| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1348871 | Tetrahedron: Asymmetry | 2010 | 10 Pages |
Planar chirality has been introduced into chiral ferrocenecarboxamides via an amide-directed ortho-lithiation with diastereoselectivity of up to 99%. The use of an easily accessible, camphane-based chiral auxiliary as an ortho-directing group led to single diastereoisomers with a variety of electrophiles. The approach allows the preparation of widely applicable ferrocene derivatives.
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N-((1S,2R,3S,4R)-3-Ethoxy-4,7,7-trimethylbicyclo[2.2.1]heptan-2-yl)-N-ethylferrocenecarboxamideC25H35FeNO2Ee >99%[α]D = +36.2 (c 0.38, CHCl3)Source of chirality: (+)-camphorAbsolute configuration: (1S,2R,3S,4R)
(Rp)-2-Methyl-N-((1S,2R,3S,4R)-3-ethoxy-4,7,7-trimethylbicyclo[2.2.1]heptan-2-yl)-N-ethylferrocenecarboxamideC26H37FeNO2De = 96% (NMR, CSP HPLC)[α]D = +113.8 (c 0.41, CHCl3)Source of chirality: (+)-camphorAbsolute configuration: (1S,2R,3S,4R,Rp)
(Sp)-N-((1S,2R,3S,4R)-3-Ethoxy-4,7,7-trimethylbicyclo[2.2.1]heptan-2-yl)-N-ethyl-2-(trimethylsilyl)ferrocenecarboxamideC28H43FeNO2SiDe >99% (NMR, CSP HPLC)[α]D = +117.3 (c 0.66, CHCl3)Source of chirality: (+)-camphorAbsolute configuration: (1S,2R,3S,4R,Sp)
(Rp)-N-((1S,2R,3S,4R)-3-Ethoxy-4,7,7-trimethylbicyclo[2.2.1]heptan-2-yl)-N-ethyl-2-(hydroxydiphenylmethyl)ferrocenecarboxamideC38H45FeNO3De >99% (NMR, CSP HPLC)[α]D = +111.7 (c 0.46, CHCl3)Source of chirality: (+)-camphorAbsolute configuration: (1S,2R,3S,4R,Rp)
(Sp)-N-((1S,2R,3S,4R)-3-Ethoxy-4,7,7-trimethylbicyclo[2.2.1]heptan-2-yl)-N-ethyl-2-iodoferrocenecarboxamideC25H34FeINO2De >99% (NMR)[α]D = +46.9 (c 0.72, CHCl3)Source of chirality: (+)-camphorAbsolute configuration: (1S,2R,3S,4R,Sp)
(Sp)-2-(Diphenylphosphino)-N-((1S,2R,3S,4R)-3-ethoxy-4,7,7-trimethylbicyclo[2.2.1]heptan-2-yl)-N-ethylferrocenecarboxamideC37H44FeNO2PDe >99% (NMR)[α]D = −213.8 (c 0.57, CHCl3)Source of chirality: (+)-camphorAbsolute configuration: (1S,2R,3S,4R,Sp)
