylzinc to aldehydes has been conducted. (1R,2S)-Ephedrine and (1S,2S)-pseudoephedrine were alkylated with either alkyl halides or β-alkoxyalkyl halides to afford a series of ligands 9a–h and 10a–h. These compounds were employed in the enantioselective addition of diethylzinc to a variety of aldehydes. It was determined that the presence of oxygen could have a negative effect in terms of obtaining high levels of enantiomeric discrimination, but the effect is diminished with higher levels of substitution near the oxygen.
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(1R,2S)-2-Butyl(methyl)amino)-1-phenylpropan-1-olC14H24NO[α]D25=-184 (c 0.71, CHCl3)Source of chirality: (1R,2S)-ephedrineAbsolute configuration: (1R,2S)
(1S,2S)-2-Butyl(methyl)amino)-1-phenylpropan-1-olC14H24NO[α]D25=-84 (c 0.85, CHCl3)Source of chirality: (1S,2S)-pseudoephedrineAbsolute configuration: (1S,2S)
(1R,2S)-2-((2-Methoxyethyl)(methyl)amino)-1-phenylpropan-1-olC13H22NO2[α]D25=-196 (c 0.71, CHCl3)Source of chirality: (1R,2S)-ephedrineAbsolute configuration: (1R,2S)
(1S,2S)-2-((2-Methoxyethyl)(methyl)amino)-1-phenylpropan-1-olC13H22NO2[α]D25=-553 (c 0.107, CHCl3)Source of chirality: (1S,2S)-pseudoephedrineAbsolute configuration: (1S,2S)
(1R,2S)-2-(Isobutyl(methyl)amino)-1-phenylpropan-1-olC14H24NO[α]D25=-165 (c 0.83, CHCl3)Source of chirality: (1R,2S)-ephedrineAbsolute configuration: (1R,2S)
(1S,2S)-2-(Isobutyl(methyl)amino)-1-phenylpropan-1-olC14H24NO[α]D25=-136 (c 0.61, CHCl3)Source of chirality: (1S,2S)-pseudoephedrineAbsolute configuration: (1S,2S)
(1R,2S)-2-((2-Ethylbutyl)(methyl)amino)-1-phenylpropan-1-olC16H28NO[α]D25=-225 (c 0.61, CHCl3)Source of chirality: (1R,2S)-ephedrineAbsolute configuration: (1R,2S)
(1S,2S)-2-((2-Ethylbutyl)(methyl)amino)-1-phenylpropan-1-olC16H28NO[α]D25=-166 (c 0.55, CHCl3)Source of chirality: (1S,2S)-pseudoephedrineAbsolute configuration: (1S,2S)
(1R,2S)-2-((2,2-Dimethoxyethyl)(methyl)amino)-1-phenylpropan-1-olC14H24NO3[α]D25=-337 (c 0.40, CHCl3)Source of chirality: (1R,2S)-ephedrineAbsolute configuration: (1R,2S)
(1S,2S)-2-((2,2-Dimethoxyethyl)(methyl)amino)-1-phenylpropan-1-olC14H24NO3[α]D25=-45.6 (c 1.13, CHCl3)Source of chirality: (1S,2S)-pseudoephedrineAbsolute configuration: (1S,2S)
(1R,2S)-2-((2,2-Diethoxyethyl)(methyl)amino)-1-phenylpropan-1-olC16H28NO3[α]D25=-170 (c 0.81, CHCl3)Source of chirality: (1R,2S)-ephedrineAbsolute configuration: (1R,2S)
(1S,2S)-2-((2,2-Diethoxyethyl)(methyl)amino)-1-phenylpropan-1-olC16H28NO3[α]D25=-138 (c 0.65, CHCl3)Source of chirality: (1S,2S)-pseudoephedrineAbsolute configuration: (1S,2S)
(1R,2S)-2-((Cyclopentylmethyl)(methyl)amino)-1-phenylpropan-1-olC16H26NO[α]D25=-211 (c 0.65, CHCl3)Source of chirality: (1R,2S)-ephedrineAbsolute configuration: (1R,2S)
(1S,2S)-2-((Cyclopentylmethyl)(methyl)amino)-1-phenylpropan-1-olC16H26NO[α]D25=-173 (c 0.52, CHCl3)Source of chirality: (1S,2S)-pseudoephedrineAbsolute configuration: (1S,2S)
(1R,2S)-2-(((1,3-Dioxolan-2-yl)methyl)(methyl)amino)-1-phenylpropan-1-olC14H24NO[α]D25=-126 (c 1.15, CHCl3)Source of chirality: (1R,2S)-ephedrineAbsolute configuration: (1R,2S)
(1R,2S)-2-(((1,3-Dioxolan-2-yl)methyl)(methyl)amino)-1-phenylpropan-1-olC14H24NO[α]D25=-51 (c 1.08, CHCl3)Source of chirality: (1R,2S)-ephedrineAbsolute configuration: (1R,2S)
