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Synlett 2011(4): 579-581  
DOI: 10.1055/s-0030-1259519
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

Palladium-Catalyzed Reaction of Olefins with PhI(OAc)2-TBAB System: An Efficient and Highly Selective Bisfunctionalization Strategy

Lei Yu*, Lingfeng Ren, Rong Yi, Yulan Wu, Tian Chen, Rong Guo
School of Chemistry and Chemical Engineering, Yangzhou University, Shouxihu Campus, Yangzhou 225002, P. R. of China
Fax: +86(514)87975244; e-Mail: yulei@yzu.edu.cn;
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Publikationsverlauf

Received 14 October 2010
Publikationsdatum:
27. Januar 2011 (online)

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Abstract

The palladium-catalyzed reaction of olefins with PhI(OAc)2-TBAB system provides a novel, efficient, and highly selective bisfunctionalization strategy to introduce bromo and oxygen groups simultaneously. The substituents on the C=C bond control the regioselectivity of this reaction, which could be an effective supplement of bromohydroxylation in organic synthesis.

Key words

bisfunctionalization reactions - olefins - palladium-catalyzed reactions - selective

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Yu L., Ren L.-F., Xu B., Guo R. Synth. Commun. 2010, 40, in press.

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Typical Procedure for the Preparation of 2 In the presence of Pd(OAc)2 (0.03 mmol, 6.7 mg), olefins (0.3 mmol), PhI(OAc)2 (0.6 mmol), and TBAB (0.3 mmol) were heated in MeCN (2 mL) at 60 ˚C. The reaction was monitored by TLC. When the reaction terminated, H2O (5 mL) was added, and the liquid was extracted by EtOAc (3 × 5 mL). The combined organic layer was dried by anhyd MgSO4, and the solvent was evaporated under vacuum. The residue was subjected to preparative TLC (eluent: PE-EtOAc = 8:1) to give the corresponding product 2.
Data for Compound 2a
Oil. IR (film): 2952, 1751, 1639, 1494, 1446, 1366, 1218, 1084, 1013, 986, 961, 904, 750, 706 cm-¹. ¹H NMR (600 MHz, CDCl3): δ = 7.52-7.53 (m, 4 H), 7.30-7.32 (m, 6 H), 3.28-3.30 (m, 2 H), 2.40-2.43 (m, 1 H), 2.25-2.28 (m, 2 H), 2.12 (s, 3 H), 1.83-1.85 (m, 1 H) ppm. ¹³C NMR (150 MHz, CDCl3): δ = 15.8, 22.3, 37.3, 74.4, 88.7, 127.0, 127.8, 129.7, 137.7, 168.0 ppm. MS (EI, 70 eV): m/z (%) = 278 (3) [M+ - Br], 183 (100). Anal. Calcd for C19H19BrO2: C, 63.52; H, 5.33. Found: C, 63.20; H, 5.14.

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Procedure for the Bromohydroxylation of Compound 1f
Compound 1f (0.3 mmol) and NBS (0.3 mmol) were stirred in acetone-H2O (2 mL; 5:1) at r.t. The reaction was monitored by TLC (eluent: PE). When the reaction terminated, the liquid was subjected to preparative TLC (eluent: PE-EtOAc = 7:1) to give the adduct 3 in 76% yield.
Data for 3 Oil. IR (film): 3060, 3029, 2971, 1493, 1448, 1425, 1332, 1279, 1226, 1163, 1062, 1032, 993, 913, 843, 750, 699 cm-¹. ¹H NMR (600 MHz, CDCl3): δ = 7.25-7.43 (m, 10 H), 4.09 (s, 2 H), 3.14 (s, 1 H) ppm. ¹³C NMR (150 MHz, CDCl3): δ = 44.0, 76.9, 126.4, 127.7, 128.4, 143.5. MS (EI, 70 eV): m/z (%) = 276 (3) [M+], 105 (100). Anal. Calcd for C14H13BrO: C, 60.67; H, 4.73. Found: C, 60.95; H, 4.88.