Notes
J . Org. Chem., Vol. 63, No. 25, 1998 9603
room temperature for 20 min, and Pd(PPh3)4 (58 mg, 0.05 mmol,
5 mol %) and p-methylphenyl iodide (262 mg, 1.2 mmol) were
added. After the reaction was complete, as monitored by TLC
(eluent: petroleum ether (60-90 °C)), it was quenched with
water and extracted with petroleum ether (60-90 °C). Drying
over MgSO4, rotary evaporation, and chromatography on silica
gel (eluent: petroleum ether (60-90 °C)) afforded 163 mg (79%)
of 1-phenyl-1-(4′-methyl-phenyl)propadiene (2b): liquid; 1H
NMR(300 MHz) δ 2.39 (s, 3H), 5.26 (s, 2H), 7.10-7.45 (m, 9H);
MS (m/e) 206 (M+, 100); IR (neat) 1940 cm-1 ; HRMS calcd for
Sch em e 3
C
16H14 206.1092, found 206.1092.
The following compounds were prepared similarly; the cata-
lyst used and reaction time were listed in Table 1.
1,1-Diphenylpropadiene (2a ) was isolated in 83% yield.
1-P h en yl-1-(4′-m et h oxylp h en yl)p r op a d ien e (2c): yield
69%; liquid; 1H NMR(300 MHz) δ 3.80 (s, 3H), 5.32 (s, 2H), 6.90-
(d, J ) 6.82 Hz, 2H), 7.20-7.40 (m, 7H); 13C NMR δ 209.74,
159.01, 136.63, 129.61, 128.48, 128.42, 127.25, 127.19, 114.07,-
108.76, 77.89, 55.18; MS (m/e) 222 (M+, 100); IR (neat) 1939
cm-1; HRMS calcd for C16H14O 222.1041, found 222.1048.
1-P h en yl-1-(4′-n itr op h en yl)p r op a d ien e (2d ): yield 55%;
liquid; 1H NMR (300 MHz) δ 5.38 (s, 2H), 7.25-7.45 (m, 5H),
7.50 (d, J ) 8.71 Hz, 2H), 8.18 (d, J ) 8.72 Hz, 2H); MS (m/e)
237 (M+, 100); IR (neat) 1920 cm-1; HRMS calcd for C15H11NO2
237.0787, found 237.0787.
1-P h en yl-1-(1′-n a p h th yl)p r op a d ien e (2e): yield 55%; liq-
uid; 1H NMR (300 MHz) δ 5.23 (s, 2H), 7.10-7.60 (m, 9H), 7.80-
7.95 (m, 3H); MS (m/e) 242 (M+, 70.64), 241 (100); IR (neat) 1930
cm-1; HRMS calcd for C19H14 242.1092, found 242.1115.
For the synthesis of compounds 2f-i, the monolithiation was
carried out at room temperature.
Exp er im en ta l Section
Ma ter ia ls. n-BuLi (from Fluka, 1.6 M in hexanes), bro-
mobenzene, iodobenzene, 1-iodonaphthalene, p-methylphenyl
iodide, p-nitrophenyl bromide, and p-methoxyphenyl iodide are
commercially available and used as is. 1H NMR spectra were
measured using CDCl3 as the solvent and Me4Si as the internal
standard. The NMR yields were measured using CH2Br2 as the
internal standard.
Rea ction of 1-P h en yl-1-p r op yn e, n -Bu Li, a n d Iod oben -
zen e. To a solution of HgCl2 (4 mg, 0.015 mmol, 1.5 mol %)
and 1-phenyl-1-propyne (116 mg, 1 mmol) in THF (2 mL) in a
dry Schlenk tube was added n-BuLi (0.7 mL, 1.6 M in hexanes,
1.1 mmol) at -78 °C under N2. After 100 min at -78 °C,
iodobenzene (224 mg, 1.1 mmol) in THF was added. No reaction
was observed after 4 h at room temperature, as monitored by
TLC (eluent: petroleum ether (60-90 °C)).
P d Cl2(P P h 3)2-Ca ta lyzed Rea ction of Iod oben zen e w ith
th e Or ga n olith iu m s F or m ed by th e Rea ction of 1-P h en yl-
1-p r op yn e a n d n -Bu Li in th e P r esen ce of 1.5 m ol % HgCl2.
To a solution of HgCl2 (4 mg, 0.015 mmol, 1.5 mol %) and
1-phenyl-1-propyne (116 mg, 1 mmol) in THF (2 mL) in a dry
Schlenk tube was added n-BuLi (0.7 mL, 1.6 M in hexanes, 1.1
mmol) at -78 °C under N2. After 100 min at -78 °C, PdCl2-
(PPh3)2 (36 mg, 0.05 mmol, 5 mol %) and phenyl iodide (224 mg,
1.1 mmol) were added. No reaction was observed after 7 h at
room temperature, as monitored by TLC.
1,1-Dip h en yl-1,2-h exa d ien e (2f): yield 75%; liquid; 1H NMR
(300 MHz) δ 1.04 (t, J ) 7.35 Hz, 3H), 1.50-1.80 (m, 2H), 2.45-
2.65 (m, 2H), 6.55 (t, J ) 3.05 Hz,1H), 7.10-7.60 (m, 10H); MS
(m/e) 234 (M+, 16.42), 205 (100); IR (neat) 1928 cm-1; HRMS
calcd for C18H18 234.1404, found 234.1413.
1-P h en yl-1-(4′-m eth ylp h en yl)-1,2-h exa d ien e (2g): yield
68%; liquid; 1H NMR (300 MHz) δ 1.02 (t, J ) 7.35 Hz, 3H),
1.55-1.75 (m, 2H), 2.35 (s, 3H), 2.45-2.65 (m, 2H), 6.53 (t, J )
3.05, 1H), 7.05-7.45(m, 9H); MS(m/e) 248 (M+, 50.88), 205 (100);
IR (neat) 1926 cm-1; HRMS calcd for C19H20 248.1560, found
248.1570.
1-P h en yl-1-(4′-m eth oxylp h en yl)-1,2-h exa d ien e (2h ): yield
45%; liquid; 1H NMR (300 MHz) δ 1.02 (t, J ) 7.35 Hz, 3H),
1.50-1.75 (m, 2H), 2.40-2.65 (m, 2H), 3.82 (s, 3H), 6.53 (t, J )
3.05 Hz, 1H), 6.87 (d, J ) 6.82 Hz, 2H), 7.15-7.45 (m, 7H); MS
(m/e) 264 (M+, 100); IR (neat) 1935 cm-1; HRMS calcd for
C
19H20O 264.1059, found 264.1515.
1-P h en yl-1-(1′-n a p h th yl)-1,2-h exa d ien e (2i): yield 54%;
liquid; 1H NMR (300 MHz) δ 1.03 (t, J ) 7.31 Hz, 3H), 1.55-
1.80 (m, 2H), 2.45-2.86 (m, 2H), 6.35 (t, J ) 2.95 Hz, 1H), 7.18-
7.65 (m, 9H), 7.70-7.95 (m, 2H), 8.20-8.30 (m, 1H); MS (m/e)
284 (M+, 41.92), 241 (100); IR (neat) 1939 cm-1; HRMS calcd
for C22H20 284.1560, found 284.1565.
P d Cl2(P P h 3)2-Ca ta lyzed Cou p lin g Rea ction of Ar yl Io-
d id es w it h Or ga n ozin cs F or m ed b y t h e R ea ct ion of
1-P h en yl-1-p r op yn e, n -Bu Li, a n d Zn Br 2 in th e Absen ce of
HgCl2. To a solution of 1-phenyl-1-propyne (116 mg, 1 mmol)
in THF (2 mL) in a dry Schlenk tube was added n-BuLi (0.7
mL, 1.6 M in hexanes, 1.1 mmol) at -78 °C under N2. After
100 min at -78 °C, dry ZnBr2 (338 mg, 1.5 mmol) in THF (5
mL) was added. After 10 min at this temperature the reaction
mixture was warmed to room temperature for 20 min, PdCl2-
(PPh3)2 (36 mg, 0.05 mmol, 5 mol %) and phenyl iodide (224 mg,
1.1 mmol) were added at room temperature, and the resulting
mixture was stirred. After the reaction was complete, as
monitored by TLC (eluent: petroleum ether (60-90 °C)), it was
quenched with water and extracted with petroleum ether (60-
90 °C). Drying over MgSO4 and rotary evaporation afforded 1,1-
Qu en ch in g of th e Rea ction Mixtu r e of Allen ylzin c
Br om id e a n d P r op a r gylzin c Br om id e w ith H2O. To a
solution of HgCl2 (4 mg, 0.015 mmol, 1.5 mol %) and 1-phenyl-
1-propyne (116 mg, 1 mmol) in THF (2 mL) in a dry Schlenk
tube was added n-BuLi (0.7 mL, 1.6 M in hexanes, 1.1 mmol) at
-78 °C under N2. After 100 min at -78 °C, dry ZnBr2 (338 mg,
1.5 mmol) in THF (5 mL) was added. After 10 min at this
temperature, the reaction mixture was warmed to room tem-
perature for 20 min, quenched with water, extracted with diethyl
ether, and dried over MgSO4. Rotary evaporation afforded the
crude products, which were analyzed by 1H NMR spectroscopy
using CH2Br2 as the internal standard. 1-Phenylpropadiene:20
yield 44% by NMR; 1H NMR (300 MHz) δ 5.10 (d, J ) 6.75 Hz,
2H), 6.10 (t, J ) 6.75 Hz, 1H), 7.05-7.30 (m, 5H). 1-Phenyl-1-
propyne: yield 38% by NMR.
diphenylpropadiene (2a )13 in 62% NMR yield: liquid; H NMR
1
(300 MHz) δ 5.30 (s, 2H), 7.20-7.50 (m, 10H); MS (m/e) 192 (M+,
100); IR (neat) 1938 cm-1
.
P d (0)-Ca ta lyzed Cou p lin g Rea ction of Ar yl Iod id es w ith
Or ga n ozin cs F or m ed in th e P r esen ce of HgCl2. Syn th esis
of 1-P h en y-1-(4′-m eth ylp h en yl)p r op a d ien e (2b). Typ ica l
P r oced u r e. To a solution of HgCl2 (4 mg, 0.015 mmol, 1.5 mol
%) and 1-phenyl-1-propyne (116 mg, 1 mmol) in THF (2 mL) in
a dry Schlenk tube was added n-BuLi (0.7 mL, 1.6 M in hexanes,
1.1 mmol) at -78 °C under N2. After 100 min at -78 °C, dry
ZnBr2 (338 mg, 1.5 mmol) in THF (5 mL) was added. After 10
min at this temperature, the reaction mixture was warmed to
Ack n ow led gm en t. We thank the NNSF of China,
Laboratory of Organometallic Chemistry, Chinese Acad-
emy of Sciences, and Shanghai Institute of Organic
Chemistry for financial support.
(20) Skattebol, L. Acta Chem. Scand. 1963, 17, 1683.