Ullmann-Type N -, S -, and O -Arylation Using a Well-Defined 7-Azaindole- N -oxide (7-AINO)-Based Copper(II) Catalyst: Scope and Application to Drug Synthesis.

An air-stable, robust, and well-defined copper(II)-7-azaindole- N -oxide-based catalyst [Cu 2 II (7-AINO) 4 ] (abbreviated as Cu(II)-7-AINO) has been demonstrated as an efficient catalyst for various Ullmann-type coupling reactions. This easily prepared and cost-effective catalyst facilitates the arylation and heteroarylation of diverse N -, S -, and O -nucleophiles, including azoles, aminoazoles, (hetero)arylthiols, and phenols. Notably, they also exhibit substantial compatibility with a wide range of functional groups. Furthermore, the catalyst demonstrates significant selectivity for -NH sites of aminoazoles and -SH sites of aminothiophenols over -NH 2 sites in both cases, enhancing its versatility. Exploiting the catalyst's chemo- and regioselective properties, we have successfully demonstrated the applicability of our methodology in synthesizing various drug molecules. Specifically, Epirizole analogue, Nilotinib, and Vortioxetine were successfully synthesized using our protocol.