tert-Butyl nitrite mediated regiospecific nitration of (E)-azoarenes through palladium-catalyzed directed C-H activation.

An efficient protocol for the Pd-catalyzed regiospecific ortho-nitration of (E)-azoarenes has been achieved for the first time using tBuONO as a nitrating agent under atmospheric oxygen. A series of both symmetrical and unsymmetrical azoarenes were nitrated efficiently by this procedure providing excellent chemo- and regioselectivity and compatibility with a broad array of functional groups.