Fabrication of encapsulated and sticky surface-enhanced Raman spectroscopy substrate coupling with thin layer chromatography for determination of pesticide

Palladium catalyzed amidation of phenyl carboxylates and anilines using aqueous micellar catalysis

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Review of Thin-Layer Chromatography Tandem with Surface-Enhanced Raman Spectroscopy for Detection of Analytes in Mixture Samples

In the present work, quinoxaline-bridged bis(benzimidazolium) salts were prepared by the reaction of 2,3-bis(bromomethyl) quinoxaline and 1-substituted benzimidazole. The structures of the bis(benzimidazolium) salts were characterized by NMR, FT-IR, and elemental analysis techniques. Also, the photophysical properties of salts were investigated by UV–Vis absorption and fluorescence emission spectroscopy. Next, these quinoxaline bridged bis(benzimidazolium) salts were used as bidentate benzimidazol-2-ylidene ligand precursors in the palladium-catalyzed Suzuki-Miyaura and Mizoroki-Heck cross-couplings. These salts exhibited moderate-to-high activity in the palladium-catalyzed cross-coupling reactions. 

Applications of quinoxaline‐bridged bis(benzimidazolium) salts as ligand sources for the palladium‐catalyzed Suzuki and Heck cross‐coupling reactions in an aqueous medium

A modular and generic method for the Buchwald-Hartwig amination reactions of relatively unreactive aryl esters as acyl electrophiles and aryl chlorides as aryl electrophiles has been developed, leading to the efficient synthesis of amides/amines under air conditions and with low catalyst loadings. The success of this catalytic protocol is mainly attributed to the modification of the Pd-IPr skeleton with sterically hindered and electron-donating anisole groups. This method also features good functional group tolerance and excellent chemoselectivities. In summary, the results presented herein suggest the possibility of developing a versatile and general protocol for diverse electrophiles to undergo the Buchwald-Hartwig amination reactions, avoiding too much consideration of the reaction conditions for the substrate-dependent C-N bond formations.

Hong-Gang Xiong

Papers

Buchwald-Hartwig amination of aryl esters and chlorides catalyzed by the dianisole-decorated Pd-NHC complex.

Functional cotton fabric-based TLC-SERS matrix for rapid and sensitive detection of mixed dyes.