Reactivity of secondary $N$-alkyl acrylamides in Morita–Baylis–Hillman reactions

Abstract

The Morita–Baylis–Hillman (MBH) reaction of secondary $N$-alkyl acrylamides, discarded up to now from investigations of the scope of activated alkenes, was studied. Optimization of the reaction conditions revealed that a balance must be found between activation of the MBH coupling reaction and that of the undesired competitive aldehyde Cannizzaro reaction. Using 3-Hydroxyquinuclidine (3-HQD) in a $1{:}1$ water-2-MeTHF mixture provides the appropriate conditions that were applicable to a wide range of diversely substituted secondary $N$-alkyl acrylamides and aromatic aldehydes, giving rise to novel amide-containing MBH adducts under mild and clean conditions.

Keywords

• Morita–Baylis–Hillman
• Acrylamides
• Aqueous solvents
• Biobased solvents
• Furfural
• HMF