Photoredox CH arylation of heteroarenes by high-efficiency bismuth quantum dots

Pnictogen bismuth (Bi) has attracted great attention in recent years due to its unique properties. However, few reports have focused on the liquid-phase chemical transformation so far. In this work, zero-dimensional bismuth quantum dots (0D Bi QDs) are, for the first time, introduced as a heterogeneous photoredox catalyst for direct CH arylation of heteroarenes under ambient conditions. Due to high structural stability and superior catalytic property, the as-synthesized Bi QDs exhibited excellent direct CH arylation of heteroarenes in moderate to good yields at a very low loading (only 0.8 wt%) under visible light with simple protocol, amenable gram-scale synthesis and good reusability. Radical trapping experiments demonstrated that the aryl radicals generated on the surface of QDs. Density functional theory calculation demonstrates that the Bi QDs display suitable adsorption energy and efficient charge transfer to largely promote the direct CH arylation. Such a unique transformation opens up new opportunities toward direct CH arylation for valuable organic transformation.