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F. Luo et al. / Tetrahedron 66 (2010) 1399–1403
3.3.7. (E)-1,2-Bis(3-methoxyphenyl)ethene (2g)17 1H NMR (CDCl3,
.
HX
300 MHz):
d
7.31–7.28 (m, 2H), 7.15–7.08 (m, 6H), 6.85 (d, J¼8.1 Hz,
2H), 3.87 (s, 6H). 13C NMR (CDCl3, 75 MHz):
128.9, 119.3, 113.4, 111.7, 55.2.
d 159.9, 138.7, 129.7,
H
Pd
X
3.3.8. (E)-1,2-Dip-tolylethene (2h)18 1H NMR (CDCl3, 300 MHz):
.
Ar
R
Pd(0)
d
7.43 (d, J¼8.1 Hz, 4H), 7.18 (d, J¼8.0 Hz, 4H), 7.07 (s, 2H), 2.38
H
H
R
(s, 6H). 13C NMR (CDCl3, 75 MHz):
126.3, 21.2.
d 137.3, 134.7, 129.4, 127.6,
Ar
3.3.9. (E)-1-Chloro-4-styrylbenzene
(2i)13
.
1H
NMR
(CDCl3,
300 MHz):
d 7.51 (m, 2H), 7.45 (m 2H), 7.40–7.30 (m, 5H), 7.07 (s,
2H). 13C NMR (CDCl3, 75 MHz):
128.7, 127.8, 127.6, 127.3, 126.5.
d 136.9, 135.8, 133.1, 129.3, 128.8,
H
R
H
H
PdX
H
PdH
Ar
Ar
R
A
3.3.10. (E)-1-Fluoro-4-styrylbenzene
300 MHz): 7.50–7.44 (m, 4H), 7.37–7.32 (m, 2H), 7.27–7.24 (m,
1H), 7.07–6.97 (m, 4H). 13C NMR (CDCl3, 75 MHz):
162.4, 137.1,
(2j)14 1H NMR (CDCl3,
.
Ar
R
d
B
d
133.5, 128.7, 128.5 (d, J¼2.4 Hz), 127.9 (d, J¼7.8 Hz), 127.6, 127.5,
Et3SiX
HSiEt3
126.4, 115.6 (d, J¼21.4 Hz).
Scheme 3. Possible mechanism.
3.3.11. (E)-1-Nitro-4-styrylbenzene
(2k)19
.
1H
NMR
(CDCl3,
300 MHz):
d
8.23 (d, J¼8.8 Hz, 2H), 7.64 (d, J¼8.8 Hz, 2H), 7.56 (d,
3.3. Typical experimental procedure for palladium-catalyzed
reduction of alkynes into cis-alkenes
J¼8.3 Hz, 2H), 7.44–7.26 (m, 4H), 7.15 (d, J¼16.3 Hz, 1H). 13C NMR
(CDCl3, 75 MHz): d 143.8, 136.2, 133.3, 128.9, 128.85, 128.84, 127.0,
126.8, 126.3, 124.1.
Under air atmosphere, a reaction tube was charged with internal
alkynes (0.2 mmol), HSiEt3 (46.5 mg, 0.4 mmol), PdCl2(dppf)
(2.2 mg, 1.5 mol %), dppf (5.5 mg, 5 mol %), CH2Cl2/H2O (1/0.1 mL).
After the mixture was stirred at rt for 36 h, the solvent was evap-
orated under reduced pressure and the residue was purified by
flash column chromatography on a silica gel to give the product.
3.3.12. (E)-1-(4-Styrylphenyl)ethanone (2l)20
.
1H NMR (CDCl3,
300 MHz):
d
7.95 (d, J¼8.4 Hz, 2H), 7.59–7.53 (m, 4H), 7.41–7.30 (m,
3H), 7.22 (d, J¼16.4 Hz, 1H), 7.13 (d, J¼16.3 Hz, 1H), 2.60 (s, 3H). 13C
NMR (CDCl3, 75 MHz): d 197.5, 141.9, 136.7, 135.9, 131.4, 128.8, 128.7,
128.3, 127.4, 126.8, 126.5, 26.5.
3.3.1. (E)-1,2-Diphenylethene (2a)13
.
1H NMR (CDCl3, 300 MHz):
3.3.13. (E)-Ethyl 4-styrylbenzoate (2m)21 1H NMR (CDCl3,
.
d
7.56–7.53 (m, 4H), 7.41–7.36 (m, 4H), 7.31–7.28 (m, 2H,), 7.14 (s,
300 MHz):
d
8.04 (d, J¼8.4 Hz, 2H), 7.55 (m, 4H), 7.41–7.36 (m, 2H),
2H). 13C NMR (CDCl3, 75 MHz):
d
137.3, 128.7, 127.6, 126.5.
7.32–7.27 (m, 1H), 7.22 (d, J¼16.3 Hz, 1H), 7.12 (d, J¼16.3 Hz, 1H),
4.39 (q, J¼7.1 Hz, 2H), 1.41 (t, J¼7.1 Hz, 3H). 13C NMR (CDCl3,
3.3.2. (E)-1-(4-Methoxystyryl)benzene (2b)14
300 MHz):
.
1H NMR (CDCl3,
75 MHz): d 166.4, 141.7, 136.7, 131.1, 129.9, 129.2, 128.7, 128.2, 127.6,
d
7.51–7.45 (m, 4H), 7.38–7.33(m, 2H), 7.24–7.22 (m, 1H),
7.08 (d, J¼16.3 Hz, 1H), 6.94 (d, J¼16.3 Hz, 1H), 6.90 (d, J¼7.5 Hz,
2H), 3.84 (s, 3H). 13C NMR (CDCl3, 75 MHz):
159.3, 137.6, 130.1,
128.6, 128.2, 127.7, 127.2, 126.6, 126.2, 114.1, 55.30.
126.7, 126.2, 60.9, 14.3.
d
3.3.14. (E)-4-Styrylbenzonitrile (2n)22 1H NMR (CDCl3, 300 MHz):
.
d
7.65–7.52 (m, 6H), 7.42–7.32 (m, 3H), 7.22 (d, J¼16.3 Hz, 1H), 7.08
(d, J¼16.3 Hz, 1H). 13C NMR (CDCl3, 75 MHz):
d 141.8, 136.3, 132.5,
3.3.3. (E)-1-Methoxy-3-styrylbenzene (2c)15
.
1H NMR (CDCl3,
132.4, 128.8, 128.6, 126.9, 126.8, 126.7, 118.9, 110.5.
300 MHz): 7.55–7.52 (m, 2H), 7.40–7.35 (m, 2H), 7.30–7.27 (m, 2H),
7.15–7.07 (m, 4H), 6.86–6.84 (m, 1H). 13C NMR (CDCl3, 75 MHz):
159.9, 138.8, 137.2, 129.6, 129.0, 128.7, 128.6, 127.7, 126.5, 119.2,
d
3.3.15. (E)-2-Styrylpyridine (2o)14
d
.
1H NMR (CDCl3, 300 MHz):
d
8.62 (s, 1H), 7.72–7.58 (m, 4H), 7.44–7.18 (m, 6H). 13C NMR (CDCl3,
113.3, 111.8, 55.2.
75 MHz): d 155.4, 149.1, 136.9, 136.5, 133.3, 128.7, 128.6, 128.4, 127.3,
127.2, 122.1.
3.3.4. (E)-1-Methyl-2-styrylbenzene (2d)13 1H NMR (CDCl3,
.
300 MHz):
d
7.62–7.60 (m,1H), 7.56–7.53 (m, 2H), 7.41–7.19 (m, 7H),
3.3.16. (E)-1-(4-Methoxystyryl)cyclohexanol (2p)23 1H NMR (CDCl3,
.
7.01 (d, J¼16.1 Hz, 1H), 2.45 (s, 3H). 13C NMR (CDCl3, 75 MHz):
300 MHz):
d
7.33 (d, J¼8.5 Hz, 2H), 6.84 (d, J¼8.5 Hz, 2H), 6.64 (d,
d
137.7, 136.4, 135.8, 130.4, 129.9, 128.7, 127.6, 127.5, 126.5, 126.2,
J¼16.0 Hz, 1H), 6.39 (d, J¼16.1 Hz, 1H), 5.84 (s, 1H), 3.8 (s, 3H), 2.25–
125.4, 19.9.
2.17 (m, 4H), 1.74–1.61 (m, 4H), 0.87–0.83 (m, 2H). 13C NMR (CDCl3,
75 MHz):
26.1, 24.5, 22.6, 22.5.
d 158.7, 135.9, 130.8, 130.7, 129.7, 127.2, 124.1, 114.0, 55.3,
3.3.5. (E)-1-Methyl-4-styrylbenzene
(2e)13
.
1H NMR (CDCl3,
300 MHz):
d
7.54 (d, J¼7.5 Hz, 2H), 7.45–7.36 (m, 4H), 7.30–7.28 (m,
1H), 7.20 (d, J¼7.9 Hz, 2H), 7.12 (s, 2H), 2.40 (s, 3H). 13C NMR (CDCl3,
3.3.17. (1E,3E)-1,4-Diphenylbuta-1,3-diene (2q)24 1H NMR (CDCl3,
.
300 MHz): d 7.47–7.45 (m, 4H), 7.37–32 (m, 4H), 7.28–7.24 (m, 2H),
75 MHz):
d
137.5, 134.5, 129.4, 128.7, 128.6, 127.7, 127.4, 126.43,
126.40, 21.3.
7.01–6.95 (dd, 2H, J¼14.6 Hz, J¼12.0 Hz), 6.71–6.66 (dd, 2H,
J¼14.6 Hz, J¼11.9 Hz). 13C NMR (CDCl3, 75 MHz):
d 137.3, 132.8,
3.3.6. (E)-2-Styrylnaphthalene (2f)16
.
1H NMR (CDCl3, 300 MHz):
129.2, 128.6, 127.5, 126.4.
d
8.25 (d, J¼7.5 Hz, 1H), 7.95–7.76 (m, 4H), 7.65–7.63 (m, 2H), 7.57–
7.52 (m, 3), 7.44–7.41 (m, 1H), 7.19 (d, J¼16.0 Hz, 1H). 13C NMR
3.3.18. (Z)-1,2-Diphenylethene (3a)13
7.28–7.21 (m, 10H), 6.63 (s, 2H). 13C NMR (CDCl3, 75 MHz):
130.2, 128.9, 128.2, 127.1.
.
1H NMR (CDCl3, 300 MHz):
(CDCl3, 75 MHz):
128.0, 127.8, 126.7, 126.1, 125.8, 125.79, 125.70, 123.8, 123.6.
d
137.6, 135.0, 133.7, 131.7, 131.4, 128.8, 128.6,
d
d
137.2,