Conjugate addition of 1,3-dicarbonyl compounds to maleimides using a chiral C2-symmetric bis(2-aminobenzimidazole) as recyclable organocatalyst

Org Lett. 2011 Nov 18;13(22):6106-9. doi: 10.1021/ol202599h. Epub 2011 Oct 26.

Abstract

The recyclable chiral 2-aminobenzimidazole-derived organocatalyst 1f efficiently promotes the room temperature asymmetric conjugate addition of 1,3-diketones, β-ketoesters, and malonates to maleimide and N-substituted maleimides, affording the corresponding Michael adducts in excellent yields and enantioselectivities even at gram scale.