Transition-Metal-Free Quinoline Synthesis from Acetophenones and Anthranils via Sequential One-Carbon Homologation/Conjugate Addition/Annulation Cascade.

A transition-metal-free method for the construction of functionalized quinolines from readily available acetophenones and anthranils is reported. This one-pot reaction cascade involves in situ generation of α,β-unsaturated ketones from the acetophenone via one-carbon homologation by DMSO followed by the aza-Michael addition of anthranils and subsequent annulation. DMSO acted in this reaction not only as solvent but also as one carbon source, thus providing a highly atom-economical and environmentally benign approach for the synthesis of 3-substituted quinolines.