90
Y. Lee et al. / Journal of Organometallic Chemistry 769 (2014) 80e93
Table 8
Recycling tests of Pd catalyst in Sonogashira coupling reactions at 80 ꢀC in water.
Entry
1st
2nd
96
3rd
95
4th
93
5th
90
Yield (%)a
Quant.
Reaction conditions: 4-iodoacetophenone (4j, 1 mmol), 4-ethynylaniline (7b, 1.5 mmol, 1.5 eq.), Et3N (3 mmol, 3 eq.), H2O (2 mL), 1 equimolar % Pd catalyst, and a reaction time
of 30 min.
a
Isolated yield (the purity of the isolated product was confirmed by 1H NMR).
2H), 2.45 (s, 3H), 1.63e1.70 (m, 2H), 1.37e1.46 (m, 2H), 0.94 (t,
J ¼ 7.4 Hz, 3H). CAS Number: 163977-61-5.
(t, J ¼ 6.8 Hz, 2H), 3.88 (s, 3H), 1.66e1.68 (m, 2H), 1.61e1.65 (m, 2H),
0.92 (t, J ¼ 7.4 Hz, 3H). CAS Number: 216483-44-2.
Butyl (E)-3-(4-methoxyphenyl)acrylate (6d, Table 4, entry 4)
Butyl (E)-3-(4-nitrophenyl)acrylate (6l, Table 4, entry 12)
1H NMR (400 MHz, CDCl3):
d
7.61 (d, J ¼ 15.6 Hz, 1H), 7.45 (d,
1H NMR (400 MHz, CDCl3):
d
8.25 (d, J ¼ 9.2 Hz, 2H), 7.68 (m,
J ¼ 8.4 Hz, 2H), 6.88 (d, J ¼ 8.8 Hz, 2H), 6.29 (d, J ¼ 16.0 Hz, 1H), 4.17
(t, J ¼ 6.8 Hz, 2H), 1.62e1.70 (m, 2H), 1.36e1.46 (m, 2H), 0.94 (t,
J ¼ 7.4 Hz, 3H). CAS Number: 121725-19-7.
3H), 6.56 (d, J ¼ 16.0 Hz, 1H), 4.24 (t, J ¼ 6.6 Hz, 2H), 1.67e1.74 (m,
2H), 1.40e1.49 (m, 2H), 0.97 (t, J ¼ 7.4 Hz, 3H). CAS Number:
131061-15-9.
Butyl (E)-3-(4-fluorophenyl)acrylate (6e, Table 4, entry 5)
Butyl (E)-3-(4-cyanophenyl)acrylate (6m, Table 4, entry 13)
1H NMR (400 MHz, CDCl3):
d
7.64 (d, J ¼ 16.0 Hz, 1H), 7.51 (dd,
1H NMR (400 MHz, CDCl3):
d 7.57e7.66 (m, 5H), 6.49 (d,
J ¼ 8.0, 5.6 Hz, 2H), 7.07 (t, J ¼ 8.6 Hz, 2H), 6.36 (t, J ¼ 16.0 Hz, 1H),
4.21 (t, J ¼ 6.6 Hz, 2H), 1.65e1.72 (m, 2H), 1.39e1.48 (m, 2H), 0.96 (t,
J ¼ 7.2 Hz, 3H). CAS Number: 131061-12-6.
J ¼ 16.0 Hz,1H), 4.20 (t, J ¼ 6.6 Hz, 2H), 1.63e1.70 (m, 2H), 1.38e1.46
(m, 2H), 0.94 (t, J ¼ 7.4 Hz, 3H). CAS Number: 172418-41-6.
Butyl (E)-3-(naphthalen-1-yl)acrylate (6n, Table 4, entry 14)
1H NMR (400 MHz, CDCl3):
d
8.52 (d, J ¼ 16.0 Hz, 1H), 8.20 (d,
Butyl (E)-3-(4-chlorophenyl)acrylate (6f, Table 4, entry 6)
1H NMR (400 MHz, CDCl3):
d
7.60 (d, J ¼ 16.0 Hz, 1H), 7.43 (d,
J ¼ 8.4 Hz, 1H), 7.89 (t, J ¼ 7.2 Hz, 2H), 7.68 (d, J ¼ 7.2 Hz), 7.47e7.60
(m, 3H), 6.53 (d, J ¼ 15.6 Hz, 1H), 4.26 (t, J ¼ 6.6 Hz, 2H), 1.69e1.76
(m, 2H), 1.42e1.52 (m, 2H), 0.99 (t, J ¼ 7.4 Hz, 3H). CAS Number:
123230-71-7.
J ¼ 8.4 Hz, 2H), 7.33 (d, J ¼ 8.8 Hz), 6.39 (d, J ¼ 16.0 Hz, 1H), 4.18 (t,
J ¼ 6.6 Hz, 2H), 1.63e1.70 (m, 2H), 1.36e1.46 (m, 2H), 0.94 (t,
J ¼ 7.4 Hz, 3H). CAS Number: 123248-22-6.
Butyl (E)-3-(3-chlorophenyl)acrylate (6g, Table 4, entry 7)
Recycling tests of Pd catalyst in HeckeMizoroki coupling reactions
Two kinds of HeckeMizoroki coupling reactions were carried
out. The first five runs were with 1-iodo-4-nitrobenzene 4l and
butyl acrylate 5, and the second five runs were with methyl 4-
iodobenzoate 4k and butyl acrylate 5. The HeckeMizoroki
coupling reactions were performed as described above. After the
first reaction was complete, catalyst was recovered by simple
filtration and was air-dried. The recovered catalyst was successively
subjected to the next five runs of the coupling reaction under the
same reaction conditions as the first run.
1H NMR (400 MHz, CDCl3):
d
7.58 (d, J ¼ 16.0 Hz, 1H), 7.49 (t,
J ¼ 1.8 Hz, 1H), 7.27e7.38 (m, 3H), 6.42 (d, J ¼ 16.0 Hz, 1H), 4.19 (t,
J ¼ 6.6 Hz, 2H), 1.63e1.70 (m, 2H), 1.37e1.46 (m, 2H), 0.94 (t,
J ¼ 7.4 Hz, 3H). CAS Number: 131061-13-7.
Butyl (E)-3-(2-chlorophenyl)acrylate (6h, Table 4, entry 8)
1H NMR (400 MHz, CDCl3):
d
8.06 (d, J ¼ 16.0 Hz, 1H), 7.59 (dd,
J ¼ 7.2, 2.4 Hz, 1H), 7.39 (dd, J ¼ 7.8, 1.6 Hz, 1H), 7.24 (m, 2H), 6.41 (d,
J ¼ 16.0 Hz, 1H), 4.20 (t, J ¼ 6.8 Hz, 2H), 1.64e1.71 (m, 2H), 1.37e1.64
(m, 2H), 0.94 (t, J ¼ 7.4 Hz, 3H). CAS Number: 603952-32-5.
Application to Sonogashira coupling reactions
Butyl (E)-3-(4-bromophenyl)acrylate (6i, Table 4, entry 9)
1H NMR (400 MHz, CDCl3):
d
7.60 (d, J ¼ 16.0 Hz, 1H), 7.52 (d,
General procedure for the Sonogashira coupling reaction
J ¼ 8.4 Hz, 2H), 7.38 (d, J ¼ 8.4 Hz, 2H), 6.42 (d, J ¼ 16.0 Hz, 1H), 4.21
(d, J ¼ 6.8 Hz, 2H), 1.65e1.72 (m, 2H), 1.39e1.48 (m, 2H), 0.96 (t,
J ¼ 7.4 Hz, 3H). CAS Number: 131061-14-8.
A 10 mL round-bottom flask was charged with iodobenzene (4a,
1 mmol, 1 eq.), phenylacetylene (7a, 1.5 mmol, 1.5 eq.), triethyl-
amine (3 mmol, 3 eq.), H2O (2 mL), and Pd catalyst (0.01 mmol). The
flask was stirred at 80 ꢀC in air. The reaction was monitored by TLC
and GC. After the reaction was complete, the reaction mixture was
cooled to room temperature and ethyl acetate (5 mL) was added to
the flask. Afterward, the catalyst was filtered and washed with
water (10 mL) and ethyl acetate (10 mL). The aqueous phase was
extracted three times with 30 mL EtOAc. The organic phases were
collected together, dried over MgSO4, and filtered. The solvent was
then evaporated under reduced pressure. The pure product was
obtained via silica gel column chromatography with an eluent of
EtOAc and hexane. The resulting product was analyzed by 1H NMR
spectroscopy.
Butyl (E)-3-(4-acetylphenyl)acrylate (6j, Table 4, entry 10)
1H NMR (400 MHz, CDCl3):
d
7.94 (d, J ¼ 8.4 Hz, 2H), 7.67 (d,
J ¼ 16.0 Hz,1H), 7.59 (d, J ¼ 8.0 Hz, 2H), 6.50 (d, J ¼ 16.0 Hz,1H), 4.20
(t, J ¼ 6.6 Hz, 2H), 2.59 (s, 3H), 1.64e1.71 (m, 2H), 1.37e1.46 (m, 2H),
0.947 (t, J ¼ 7.4 Hz, 3H). CAS Number: 173464-57-8.
Methyl (E)-4-(3-butoxy-3-oxoprop-1-en-1-yl)benzoate (6k, Table 4,
entry 11)
1H NMR (400 MHz, CDCl3):
J ¼ 16.0 Hz, 1H), 7.54 (d, J ¼ 8.0 Hz, 2H), 6.47 (d, J ¼ 16.0 Hz, 1H), 4.17
d
8.00 (d, J ¼ 8.0 Hz, 2H), 7.64 (d,