Divergent Syntheses of Isoquinolines and Indolo[1,2‑a]quinazolines by Copper-Catalyzed Cascade Annulation from 2‑Haloaryloxime Acetates with Active Methylene Compounds and Indoles

A convenient and reliable method for the direct construction of isoquinolines is described. A series of isoquinoline derivatives were synthesized, with high chemo- and regioselectivities, via the copper-catalyzed cascade reaction of 2-haloaryloxime acetates with β-diketones, β-keto esters, and β-keto nitriles. This tandem annulation process features inexpensive catalysts, no need for additional ligands, and excellent functional group tolerance, which makes it have potential synthetic applications. Furthermore, this strategy could also be used to enter functionalized indolo­[1,2-a]­quinazolines by using indoles as the counterpart of the 2-haloaryloxime acetates.