Synlett 2012(2): 259-262  
DOI: 10.1055/s-0031-1290078
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

Pd(II)-Catalyzed Direct Olefination of Arenes with Allylic Esters and Ethers

Xiaojie Shang, Yun Xiong, Yuexia Zhang, Lei Zhang, Zhongquan Liu*
State Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University, Lanzhou, Gansu 730000, P. R. of China
Fax: +86(931)8915557; e-Mail: liuzhq@lzu.edu.cn;
Further Information

Publication History

Received 25 September 2011
Publication Date:
03 January 2012 (online)

Abstract

A convenient Pd(II)-catalyzed direct olefination of unactivated arenes with allylic esters and ethers via C-H activation was demonstrated. Under the typical conditions, various aryl-substituted allylic esters and ethers can be prepared.

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The cinnamyl acetate was also generated in the absence of toluene when PdCl2(Ph3P)2 was used as catalyst.

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Typical Procedure A mixture of mesitylene (1.9 mL, as solvent), allyl acetate (0.6 mmol, 60 mg), Pd(OAc)2 (0.06 mmol), AgOAc (1.2 mmol), and DMSO (0.1 mL) was added to a round-bottom flask. After stirring for 12 h at 110 ˚C, the solvent was removed under reduced pressure, and the residue was purified by flash chromatography on silica gel (eluent: PE-EtOAc = 20:1) to afford (E)-3-mesitylallyl acetate (73 mg, 56%) as a colorless oil. ¹H NMR (400 MHz, CDCl3): δ = 6.88 (s, 2 H), 6.64 (d, J = 16.0 Hz, 1 H), 5.84-5.76 (m, J = 16.0, 6.4 Hz, 1 H), 4.76 (dd, J = 6.4, 1.2 Hz, 2 H), 2.28 (s, 9 H), 2.12 (s, 3 H). ¹³C NMR (100 MHz, CDCl3): δ = 170.8, 136.4, 135.8, 132.9, 131.9, 128.6, 128.5, 65.4, 21.0, 20.9, 20.8, 20.7. HRMS: m/z calcd for C14H18NaO2: 241.1199; found: 241.1197.