Fig. 8: Comparison of selected photocatalysts.
From: Alkyne–Alkene [2 + 2] cycloaddition based on visible light photocatalysis

Reactions were performed with 0.025 mmol scale under Ar. Yields determined by 1H NMR spectroscopic analysis against an internal standard. (1,1,2-trichloroethene). a Green LED was used instead of blue LED.