| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1348305 | Tetrahedron: Asymmetry | 2011 | 5 Pages |
Unsymmetrical hybrid chiral ferrocenyl phosphine-phosphoramidite ligands have been applied for the first time in the Cu-catalyzed asymmetric 1,4-reduction of β-aryl substituted α,β-unsaturated esters. The results show that the ligand bearing (Sc)-central, (Rp)-planar, and (Ra)-axial chiralities gave the best performance. The present catalytic system proved to be highly substrate-dependent, catalyzing the conjugate reduction of α,β-unsaturated esters in moderate to excellent enantioselectivities.
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Ethyl (S)-3-phenylbutanoateC12H16O2Ee = 82%[α]D20=+9.3 (c 1.43, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (S)
Methyl (S)-3-phenylbutanoateC11H14O2Ee = 44%[α]D20=+7.3 (c 1.36, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (S)
iso-Propyl (S)-3-phenylbutanoateC13H18O2Ee = 50%[α]D20=+5.2 (c 1.28, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (S)
tert-Butyl (S)-3-phenylbutanoateC14H20O2Ee = 38%[α]D20=+8.3 (c 1.53, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (S)
Ethyl (S)-3-phenylpentanoateC13H18O2Ee = 86%[α]D20=+7.8 (c 1.18, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (S)
Ethyl (S)-4-methyl-3-phenylpentanoateC14H20O2Ee = 81%[α]D20=+13.4 (c 1.08, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: n.d.
Ethyl (S)-3-p-tolylbutanoateC13H18O2Ee = 77%[α]D20=+8.8 (c 1.48, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (S)
Ethyl (S)-3-(4-methoxyphenyl)butanoateC13H18O3Ee = 76%[α]D20=+11.6 (c 1.43, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: n.d.
Ethyl (S)-3-(4-chlorophenyl)butanoateC12H15ClO2Ee >99%[α]D20=+16.5 (c 1.27, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: n.d.
Ethyl (S)-3-(4-bromophenyl)butanoateC12H15BrO2Ee = 97%[α]D20=+9.9 (c 1.81, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: n.d.
Ethyl (S)-3-(4-nitrophenyl)butanoateC12H15NO4Ee = 80%[α]D20=+11.9 (c 1.63, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: n.d.
Ethyl (S)-3-(3-nitrophenyl)butanoateC12H15NO4Ee = 89%[α]D20=+3.6 (c 1.36, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: n.d.
Ethyl (S)-3-(thiophen-2-yl)butanoateC10H14SO2Ee = 83%[α]D20=+10.4 (c 1.51, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: n.d.
