| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1347609 | Tetrahedron: Asymmetry | 2008 | 9 Pages |
A series of new chiral palladium-bisphosphinite complexes have been prepared from readily available, naturally occurring chiral alcohols. The complexes were used to efficiently carry out catalytic allylic alkylation of 1,3-diphenylpropene-2-yl acetate with dimethyl malonate. The complexes based on derivatives of ascorbic acid carry out enantioselective alkylations, one of which showed an ee as high as 97%. Based on the structural characterization, it can be surmised that strategic placement of phenyl groups is key to higher enantioselectivities.
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[(2R,3R)-Diethyl 2,3-bis(diphenylphosphinooxy) succinate PdCl2]C32H32P2O6PdCl2[α]D25=+59.2 (c 1.0, CHCl3)Source of chirality: l-tartaric acidAbsolute configuration: (2R,3R)
[(2S,3S)-Diethyl 2,3-bis(diphenylphosphinooxy) succinate PdCl2]C32H32P2O6PdCl2[α]D25=-52.9 (c 1.0, CH2Cl2)Source of chirality: d-tartaric acidAbsolute configuration: (2S,3S)
[(1R,2R)-1,2-Bis(diphenylphosphinooxy)-1,2-diphenylethane PdCl2]C38H32P2O2PdCl2[α]D25=-9.9 (c 2, CHCl3)Source of chirality: (R,R)-hydrobenzoinAbsolute configuration: (1R,2R)
[(S)-1,2-Bis(diphenylphosphinooxy)-1,1,2-triphenylethane PdCl2]C44H36P2O2PdCl2[α]D25=+12.8 (c 2, CH2Cl2)Source of chirality: (S)-(+)-1,1,2-triphenylethanolAbsolute configuration: (S)
[(3S,6S)-3,6-Bis(diphenylphosphinooxy)-hexahydrofuro[3,2-b]furan PdCl2]C30H28P2O4PdCl2[α]D25=+28.2 (c 1, CHCl3)Source of chirality: isomannideAbsolute configuration: (3S,6S)
[N-((1R,2R)-1,3-Bis(benzhydryloxy)-1-(4-nitrophenyl)propan-2-yl)-2,2-dichloroacetamide PdCl2]C35H30P2N2O5PdCl4[α]D25=+57.3 (c 1, DMSO)Source of chirality: chloramphenicolAbsolute configuration: (R,R)
[(R)-4-((1S,2R)-2-((S)-2,2-Dimethyl-1,3-dioxolan-4-yl)-1,2-bis(diphenylphosphinooxy)ethyl)-2,2-dimethyl-1,3-dioxolane PdCl2]C36H40P2O6PdCl2[α]D25=+28.4 (c 0.5, CHCl3)Source of chirality: d-mannitolAbsolute configuration: (R,S,R,S)
[(R)-5-((S)-1,2-Bis(diphenylphosphinooxy)ethyl)-3,4-dihydroxyfuran-2(5H)-one PdCl2]C30H26P2O6PdCl2[α]D25=+21.2 (c 1, DMSO)Source of chirality: ascorbic acidAbsolute configuration: (R,S)
[(R)-5-((S)-1,2-Bis(diphenylphosphinooxy)ethyl)-3-(benzyloxy)-4-hydroxyfuran-2(5H)-one PdCl2]C37H32P2O6PdCl2[α]D25=+19.9 (c 1.6, CH2Cl2)Source of chirality: ascorbic acidAbsolute configuration: (R,S)
[(R)-5-((S)-1,2-Bis(diphenylphosphinooxy)ethyl)-4-(benzyloxy)-4-hydroxyfuran-2(5H)-one PdCl2]C37H32P2O6PdCl2[α]D25=+31.2 (c 1.8, CHCl3)Source of chirality: ascorbic acidAbsolute configuration: (R,S)
[(R)-5-((S)-1,2-Bis(diphenylphosphinooxy)ethyl)-3,4-bis(benzyloxy)furan-2(5H)-one PdCl2]C44H38P2O6PdCl2[α]D25=+42.1 (c 1.4, CHCl3)Source of chirality: ascorbic acidAbsolute configuration: (R,S)
[(R)-5-((R)-1,2-Bis(diphenylphosphinooxy)ethyl)-3,4-dihydroxyfuran-2(5H)-one PdCl2]C30H26P2O6PdCl2[α]D25=-18.6 (c 0.6, DMSO)Source of chirality: isoascorbic acidAbsolute configuration: (R,R)
[(R)-5-((R)-1,2-Bis(diphenylphosphinooxy)ethyl)-3-(benzyloxy)-4-hydroxyfuran-2(5H)-one PdCl2]C37H32P2O6PdCl2[α]D25=-23.6 (c 1.1, CHCl3)Source of chirality: isoascorbic acidAbsolute configuration: (R,R)
[(R)-5-((R)-1,2-Bis(diphenylphosphinooxy)ethyl)-4-(benzyloxy)-4-hydroxyfuran-2(5H)-one PdCl2]C37H32P2O6PdCl2[α]D25=-37.3 (c 1.8, CH2Cl2)Source of chirality: isoascorbic acidAbsolute configuration: (R,R)
[(R)-5-((R)-1,2-Bis(diphenylphosphinooxy)ethyl)-3,4-bis(benzyloxy)furan-2(5H)-one PdCl2]C44H38P2O6PdCl2[α]D25=-33.9 (c 2.0, CHCl3)Source of chirality: isoascorbic acidAbsolute configuration: (R,R)
