Synthesis of biaryls by chitosan-2-thiophenecarbaldhyde supported palladium complex under air conditions

Palladium catalyzed carbon-carbon bond-forming reactions have played a crucial role in synthetic organic chemistry. Heterogeneous catalyst in the Suzuki-Miyaura coupling of arylboronic acids and aryl halides represent as the most successful methods for the preparation of biaryls.1 This reaction have shown to have widespread applications in the synthesis of natural products, biologically active molecules, and materials science.2 Recently, polymers3 especially biodegradable polymers4 are used in the synthesis of heterogeneous catalysts. Herein, we have reported an environmental magnetic chitosan-2-thiophenecarbaldhyde based palladium complex (Fe@CS-TCp-Pd), which was efficiently used as a heterogeneous catalyst for Suzuki-Miyaura cross-coupling reactions in aqueous media under air condition. The catalyst shows not only high catalytic activity, but also offers many practical advantages such as thermal stability, and recyclability. The catalyst was reused for seven consecutive runs in Suzuki-Miyaura reaction with consistent activity. The excellent catalytic performance in aqueous media and the easy separation of the catalyst make it a good heterogeneous system and a useful alternative to other heterogeneous palladium catalysts. All the products were characterized by IR, 1H, and 13C NMR spectroscopy.

کلیدواژه ها:

Cross-coupling reaction ، Palladium complex ، Suzuki reaction ، Chitosan ، Thiophenecarbaldhyde.