A facile and efficient one-pot procedure for the preparation of indeno[1,2-b]indole derivatives via three-component domino reaction of ninhydrin, enaminones, and malononitrile catalyzed by L-proline is described. In this reaction, two rings and four bonds were formed by one-pot.

A mild and efficient synthesis of 2-arylindazole derivatives via the reductive cyclization of nitro-aryl substrates mediated by a low-valent titanium reagent (TiCl₄/Sm/Et₃N) has been developed. The attractive features of the current method include an N–N bond formation and the selective reduction of the C = N bond and nitro group, both of which were easily achieved in one-pot by controlling the pH of the reaction mixture.

A improved and efficient procedure for the synthesis of pyrrolo[2,3,4-kl]acridin-1-one derivatives via the reaction of isatin and enaminone catalyzed by ceric ammonium nitrate under ultrasonic condition has been developed. Compared with the conventional methods, the remarkable advantages of this method are mild reaction conditions, operational simplicity, higher yield, and shorter reaction times.

A simple and efficient synthesis of pyrrolo[2,3,4-kl]acridine-1-one derivatives via the cascade reaction of isatins with enaminones catalyzed by silica sulfuric acid (SSA) has been established. In this reactions, SSA shows a highly catalytic nature: easy to handle procedure, short reaction time, recycle exploitation, insensitivity to air and moisture, and excellent isolated yields. The catalyst could be recycled at least five times.

A series of chromeno[4,3-d]pyrazolo[3,4-b]pyridin-6(3H)-one derivatives was easily and efficiently synthesized by the reaction of 2H-chromen-2-ones with pyrazol-5-amines catalyzed by CuCl₂⋅2H₂O in ethanol. This protocol has the advantages of mild reaction conditions, easy work-up, and high yields. These compounds were showed to have high fluorescence quantum yields, which mentioned their value as luminescence or fluorescence probe.

New crown ether carrying two fluorionophores of cis-dibenzothiazolyldibenzo-24-crown-8 was synthesized from cis-diformyldibenzo-24-crown-8 and 2-aminobenzenethiol. The binding behavior and the optical properties of the crown ether were examined through UV-visible spectroscopy and fluorescence spectroscopy. When complexed with Na⁺, K⁺, Rb⁺, and Cs⁺ ions, it led to intramolecular charge transfer and caused the changes of the fluorescence spectra. The protonation of the crown ether was also studied. With protonation using CF₃COOH, the absorption bands and the fluorescence spectroscopy changed, the maximal fluorescence wavelengths red shifted and the fluorescence intensity with the maximum at 433 nm enhanced strongly. J. Heterocyclic Chem., (2011).

A new crown ether of 2,13-dibenzothiazol-2′-yldibenzo[b,k]-18-crown-6 was synthesized from 2,13-diformyl- dibenzo[b,k]-18-crown-6 with 2-aminothiophenol. The binding behavior and the optical properties of the crown ether were examined through UV-visible spectroscopy and fluorescence spectroscopy. When complexed with Na⁺, K⁺, Rb⁺ and Cs⁺ ions, it led to intramolecular charge transfer and caused the changes of the fluorescence spectra. The protonation of the crown ether was also studied.