Ni-catalyzed hydroarylation of alkynes with unactivated β-C(sp 2 )-H bonds.

Hydroarylation of alkynes with unactivated C(sp 2 )-H bonds via chelated C-H metalation mainly occurs at γ-position to the coordinating atom of directing groups via stable 5-membered metallacycles, while β-C(sp 2 )-H bond-involved hydroarylation has been a formidable challenge. Herein, we used a phosphine oxide-ligated Ni-Al bimetallic catalyst to enable β-C-H bond-involved hydroarylations of alkynes via a rare 7-membered nickelacycle.