Imidazolidin cascade reactions

Different polymer-supported imidazolidin-4-ones have been deployed in cascade reactions. This strategy was successfully tested in a double Michael addition of methylindole, 2-hexenal, and vinyl methyl ketone [112]. 

The discovery of two discrete amine catalysts that can increase selectivities in each step of this cascade reaction represents a further milestone of this development and has led to a more modulated stereoselective application of these cascade reactions. Practically enantiomerically pure syn- or onti-configured aldehydes can be accessed by a careful combination of two different imidazolidin-4-ones. The usefulness of this concept was demonstrated by the MacMillan group in several important transformations. 

Namitharan, K. and Pitchumani, K. 2011. Copper(l)-catalyzed three component reaction of sulfonyl azide, alkyne, and nitrone cycloaddition/rearrangement cascades A novel one-step synthesis of imidazolidin-4-ones. Org. Lett. 13(21) 5728-5731. 

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