Resolution of Racemic 2-Aminocyclohexanol Derivatives and Their Application as Ligands in Asymmetric Catalysis

• DOI: 10.1021/jo052433w
• Publication Date: 2006-03-10T05:31:33Z
• Authors: Ingo Schiffers; Toni Rantanen; Frank Schmidt; Werner Bergmans; Lorenzo Zani; Carsten Bolm
• Keywords: Enantiopure drug; Mandelic acid; Transfer hydrogenation; Enantiomeric excess; Chiral resolution; Cyclohexanol

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 (R)- (S)-mandelic acid. simple aqueous workup procedure permits isolation amino alcohols in analytically pure form almost quantitative recovery mandelic Debenzylation enantiopure trans-2-(N-benzyl)amino-1-cyclohexanol hydrogenation subsequent derivatization give access to a broad variety diversely substituted derivatives. Furthermore, corresponding cis isomers are readily available. Applications these optically active aminocyclohexanols catalyzed asymmetric phenyl transfer reactions benzaldehydes hydrogenations aryl ketones lead products up 96% ee.