Lewis Basic Amine Catalyzed Aza-Michael Reaction of Indole- and Pyrrole-3-carbaldehydes

Abstract

3-Formyl substituted indoles or pyrroles can form HOMO-raised dearomative aza-dienamine-type intermediates with secondary amines, which can undergo direct aza-Michael addition to β-trifluoromethyl enones to afford N-alkylated products efficiently, albeit with low to fair enantioselectivity. In addition, similar asymmetric aza-Michael additions of these heteroarenes and crotonaldehyde are realized under dual catalysis of chiral amines, and the adducts are obtained with moderate to good enantioselectivity.

Key words

aza-Michael addition - aminocatalysis - dearomative transformations - aza-dienamine - dual catalysis

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