Enantiopure trans-1-amino-2-(arylsulfanyl)cyclohexanes: novel chiral motifs for ligands and organocatalysts
作者:Anna E. Nowak、Elżbieta Wojaczyńska、Jacek Skarżewski
DOI:10.1016/j.tetasy.2011.09.015
日期:2011.9
In order to obtain the title compounds (1R,2R)-cyclohexane-1,2-diol was stereoselectively converted into cis-(1R,2S)-2-(arylsulfanyl)cyclohexanols and these products were submitted to the nucleophilic substitution via the Mitsunobu reaction (HN3, DEAD). Reduction of the isolated azides gave the desired trans-(1S,2S)-1-amino-2-(arylsulfanyl)cyclohexanes. The (1S,2S)-1-amino-2-(2-aminophenylsulfanyl)cyclohexanes thus prepared were reacted with 3,5-bis(trifluoromethyl)phenyl isothiocyanate to furnish the respective bis-thiourea compounds. An application of a derivative of this type as an organocatalyst (20 mol %) in the Baylis-Hillman reaction gave the respective product in up to 93% ee. (C) 2011 Elsevier Ltd. All rights reserved.