Base-free conjugate addition of aliphatic nitro compounds to enones in BmimNTf2: a recyclable synthesis of γ-nitro ketones

A base-free, recyclable approach for the conjugate addition of aliphatic nitro compounds to enones to give γ-nitro ketones is presented. Reactions are carried out in an ionic liquid with a basic anionic moiety, such as BmimNTf2, as the solvent, under mild conditions (25 °C for 24 h). The IL medium could be recycled several times without any appreciable loss of activity, after a simple extraction procedure for the separation of the reaction product.