X. Fu et al. / Tetrahedron Letters 43 (2002) 6673–6676
6675
Triethylamine (49 mL, 1.3 equiv.) was slowly intro-
duced via addition funnel while maintaining the reac-
tion temperature to between 20 and 30°C. The mixture
was further agitated at 20–25°C and filtered upon the
completion of the reaction (<1% 1) as followed by
HPLC (Waters HPLC with PDA module, isocratic
mobile phase composed of 1:1 water and acetonitrile,
m-Bondpak C-18 column; UV 254 nm). The filtrate was
concentrated under reduced pressure, followed by sol-
vent replacement with N,N-dimethylacetamide to a vol-
ume of about 120 mL.
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With triphenylphosphine (1.05 g, 0.015 equiv.), palladi-
um(II) acetate (0.90 g, 0.015 equiv.), N,N-dimethyl-
formamide (60 mL), triethylamine (60 mL), N,N-
dimethylacetamide (30 mL) and phenylacetylene (44.1
mL, 1.5 equiv.) added, the mixture was stirred at
ambient temperature for 3.5 h. Following the comple-
tion of the reaction that was monitored by HPLC, the
mixture was diluted with 300 mL of toluene, filtered
through a Celite pad and washed with water to afford
a fairly clean product solution with a yield of 91.3%.
After evaporation of the solvent, the analytically pure
product was obtained by flash chromatography (1:2
ethyl acetate and n-heptane) as a yellow oil.
In summary, a synthetically useful palladium-catalyzed
cross coupling of vinyl tosylates and acetylenes has
been discovered as an efficient and cost effective
method for this type of chemical transformations. The
extremely mild reaction conditions, simple procedure
and high isolated yield also make it a superior method
over other existing processes.
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Acknowledgements
The authors thank Professor Li Deng for helpful dis-
cussions and Mr. Danny Angeles for experimental
assistant.
16. 1H and 13C NMR spectral data for compounds 4–10, 15.
Compound 4: 1H NMR (CDCl3): 7.51 (m, 2H, J=8.5),
7.40 (m, 3H), 6.31 (t, 1H, J=1.6 Hz), 2.57 (m, 2H), 2.46
(t, 3H, J=6.3 Hz), 2.08 (m, 2H).13C NMR (CDCl3): 199.1,
143.3, 132.8, 132.3, 129.9, 128.9, 122.4, 100.1, 88.8, 37.7,
30.9, 23.0
References
Compound 5: 1H NMR (CDCl3): 6.17 (t, 1H, J=1.4 Hz),
3.13 (s, 1H), 2.41 (m, 4H), 2.01–1.91 (m, 4H), 1.69–1.45
(m, 7H), 1.25 (m, 1H).13C NMR (CDCl3): 199.6, 144.2,
132.7, 104.7, 83.7, 69.3, 40.0, 37.6, 31.0, 25.5, 23.6, 22.9
Compound 6: 1H NMR (CDCl3): 6.27 (m, 1H, J=1.9 Hz),
6.17 (d, 1H, J=1.4 Hz), 2.47–2.39 (m, 4H), 2.16 (m, 4H),
2.03 (m, 2H), 1.62 (m, 4H).13C NMR (CDCl3): 199.1,
144.4, 138.7, 131.9, 128.8, 120.6, 102.5, 86.7, 37.6, 31.0,
29.1, 26.3, 23.1, 21.7
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Compound 7: 1H NMR (CDCl3): 6.14 (s, 1H), 4.68 (q, 1H,
J=6.6 Hz), 3.67 (broad s, 1H), 2.38 (m, 4H), 1.97 (m, 2H),
1.46 (d, 3H, J=6.7 Hz).13C NMR (CDCl3): 199.9, 144.3,
132.7, 103.0, 83.0, 58.7, 37.6, 30.8, 24.3, 22.8
Compound 8: 1H NMR (CDCl3): 6.10 (s, 1H), 3.73 (t, 2H,
J=6.5 Hz), 3.21 (broad s, 1H), 2.63 (t, 2H, J=6.5 Hz),
2.37 (m, 4H), 1.96 (m, 2H) 13C NMR (CDCl3): 199.9,
145.1, 132.4, 99.5, 81.8, 60.9, 37.6, 31.1, 24.4, 22.9
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