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Synlett 2011(11): 1626-1630  
DOI: 10.1055/s-0030-1260789
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

Copper-Catalyzed Arylation of Arylboronic Acids with Aldehydes

Hanmei Zhenga, Jinchang Dinga,b, Jiuxi Chen*a, Miaochang Liua, Wenxia Gaoa, Huayue Wu*a
a College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, P. R. of China
Fax: +86(577)88368280; e-Mail: jiuxichen@wzu.edu.cn; e-Mail: huayuewu@wzu.edu.cn;
b Wenzhou Vocational & Technical College, Wenzhou 325035, P. R. of China
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Publikationsverlauf

Received 1 February 2011
Publikationsdatum:
15. Juni 2011 (online)

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Abstract

A novel copper-catalyzed arylation of arylboronic acids with aldehydes under oxygen atmosphere was achieved in the presence of Cu(OTf)2 and Xantphos, affording diaryl ketone derivatives in moderate to good yields. The efficiency of this reaction was demonstrated by the compatibility with fluoro, bromo, chloro, nitro, ­methylsulfonyl, and trifluoromethyl groups.

Key words

arylation - diaryl ketones - copper - catalysis

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General Procedure for the Synthesis of Diaryl Ketones Under nitrogen atmosphere, a Schlenk tube was charged with aldehyde (0.3 mmol), arylboronic acid (0.6 mmol), Cu(OTf)2 (10 mol%), Xantphos ligand (15 mol%), and KF˙2H2O (0.6 mmol) in toluene (2 mL) under ice-salt
(-20 ˚C). The mixture was stirred for 6 h at r.t. under nitrogen atmosphere. Then pass into the oxygen, the mixture was stirred for 0.5 h at r.t. and heated up to reflux temperature (about 120 ˚C) for 24 h under oxygen atmosphere. After the completion of the reaction, as monitored by TLC, the solvent was concentrated in vacuo, and the residue was purified by flash column chromatog-raphy on silica gel (300-400 mesh) with PE-EtOAc as eluent to give the desired product.
Naphthalen-2-yl(4-nitrophenyl)methanone (3ai, Table 3, Entry 9)
¹H NMR (300 MHz, CDCl3): δ = 7.57-7.69 (m, 2 H), 7.91-8.00 (m, 6 H), 8.23 (s, 1 H), 8.22-8.40 (m, 2 H). ¹³C NMR (125 MHz, CDCl3): δ = 123.6, 125.2, 127.2, 127.9, 128.8, 129.0, 129.5, 130.7, 132.1, 132.4, 133.5, 135.6, 143.2, 149.8, 194.8. ESI-MS: m/z (%) = 278 (100) [M + 1]+. Anal. Calcd for C17H11NO3: C, 73.64; H, 4.00. Found: C, 73.66; H, 4.05.
4-Methylsulfonylphenyl(4-tolyl)methanone (3db, Table 3, Entry 12)
¹H NMR (300 MHz, CDCl3): δ = (s, 3 H), 3.12 (s, 3 H), 7.32 (d, J = 8.1 Hz, 2 H), 7.71 (d, J = 8.1 Hz, 2 H), 7.93 (d, J = 8.4 Hz, 2 H), 8.06 (d, J = 8.4 Hz, 2 H). ¹³C NMR (125 MHz, CDCl3): δ = 21.7, 44.4, 127.4, 129.3, 130.3, 133.7, 142.7, 143.2, 144.5, 194.8. ESI-MS: m/z (%) = 275 (100) [M + 1]+. Anal. Calcd for C15H14O3S: C, 65.67; H, 5.14. Found: C, 65.82; H, 5.22.
2,6-Dinitrophenyl(4-tolyl)methanone (3hb, Table 3, Entry 16)
¹H NMR (300 MHz, CDCl3): δ = (s, 3 H), 7.29 (d, J = 8.1 Hz, 2 H), 7.63 (d, J = 8.1 Hz, 2 H), 7.70 (d, J = 8.1 Hz, 2 H), 8.62 (d, J = 8.1 Hz, 2 H), 9.08 (s, 1 H). ¹³C NMR (125 MHz, CDCl3): δ = 21.8, 120.1, 128.4, 129.6, 129.8, 130.3, 132.4, 141.7, 146.0, 146.0, 148.4, 190.9. MS (EI): m/z (%) = 287 (100) [M + 1]+. Anal. Calcd for C14H10N2O5: C, 58.74; H, 3.52. Found: C, 58.83; H, 3.63.