Fig. 2

Substrate scope of oxidative [4 + 2] annulation of styrenes with alkynes. Reaction conditions: alkene 1 (0.26 mmol), alkyne 2 (0.2 mmol), Acr⁺-Mes ClO₄⁻ (3 mol%), Co(dmgH)₂py₂PF₆ (8 mol%) in DCE (14 mL), 3W blue LEDs, 24 h; isolated yields are shown. ^*0.2 mmol alkene and 0.6 mmol alkyne were used