Sustainable synthetic methods: domino construction of dihydropyridin-4-ones and beta-amino esters in aqueous ethanol.

Domino reactions were designed to allow the byproduct of an upstream reaction to be internally recycled to catalyze a downstream reaction in a one-pot tandem sequence. Nitroarene reduction by In(0) generates an amine and In (III) byproducts. Addition of aldehyde followed by Danishefsky's diene or silyl ketene acetal provides access to dihydropyridin-4-ones or beta-amino esters, respectively, in yields that are comparable or superior to the reported stepwise reactions.