RuCl₃-Catalyzed Regioselective Diarylation with Aryl Tosylates via C-H Activation

Abstract

The direct arylation of arylpyridines with aryl tosylates was carried out smoothly in the presence of 2.5 mol% RuCl₃ using MesCOOH as crucial promoter to generate biarylated products. The method is simple, efficient, safe, and regioselective, can be performed in the absence of expensive ligands, and does not require any precautions with regard to the exclusion of air and moisture. The biarylated products were obtained in good yields.

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GRAPHICAL ABSTRACT

Keywords:

• Aryl tosylates
• C-H activation
• diarylation
• ruthenium catalysis

ACKNOWLEDGMENT

This study was supported by the Science Technology Department of Zhejiang Province (Grant No. 2010-R-50014-15).

Notes

^a Reaction conditions: 2-phenylpyridine (1 mmol), 4-methylbenzenesulfonate (2.2 mmol), catalyst (2.5 mol%), MesCOOH (1 mmol), K₂CO₃ (2 mmol), NMP (5 mL), 140 °C, 12 h.

^b Isolated yields.

^a Reaction conditions: 2-phenylpyridine (1 mmol), 4-methylbenzenesulfonate (2.2 mmol), RuCl₃ (2.5 mol%), acid (1 mmol), K₂CO₃ (2 mmol), NMP (5 mL), 140 °C, 12 h.

^b Isolated yields.

^a Reaction conditions: 2-phenylpyridine (1 mmol), 4-methylbenzenesulfonate (2.2 mmol), RuCl₃ (2.5 mol%), MesCOOH (1 mmol), base (2 mmol), NMP (5 mL), 140 °C, 12 h.

^b Isolated yields.

^a Reaction conditions: substrate (1 mmol), aryl tosylates (2.2 mmol), RuCl₃ (2.5 mol%), MesCOOH (1 mmol), K₂CO₃ (2 mmol), NMP (5 mL), 140 °C, 12 h.

^b Isolated yields.

^c Monoarylated product was isolated in 37% yield.