Triple Nucleophilic Attack of Nitromethane on (2-Iminoaryl)divinyl Ketones: A Domino Synthetic Strategy for Hexahydrophenanthridinones

A novel
domino reaction of (2-iminoaryl)­divinyl ketones with nitromethane
was developed for the efficient synthesis of hexahydrophenanthridin-9­(5H)-ones. The reaction proceeded smoothly from readily available
starting materials under mild reaction conditions to construct three
new bonds and two rings with high diastereoselectivities in good to
excellent yields in a single step. A mechanism is proposed, involving
a stepwise double Michael addition/aza-Henry reaction cascade, and
in this transformation, nitromethane acts as a trinucleophile.