Resolution of racemic 2-aminocyclohexanol derivatives and their application as ligands in asymmetric catalysis.
J Org Chem
; 71(6): 2320-31, 2006 Mar 17.
Article
in En
| MEDLINE
| ID: mdl-16526780
ABSTRACT
A preparatively easy and efficient protocol for the resolution of racemic 2-aminocyclohexanol derivatives is described, delivering both enantiomers with >99% enantiomeric excess (ee) by sequential use of (R)- and (S)-mandelic acid. A simple aqueous workup procedure permits the isolation of the amino alcohols in analytically pure form and the almost quantitative recovery of mandelic acid. Debenzylation of enantiopure trans-2-(N-benzyl)amino-1-cyclohexanol by hydrogenation and subsequent derivatization give access to a broad variety of diversely substituted derivatives. Furthermore, the corresponding cis isomers are readily available. Applications of these optically active aminocyclohexanols in catalyzed asymmetric phenyl transfer reactions to benzaldehydes and transfer hydrogenations of aryl ketones lead to products with up to 96% ee.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Benzaldehydes
/
Cyclohexanols
/
Alcohols
Language:
En
Journal:
J Org Chem
Year:
2006
Type:
Article
Affiliation country:
Germany