Asymmetric Organocatalytic Michael Addition of Pyrroles to Enones by Cinchona Alkaloid-Derived Primary Amines

Abstract

The enantioselective synthesis of 2-alkylated pyrroles via Michael addition of pyrroles to α,β-unsaturated ketones employing cinchona alkaloid-derived primary amines as organocatalysts is described. Good to excellent yields (78–99%) and good to very good enantioselectivities (75–93% ee) are obtained. With this protocol highly enantioenriched C-alkylated pyrroles can be synthesized easily, thus facilitating their possible application in medicinal chemistry.

Key words

organocatalysis - asymmetric synthesis - Michael addition - pyrrole - iminium activation

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