Rh(III)-Catalyzed C-H Amidation of 2-Arylindoles with Dioxazolones: A Route to Indolo[1,2-c]quinazolines.

Rhodium(III)-catalyzed C-H amidation of 2-arylindoles with dioxazolones for the synthesis of indolo[1,2-c]quinazolines is reported. The reaction is compatible with a wide range of electronically diverse 2-arylindoles and dioxazolones, providing indolo[1,2-c]quinazolines in high to excellent yields. Most notably, the combination of this Rh-catalyzed C-H amidation and intramolecular N-H/N-C(O) cyclization enables the most straightforward direct route to indolo[1,2-c]quinazolines to date. Mechanistic studies and evaluation of antitumor activity of these high value heterocycles are disclosed.