Cesium lead halide perovskite (CsPbX3, X = Cl, Br, and I) nanocrystals (NCs) have attracted enormous attention because of their great potential for optoelectronic applications, such as light-emitting diodes (LEDs). However, the photoluminescence and surface ligands of CsPbX3 NCs have a great impact on their device applications. Herein, we report a molecular superacid of bis­(trifluoromethane)­sulfonimide (TFSI), which could boost the photoluminescence in the metal halide perovskite nanocrystals. In particular, the photoluminescence quantum yield (PLQY) of CsPbI3 nanocrystals could be greatly improved from 28.6% to near 100% with the superacid treatment. The improved PLQY in CsPbX3 nanocrystals is mainly contributed from the surface passivation based on the characterizations. The CsPbX3 nanocrystals were further modified with PMMA, which could greatly improve their stability while preserving high photoluminescence and good dispersion. The use of superacid combined with a polymer for improving the photoluminescence and stability in CsPbX3 provides an alternative strategy for optoelectronics.

An efficient method for the synthesis of furo[3,2‐c]coumarins through FeCl3 or ZnCl2‐mediated multicomponent tandem reactions in the presence of arylglyoxal monohydrates, 4‐hydroxycoumarin, and allyltrimethylsilane in toluene is reported. This reaction involves the formation of two C‐C bonds and one C‐O bond. This process provided the privileged structures of furo[3,2‐c]coumarins in moderate to good yields under mild conditions. Notable features of the procedure such as easily accessible starting materials, good functional group tolerance, and high atom economy have been developed.

A concise, one-pot route for the synthesis of furo[3,2-c]coumarins under the catalysis of Zn(OTf) 2 is reported. Utilizing this synthetic strategy, libraries of furocoumarin analogues can be easily obtained by multicomponent tandem reactions with different nucleophile in the presence of 4-hydroxycoumarin and arylglyoxal monohydrate system, This transformation exhibited highly atom economical and good functional group compatibility.

An efficient method for the facile synthesis of benzofurans through FeCl3‐mediated intermolecular tandem reaction of anisole with glyoxal monohydrates was reported. This process provided the privileged structures of benzofurans in moderate to good yields under mild conditions. This reaction has many advantages, such as readily available starting materials, high atom economy and good functional group tolerance. This is firstly reported that FeCl3, acting as both a Lewis acid and an oxidant, was used for the synthesis of benzofuran.

Synthesis of a variety of aryldifluoromethylated coumarins by cascade radical cyclization reactions in systems where alkynoates and α,α-difluoroarylacetic acids coexist, using (NH4)2S2O8 as oxidant and CuI as catalyst. The transformation was accomplished under mild conditions.