Copper-catalyzed synthesis of aminoquinolines from ß-(2-aminophenyl)-α,ß-ynones using DMF as dual synthon.

A new and efficient method has been developed for the synthesis of 4-aminoquinoline through aerobic Cu(i)-catalyzed cyclization of ß-(2-aminophenyl)-α,ß-ynones. Under the optimized conditions, DMF could serve as a methine source to introduce C2 carbon and a nitrogen source to incorporate amino functionality in the 4th position. Mechanistic studies using 13C- and DMF-d7 revealed that the methine group was derived from a methyl substituent.

A copper(ii)-catalyzed annulative formylation of o-alkynylanilines with DMF: a single-step strategy for 3-formyl indoles.

In this paper, a copper(ii)-catalyzed reaction of o-alkynylanilines with dimethylformamide (DMF) in the presence of oxygen has been developed for synthesizing multisubstituted 3-formyl indole scaffolds. This one-pot reaction proceeds through a cascade 5-endo-dig cyclization followed by formylation to construct 1,2-disubstituted 3-formyl indoles. The key aspects of this synthesis method are the broad substrate scope (with 38 examples), and well tolerating various functional groups. In addition, a detailed mechanism has been proposed, where DMF may serve as a carbon source for the in situ C3 formylation of the obtained indole derivatives.