CsPbBr3 perovskite quantum dots as a visible light photocatalyst for cyclisation of diamines and amino alcohols: an efficient approach to synthesize imidazolidines, fused-imidazolidines and oxazolidines

Abstract

We report the synthesis of highly stable CsPbBr₃QD based photocatalysts using dibromoisocyanuric acid (DBI) as a benign non-toxic bromide precursor. The QDs were applied as a visible light photocatalyst for intramolecular cyclisation of diamines and amino alcohols to obtain a range of enantiopure bioactive heterocycles such as imidazolidines, fused-imidazolidines and 1,3-oxazolidines in high yields (isolated yield up to 82%, ee >99%). The reaction is simple and operates in open air at room temperature and is scalable. The QDs exhibited a high TON (177) and catalytic efficiency (the rate was three times faster compared to conventionally prepared CsPbBr₃QDs). The apparent quantum efficiency (AQE) of the reaction was close to unity (ϕ = 0.96 at 460 nm and ϕ = 0.98 at 436 nm).