| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1347614 | Tetrahedron: Asymmetry | 2008 | 6 Pages |
A pentafluorophenyl group embedded in a chiral diamine allows the direct modification of an aryl group. The diamine is readily converted into para-disubstituted diamines. Although the electronic effect of the modified diamine somewhat lowers the catalytic activity of BINAP–Ru–diamine-catalyzed asymmetric hydrogenation, the enantioselectivity of the product is higher than that obtained by using a typical chiral diamine. Such an easy and direct modification of the chiral ligand has the potential to facilitate the optimization of the steric effect of chiral ligands in asymmetric catalysis.
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(1S,2S)-1,2-Bis(4-methoxy-2,3,5,6-tetrafluorophenyl)ethane-1,2-diamineC16H12F8N2O2Ee >99%[α]D20=-85.8 (c 0.50, MeOH)Source of chirality: enantiopure starting materialAbsolute configuration: (1S,2S)
(1S,2S)-1,2-Bis(4-isopropoxy-2,3,5,6-tetrafluorophenyl)ethane-1,2-diamineC20H20F8N2O2Ee >99%[α]D30=-92.5 (c 0.21, MeOH)Source of chirality: enantiopure starting materialAbsolute configuration: (1S,2S)
(1S,2S)-1,2-Bis(4-(pentan-3-yloxy)-2,3,5,6-tetrafluorophenyl)ethane-1,2-diamineC24H28F8N2O2Ee >99%[α]D16=-51.4 (c 1.6, MeOH)Source of chirality: enantiopure starting materialAbsolute configuration: (1S,2S)
(1S,2S)-1,2-Bis(4-benzhydryloxy-2,3,5,6-tetrafluorophenyl)ethane-1,2-diamineC40H28F8N2O2Ee >99%[α]D32=-41.9 (c 0.19, MeOH)Source of chirality: enantiopure starting materialAbsolute configuration: (1S,2S)
(1S,2S)-1,2-Bis(4-neopentyloxy-2,3,5,6-tetrafluorophenyl)ethane-1,2-diamineC24H28F8N2O2Ee >99%[α]D30=-89.2 (c 0.45, MeOH)Source of chirality: enantiopure starting materialAbsolute configuration: (1S,2S)
(1S,2S)-1,2-Bis(4-cyclopentyloxy-2,3,5,6-tetrafluorophenyl)ethane-1,2-diamineC24H24F8N2O2Ee >99%[α]D31=-77.2 (c 0.54, MeOH)Source of chirality: enantiopure starting materialAbsolute configuration: (1S,2S)
(1S,2S)-1,2-Bis(4-cyclohexyloxy-2,3,5,6-tetrafluorophenyl)ethane-1,2-diamineC26H28F8N2O2Ee >99%[α]D32=-80.2 (c 0.13, MeOH)Source of chirality: enantiopure starting materialAbsolute configuration: (1S,2S)
(1S,2S)-1,2-Bis(2,3,5,6-tetrafluoro-4-(3,3,5,5-tetramethylcyclohexyloxy)phenyl)ethane-1,2-diamineC34H44F8N2O2Ee >99%[α]D32=-95.8 (c 0.78, MeOH)Source of chirality: enantiopure starting materialAbsolute configuration: (1S,2S)
(1S,2S)-1,2-Bis(4-(2,3-dihydro-1H-inden-2-yloxy)-2,3,5,6-tetrafluorophenyl)ethane-1,2-diamineC32H24F8N2O2Ee >99%[α]D32=-72.8 (c 0.18, MeOH)Source of chirality: enantiopure starting materialAbsolute configuration: (1S,2S)
(1S,2S)-1,2-Bis(4-((S)-1-phenylethoxy)-2,3,5,6-tetrafluorophenyl)ethane-1,2-diamineC30H24F8N2O2Ee >99%[α]D32=-177.3 (c 0.23, MeOH)Source of chirality: enantiopure starting materialAbsolute configuration: (1S,2S)
(1S,2S)-1,2-Bis(4-((R)-1-phenylethoxy)-2,3,5,6-tetrafluorophenyl)ethane-1,2-diamineC30H24F8N2O2Ee >99%[α]D32=+63.9 (c 0.55, MeOH)Source of chirality: enantiopure starting materialAbsolute configuration: (1S,2S)
(1S,2S)-1,2-Bis(2,3,5,6-tetrafluorophenyl)ethane-1,2-diamineC14H8F8N2Ee >99%[α]D18=-61.9 (c 1.8, MeOH)Source of chirality: enantiopure starting materialAbsolute configuration: (1S,2S)
