N-Heterocyclic carbene-catalyzed tandem aza-benzoin/Michael reactions: on site reversal of the reactivity of N-Boc imines

A tandem NHC-catalyzed aza-benzoin/Michael reaction has been developed as a method to efficiently produce dihydroindenones and pyrrolidinone-containing tricycles. The novel reaction pattern involves tert-butyl aryl(tosyl)methylcarbamates reacting as both electrophile and nucleophile on the same carbon.