Sustainable Suzuki-Miyaura Reaction Catalyzed by Pd(OAc)₂ Immobilized on Reversed-Phase Alumina

Abstract

Employing Pd(OAc)₂ immobilized on amorphous N,N-diethylaminopropyl alumina, Suzuki-Miyaura coupling of aryl halide with arylboronic acid was realized in 50% aqueous ethanol at room temperature, which enabled repeated use up to four times in 96% average yield and achieved a turnover number of 15 000.

arylations - boron - cross-coupling - heterogeneous catalysis - palladium - supported catalysis

References and Notes

1a Recent reviews: Miyaura N. Suzuki A. Chem. Rev.  1995,  95:  2457 

1b Hassan J. Sévignon M. Gozzi C. Schulz E. Lemaire M. Chem. Rev.  2002,  102:  1359 

1c Miyaura N. Top. Curr. Chem.  2002,  219:  11 

1d Kotha S. Lahiri K. Kashinath D. Tetrahedron  2002,  58:  9633 

1e Littke AF. Fu GC. Angew. Chem. Int. Ed.  2002,  41:  4176 

2 Rouhi AM. Chem. Eng. News  2004,  82 (36):  49 

3a Shimizu K.-I. Koizumi S. Hatamachi T. Yoshida H. Komai S. Kodama T. Kitayama Y. J. Catal.  2004,  228:  141 

3b Crudden CM. Sateesh M. Lewis R. J. Am. Chem. Soc.  2005,  127:  10045 

4 Kudo D. Masui Y. Onaka M. Chem. Lett.  2007,  36:  918 

For our representative efforts in this area, see:

5a Hagiwara H. Inotsume S. Fukushima M. Hoshi T. Suzuki T. Chem. Lett.  2006,  35:  926 

5b Hagiwara H. Isobe K. Numamae A. Hoshi T. Suzuki T. Synlett  2006,  1601 

5c Hagiwara H. Numamae A. Isobe K. Hoshi T. Suzuki T. Heterocycles  2006,  68:  889 ; and earlier references cited therein

For some selected Suzuki-Miyaura reactions in aqueous alcohol, see:

6a Marck G. Villiger A. Buchecker R. Tetrahedron Lett.  1994,  35:  3277 

6b Liu L. Zhang Y. Xin B. J. Org. Chem.  2006,  71:  3994 

6c Zhang G. Synthesis  2005,  537 

6d Arvela RK. Leadbeater NE. Collins MJ. Tetrahedron  2005,  61:  9349 

6e Chanthavong F. Leadbeater NE. Tetrahedron Lett.  2006,  47:  1909 

6f Hagiwara H. Ko KH. Hoshi T. Suzuki T. Chem. Commun.  2007,  2838 

7

Typical Experimental Procedure: To a stirred solution of 4-bromoacetophenone (96 mg, 0.48 mmol), 4-acetylphen-ylboronic acid (110 mg, 0.67 mmol), and K₂CO₃ (141 mg, 1 mmol) in EtOH (1 mL) and H₂O (1 mL) was added NDEAP-Al₂O₃-Pd(OAc)₂ (256 mg, Pd loading: 0.1 mmol/g alumina, 0.026 mmol). After stirring for 5 min, the product was triturated with EtOAc several times. The combined organic layer was evaporated to dryness and the residue was purified by column chromatography (CH₂Cl₂-n-hexane, 3:10) to provide a biaryl product (121 mg, 100%).

8 Arvela RK. Leadbeater NE. Sangi MS. Williams VA. Granados P. Singer RD. J. Org. Chem.  2005,  70:  161