Synlett 2007(15): 2410-2414  
DOI: 10.1055/s-2007-986627
LETTER
© Georg Thieme Verlag Stuttgart · New York

Suzuki-Miyaura Cross-Coupling of Arenediazonium Salts with Arylboronic Acids Catalyzed by a Recyclable Polymer-Supported N-Heterocyclic Carbene-Palladium Catalyst

Yuancheng Qin, Wei Wei, Meiming Luo*
Key Laboratory of Green Chemistry & Technology of Ministry of Education at Sichuan University, College of Chemistry, Sichuan University, Chengdu 610064, P. R. of China
Fax: +86(28)85462021; e-Mail: luomm@scu.edu.cn;
Further Information

Publication History

Received 13 March 2007
Publication Date:
23 August 2007 (online)

Abstract

The Suzuki-Miyaura cross-coupling of arenediazonium salts with arylboronic acids catalyzed by a recyclable polymer-supported N-heterocyclic carbene-Pd complex catalyst has been achieved for the first time. The reaction was performed at room ­temperature under aerobic conditions to give biaryls in good to ­excellent yields in the absence of a base. The supported catalyst could be reused several times and still retained its high activity.

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General Procedure for the Suzuki Cross-Couplings of Arenediazonium Tetrafluoroborate Salts and Arylboronic Acids Catalyzed by Polystyrene-Supported NHC-Pd Catalyst Polystyrene-supported NHC-Pd catalyst 1 (100 mg, 10 µmol Pd), arenediazonium tetrafluoroborate salt (0.5 mmol), and arylboronic acid (1 mmol) were mixed in EtOH (5 mL). The mixture was stirred at r.t. under aerobic conditions. When the reaction was complete, the catalyst was filtered and washed with Et2O (3 × 5 mL), and then dried under vacuum for the next run. The combined organic phase was dried over anhyd MgSO4, filtered, and evaporated under reduced pressure. The product was purified by silica gel column chromatography. The recycling experiments were carried out following the same procedure described above except using the recovered catalysts from the previous runs. All of the cross-coupling products are known and were identified by comparison of their NMR spectra and melting points with those reported in the literature.