Copper-Catalyzed Oxidative Dehydrogenative Reaction of Quinoline-N-Oxides with Donor-Acceptor Cyclopropanes: Installation of a Tertiary Alkyl Motif at C2 Position.

A copper-catalyzed oxidative dehydrogenative reaction of quinoline N-oxides with donor-acceptor cyclopropanes has been demonstrated to construct C2-alkylated quinolines containing a γ-keto diester motif. The use of molecular oxygen as an oxidant, excellent site-selectivity, and good functional group tolerance are the important features in this process. The preliminary mechanistic studies demonstrate that the catalyst plays a dual role as a Lewis acid and a redox catalyst.