Asymmetric Michael addition
α,β-unsaturated carbonyl compound
Springer Online Journal Archives 1860-2000
Chemistry and Pharmacology
Abstract The asymmetric Michael addition of aromatic thiols to 2-cyclohexenone and maleic acid esters has been carried out by utilizing their crystalline cyclodextrin complexes suspended in water. The best chiral induction, 30% enantiomeric excess (ee), was achieved in combinations of 2-cyclohexenone and octyl maleate with the crystalline β-cyclodextrin complex of benzenethiol (method A) to afford (S)-3-phenylthiocyclohexanone and (S)-octyl-2-phenylthiosuccinate, respectively, whereas the reaction of benzenethiol with 2-cyclohexenone included in β-cyclodextrin (method B) inversely induced the chiral recognition to give the (R)-adduct with 4–9% ee.
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