Rh(iii)-catalyzed spiroannulation of 3-arylquinoxalin-2(1 H )-ones with alkynes: practical access to spiroquinoxalinones.

The Rh(iii)-catalyzed synthesis of spiroquinoxalinone derivatives from 3-arylquinoxalin-2(1 H )-ones and alkynes via a C-H functionalization/[3 + 2] annulation sequence has been developed. This method, featuring low catalyst loading, was amenable to Gram scale synthesis and tolerated a variety of functional groups and substitution patterns on the aryl rings, providing the target products in good to excellent yields.