The first primary amine-derived organocatalyst modified with an ionic group for asymmetric Michael reactions of C-nucleophiles with a,b-unsaturated ketones was synthesized. In the presence of this catalyst and an acidic co-catalyst (AcOH), hydroxycoumarin and its sulfur-containing analogue reacted with benzylideneacetone derivatives or cyclohexenone to afford the corresponding Michael adducts in high yields (up to 97%) and with reasonable enantioselectivity (up to 80%). The catalyst could be easily recovered and efficiently reused three times, afterwards, its activity and stereodifferentiating ability gradually declined. The analysis of recovered catalyst samples by ESI-MS allowed us to detect undesirable side reactions that poisoned the catalyst, and propose an approach for its reactivation.
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