Copper-Catalyzed [4+1+1] Annulation of Ammonium Salts and Anthranils: Synthesis of 2,3-Diaroylquinolines.

A copper(I)-catalyzed protocol is developed for the synthesis of various 2,3-diaroylquinolines starting from achiral ammonium salts and anthranils through [4+1+1] annulation. Using copper(I) chloride as the sole catalyst, this reaction is featured with easily available starting materials, broad substrate scope, good yields and simple reaction conditions.

Copper-Catalyzed Ring-Opening/Reconstruction of Anthranils with Oxo-Compounds: Synthesis of Quinoline Derivatives.

A copper-catalyzed protocol for the construction of various 2-aryl(alkyl)-3-acylquinolines or 3-arylquinolines using readily available anthranils and 1,3-diketones or aldehydes as starting materials is reported herein. Dioxygen as the sole oxidant and hexafluoroisopropanol as the solvent play an important role in both procedures. This ring-opening/reconstruction strategy involving N-O bond cleavage and C-N/C-C bond formation features high yields and broad substrate scope.

Copper-catalyzed coupling of anthranils and α-keto acids: direct synthesis of α-ketoamides.

Copper-catalyzed coupling of α-keto acids with anthranils is reported for the synthesis of α-ketoamides. This process involves N-O/C-O bond cleavages and C-N bond formation. Furthermore, the decarboxylation of α-keto acids can be successfully suppressed under redox-neutral conditions.

Transition-Metal-Free C-S Bond Formation: Synthesis of Polysubstituted Diaryl Sulfides and α-Thioarylcarbonyl Compounds.

A transition-metal-free protocol for the construction of C-S bonds has been developed. Acetylacetone acts as a new and green aryl source for the synthesis of polysubstituted diarylsulfides bearing a free hydroxy group and a ketone group, which provides a new access to a series of flavonoids containing a thioaryl group. In addition, a series of α-thioarylcarbonyl compounds are obtained in good to excellent yields.

Analysis of optical properties and response mechanism of H2S fluorescent probe based on rhodamine derivatives.

H2S plays a crucial role in numerous physiological and pathological processes. In this project, a new fluorescent probe, SG-H2S, for the detection of H2S, was developed by introducing the recognition group 2,4-dinitrophenyl ether. The combination of rhodamine derivatives can produce both colorimetric reactions and fluorescence reactions. Compared with the current H2S probes, the main advantages of SG-H2S are its wide pH range (5-9), fast response (30 min), and high selectivity in competitive species (including biological mercaptan). The probe SG-H2S has low cytotoxicity and has been successfully applied to imaging in MCF-7 cells, HeLa cells, and BALB/c nude mice. We hope that SG-H2S will provide a vital method for the field of biology.