Download PDF
Synlett 2012; 23(8): 1257-1261
DOI: 10.1055/s-0031-1290938
letter
© Georg Thieme Verlag Stuttgart · New York

Discovery of A Novel Palladium Catalyst for the Preparation of Enynes with a Copper- and Ligand-Free Sonogashira Reaction

Xia Mi
Chemistry Department, Henan Key Laboratory of Chemical Biology and Organic Chemistry, Key Laboratory of Applied Chemistry of Henan Universities, Zhengzhou University, Zhengzhou 450052, P. R. of China, Fax: +86(371)67979408   Email: wyj@zzu.edu.cn   Email: hmm@zzu.edu.cn
,
Mengmeng Huang*
Chemistry Department, Henan Key Laboratory of Chemical Biology and Organic Chemistry, Key Laboratory of Applied Chemistry of Henan Universities, Zhengzhou University, Zhengzhou 450052, P. R. of China, Fax: +86(371)67979408   Email: wyj@zzu.edu.cn   Email: hmm@zzu.edu.cn
,
Yujian Feng
Chemistry Department, Henan Key Laboratory of Chemical Biology and Organic Chemistry, Key Laboratory of Applied Chemistry of Henan Universities, Zhengzhou University, Zhengzhou 450052, P. R. of China, Fax: +86(371)67979408   Email: wyj@zzu.edu.cn   Email: hmm@zzu.edu.cn
,
Yangjie Wu*
Chemistry Department, Henan Key Laboratory of Chemical Biology and Organic Chemistry, Key Laboratory of Applied Chemistry of Henan Universities, Zhengzhou University, Zhengzhou 450052, P. R. of China, Fax: +86(371)67979408   Email: wyj@zzu.edu.cn   Email: hmm@zzu.edu.cn
› Author Affiliations
Further Information

Publication History

Received: 01 January 2012

Accepted after revision: 17 March 2012

Publication Date:
26 April 2012 (online)

    Permissions and Reprints All articles of this category


Abstract

A new palladium(II) complex based on N,N-dimethylethanolamine, (SP-4-1′)-bis[N,N-dimethylaminoethoxy-kN,O]palladium(II) which coordinates with two moles of AcOH, has been synthesized. The structure of the complex has been established by X-ray diffraction analysis. Using this complex as a catalyst, a series of conjugated enynes were successfully synthesized by Sonogashira cross-coupling reaction in the absence of co-catalyst CuX and any ligand at room temperature during 20 hours affording the corresponding products in moderate to excellent yields. The optimized catalytic systems are tolerant in the presence of a broad variety of functional groups in the substrates. The catalytic system was found to be ineffective for vinyl chloride. Moreover, it was found that (Z)-β-bromostyrene reacts with terminal alkynes with retention of the steric configuration and the transformation of most of the Z-isomer did not occur in this reaction.

Key words

N,N-dimethylethanolamine - copper-free - ligand-free - Sonogashira reaction - enyne - β-bromostyrene - stereochemistry

Supporting Information

    for this article is available online at http://www.thieme-connect.com/ejournals/toc/synlett.
  • Supporting Information
 

  • References

    • 1a Doucet H, Hierso JC. Angew. Chem. Int. Ed. 2007; 46: 834
    • 1b Chinchilla R, Nájera C. Chem. Rev. 2007; 107: 874
    • 2a Liu RR, Zhang JL. Adv. Synth. Catal. 2011; 353: 36
      Crossref
    • 2b Jiang H, Gschwend B, Albrecht Ł, Hansen SG, Jorgensen KA. Chem. Eur. J. 2011; 17: 9032
      Crossref
    • 2c Chen JL, Zheng F, Huang YG, Qing FL. J. Org. Chem. 2011; 76: 6525
      Crossref
  • 3 Mohamed YM. A, Hansen TV. Tetrahedron Lett. 2011; 52: 1057
    Crossref
    • 4a Trost BM. Angew. Chem. Int. Ed. 1995; 34: 259
      Crossref
    • 4b Wakatsuki Y. J. Organomet. Chem. 2004; 689: 4092
      Crossref
  • 5 Evans DA, Burch JD. Org. Lett. 2001; 3: 503
    CrossrefPubMed
  • 6 Siemens P, Livingston RC, Diederich F. Angew. Chem. Int. Ed. 2000; 39: 2632
    Crossref
  • 7 Vechorkin O, Barmaz D, Proust V, Hu X. J. Am. Chem. Soc. 2009; 131: 12078
    CrossrefPubMed
  • 8 Okuro K, Furuune M, Enna M, Miura M, Nomura M. J. Org. Chem. 1993; 58: 4716
  • 9 Guo SM, Deng CL, Li JH. Chin. Chem. Lett. 2007; 18: 13
    Crossref
    • 10a Lauterbach T, Livendahl M, Rosellon A, Espinet P, Echavarren AM. Org. Lett. 2010; 12: 3006
      CrossrefPubMed
    • 10b Sawant DN, Tambade PJ, Wagh YS, Bhanage BM. Tetrahedron Lett. 2010; 51: 2758
      Crossref
    • 10c Negishi E, Shi J, Zeng XZ. Tetrahedron 2005; 61: 9886
      Crossref
  • 11 Gülcemal S, Kani I, Yilmaz F, Çetinkaya B. Tetrahedron 2010; 66: 5602
    Crossref
  • 12 Huang MM, Feng YJ, Wu YJ. Tetrahedron 2012; 68: 376
    Crossref
  • 13 CCDC 869934 contains the supplementary crystallographic data of compound 2 for this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Center via http://www.ccdc.cam.ac.uk/data_request/cif
  • 14 Kim SH, Wei HX, Willis S, Li G. Synth. Commun. 1999; 29: 4179
    Crossref
  • 15 Donovan PM, Scott LT. J. Am. Chem. Soc. 2004; 126: 3108
    Crossref
  • 16 CCDC 869935 contains the supplementary crystallographic data of compound 7 for this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Center via http://www.ccdc.cam.ac.uk/data_request/cif
  • 17 Synthesis of (Me2NCH2CH2O)2Pd⋅2AcOH: A solution of Me2NCH2CH2OH (0.24 g, 2.68 mmol) in toluene (10 mL) was add to a stirred solution of Pd(OAc)2 (0.3 g, 1.34 mmol) in toluene (10 mL), and the mixture was stirred at r.t. After 2 d all volatiles were removed under reduced pressure to give 2 as a yellow crystalline solid. Yield: 0.54 g (80%); mp 93–95 °C. 1H NMR (400 MHz, C6D6): δ = 1.92–2.00 (m, 4 H, CH2N), 2.01 (s, 6 H, CH 3COOH), 2.17 (s, 12 H, CH3N), 3.37–3.75 (m, 4 H, CH2O), 11.00–11.15 (br s, 2 H, CH3COOH). 13C NMR (100 MHz, C6H6): δ = 22.08 (CH3COOH), 49.63 (CH3N), 63.87 (CH2N), 68.50 (CH2O), 174.27 (C=O). Anal. Calcd for C8H20N2O2Pd⋅2AcOH: C, 35.78; H, 7.01; N, 6.96. Found: C, 35.20; H, 6.79; N, 6.88
  • 18 Palladium-Catalyzed Sonogashira Reaction of β-Bromostyrene and Terminal Acetylene (Table 1 and Table 2): Table 2, entry 2, is given as an example: β-Bromostyrene (183 mg, 1.0 mmol), p-tolyacetylene (174 mg, 1.5 mmol), alkoxypalladium complex (4 mg, 1 mol%), Cs2CO3 (652 mg, 2.0 mmol) and DMF (2 mL) were added in Schlenk flask under nitrogen atmosphere. The reaction mixture was stirred at r.t. for 20 h. Then H2O (50 mL) was added and the resulting mixture was extracted with CH2Cl2 (3 × 20 mL). The combined organic layer was dried over anhyd Na2SO4. After filtration, the solvent was removed under reduced pressure. The residue was purified by TLC using petroleum ether as an eluent to give the pure diphenyl acetylene. Yield: 93%; white solid; mp 75–76 °C (lit.19 75–76 °C). For E-isomer: 1H NMR (400 MHz, CDCl3): δ = 2.38 (s, 3 H, Me), 6.41 (d, J = 16.1 Hz, 1 H, CH=), 7.04 (d, J = 16.1 Hz, 1 H, CH=), 7.16 (d, J = 7.8 Hz, 2 H), 7.29–7.46 (2 × m, 7 H, ArH). For Z-isomer: 1H NMR (400 MHz, CDCl3): δ = 2.39 (s, 3 H, Me), 5.93 (d, J = 12.2 Hz, 1 H, CH=), 6.70 (d, J = 11.7 Hz, 1 H, CH=), 7.29–7.46 (2 × m, 7 H, ArH), 7.94 (d, J = 7.3 Hz, 2 H). 13C NMR (100 MHz, CDCl3): δ = 21.49 (Me), 88.24, 91.97 (C≡ group), 108.31, 120.32, 126.25, 128.50, 128.71, 129.11, 131.40, 136.41, 138.34, 140.85 (CH=CH, ArC). Anal. Calcd for C17H14: C, 93.54; H, 6.46. Found: C, 93.47; H, 6.40
  • 19 Ghosh R, Zhang X, Achord P, Emge TJ, Krogh-Jespersen K, Goldman AS. J. Am. Chem. Soc. 2007; 129: 853
    Crossref