4
168 J . Org. Chem., Vol. 66, No. 12, 2001
Erd e´ lyi and Gogoll
Ma ter ia ls. The starting materials were purchased from
the microwave cavity. Then the reaction mixture was treated
with diethyl ether, filtered, and poured into 0.1 M aqueous
HCl (5-10 mL). Subsequent workup followed the procedure
described in method B.
commercial suppliers and were used without purification with
the exception of 4-iodoaniline, which was recrystallized from
ethanol twice. 2-Iodoaniline (98%), 3-iodoaniline (98%), methyl
2
-bromobenzoate (98%), methyl 4-bromobenzoate (99%), bro-
3 2 2
Meth od D. The aryl triflate (0.90 mmol), Pd(PPh ) Cl (12.8
mobenzene (99%), and 2-chloropyridine (99%) were obtained
from Aldrich. 4-Iodoaniline (97%), 4-iodoanisole (98%), and
mg, 0.02 mmol), CuI (6.9 mg, 0.04 mmol), lithium chloride (57.8
mg, 1.36 mmol), trimethylsilylacetylene (0.14 mL, 1.00 mmol),
diethylamine (1.5 mL, 13.60 mmol), and dimethylformamide
(0.5 mL) were stirred under nitrogen in a heavy-walled Smith
process vial at 120 °C for 5 min. Subsequent workup followed
the procedure described for method B.
2
-bromothiophene (purum) were purchased from Fluka. Meth-
yl 2-bromobenzoate (98%), methyl 3-bromobenzoate (98%), and
1
2
4
-iodo-4-trifluoromethylbenzene (99%) were from Lancaster.
-Iodoanisole (97%), 3-iodoanisole (97%), 2-bromoanisole (97%),
-bromoanisole (98%), iodobenzene (98%), 2-iodothiophene
3 2 2
Meth od E. The aryl bromide (0.90 mmol), Pd(PPh ) Cl
(
98%), and 3-bromothiophene (96%) were from J anssen Chim-
(44.7 mg, 0.06 mmol), triphenylphosphine (47.7 mg, 0.18
mmol), trimethylsilylacetylene (0.14 mL, 1.00 mmol), diethy-
lamine (1.5 mL, 13.60 mmol), and dimethylformamide (0.5 mL)
were stirred under nitrogen in a heavy-walled Smith process
vial at 120 °C for 20 min in the microwave cavity. Subsequent
workup followed the procedure described for Method C.
ica, Belgium. 4-Bromoaniline (98%) and 3-bromopyridine (98%)
were from Merck. 1-Bromo-4-trifluoromethylbenzene (99%)
was from Acros. 3-Bromoanisole (99%) was from Ega Chemie
and 3-bromoaniline from Theodor Schuchardt GmbH&Co,
M u¨ nchen. The reagents diethylamine (98%), trimethylsily-
lacetylene (98%), and Pd(PPh
3
)
2
Cl
2
(98%) were from Aldrich,
3 2 2
Meth od F . The aryl iodide (0.90 mmol), Pd(PPh ) Cl (6.4
cuprous iodide (99%) and triphenylphosphine (98%) were from
Merck, and dimethylformamide (99%) was from Fluka. The
mg, 0.02 mmol), CuI (3.5 mg, 0.04 mmol), trimethylsilylacety-
lene (0.14 mL, 1.00 mmol), diethylamine (1.5 mL, 13.60 mmol),
and dimethylformamide (0.5 mL) were stirred under nitrogen
in a heavy-walled Smith process vial at 120 °C for 10 min in
the microwave cavity. The subsequent workup followed the
procedure described for method B.
3 4
Pd(PPh ) (99%) was received from Acros. The aryl triflates
3
2
were prepared following literature procedures. All products
are known and were identified by comparison with their
reported MS and NMR literature data.
Meth od A1. The aryl iodide (0.9 mmol), Pd(PPh
3
)
2
Cl
2
(12.8
The weighted yields of method B, C, D, E, and F include
triphenylphosphine; the exact yields obtained by NMR quan-
tification can be seen in Table 1 or are mentioned in the text.
2-(Tr im et h ylsilylet h yn yl)a n ilin e. Method A1, entry
1A1: brown oil, 167.8 mg, 0.90 mmol, 98%. Method A2, entry
mg, 0.02 mmol), CuI (6.9 mg, 0.04 mmol), trimethylsilylacety-
lene (0.14 mL, 1.00 mmol), diethylamine (1.5 mL, 13.60 mmol),
and dimethylformamide (0.5 mL) were mixed and stirred
under nitrogen in a heavy-walled Smith process vial at 25 °C
for 5 h. Then, the reaction mixture was poured into 0.1 M
aqueous HCl (5-10 mL) and extracted three times with diethyl
ether (5-10 mL). The combined organic layers were washed
1A2: brown oil, 204.4 mg. Method B, entry 1B: brown oil,
1
210.0 mg; H NMR (400 MHz, CDCl
3
) δ 7.29 (dd, J ) 1.7, 7.5
Hz, 1H, ArH), 7.11 (ddd, J ) 1.7, 7.5, 8.2 Hz, 1H ArH), 6.68
(dd, J ) 1.1, 8.2 Hz, 1H, ArH), 6.66 (ddd, J ) 1.1, 7.5, 7.5 Hz,
1H, ArH), 4.07 (br s, 2H, NH
with concentrated aqueous NaHCO solution (5-10 mL) and
3
water (5-10 mL), re-extracting the aqueous phases in each
case two times with diethyl ether, and then concentrated under
reduced pressure. Then, the residue was purified by flash
chromatography (silica gel 60, particle size 0.040-0.063 mm,
Merck; hexane/ethyl acetate 12:1). The combined product
fractions were concentrated on a rotatory evaporator, followed
by removal of remaining solvent under reduced pressure
overnight.
2 3 3
), 0.27 (s, 9H, RSi(CH ) ); MS
+
m/z (relative intensity) 189 (61, M ), 174 (100).
3-(Tr im et h ylsilylet h yn yl)a n ilin e. Method A1, entry
2A1: brown oil, 167.8 mg, 0.90 mmol, 99%. Method A2, entry
2A2: brown oil, 244.4 mg. Method B, entry 2B: brown oil;
1
259.1 mg. Method C, entry 4C: yellow oil, 239.5 mg; H NMR
(400 MHz, CDCl ) δ 7.08 (dd, J ) 7.7, 8.0 Hz, 1H, ArH), 6.87
3
(ddd, J ) 0.7, 1.1, 7.7 Hz, 1H, ArH), 6.79 (dd, J ) 1.1, 2.6 Hz,
1H, ArH), 6.63 (ddd, J ) 0.7, 2.6, 8.0 Hz, 1H, ArH), 3.6 (br s,
Meth od A2. Procedure as described for method A1 except
for temperature (120 °C) and reaction time (5 min) and the
workup procedure as described for method B. The Smith
Process Vial, containing a magnetic stir bar, was placed in an
oil bath that was kept at 120 °C. The reaction mixture assumed
the temperature of the oil bath within 1 min and was stirred
at this temperature for 5 min.
2H, NH
189 (42, M ), 174 (100).
2 3 3
), 0.25 (s, 9H, RSi(CH ) ); MS m/z (relative intensity)
+
4-(Tr im et h ylsilylet h yn yl)a n ilin e. Method A1, entry
3A1: yellowish solid, 164.9 mg, 0.88 mmol, 97%. Method A2,
entry 3A2: yellowish solid, 259.8 mg. Method B, entry 3B:
brown oil, 191.1 mg. Method C, entry 5C: yellow oil, 257.9
1
Meth od B. The aryl iodide (0.90 mmol), Pd(PPh
3
)
2
Cl
2
(12.8
mg; H NMR (400 MHz, CDCl
3
) δ 7.26 (AA′XX′, 2H, ArH), 6.55
mg, 0.02 mmol), CuI (6.9 mg, 0.04 mmol), trimethylsilylacety-
lene (0.14 mL, 1.00 mmol), diethylamine (1.5 mL, 13.60 mmol),
and dimethylformamide (0.5 mL) were stirred under nitrogen
in a heavy-walled Smith process vial at 120 °C for 5 min in
the microwave cavity. The mixture was then poured into 0.1
M aqueous HCl (5-10 mL) and extracted three times with
diethyl ether (5-10 mL). The combined organic layers were
(AA′XX′, 2H, ArH), 3.80 (br s, 2H, NH
(CH ); MS m/z (relative intensity) 189 (42, M ), 174 (100).
2
), 0.22 (s, 9H, RSi-
+
3 3
)
Meth yl 2-(Tr im eth ylsylileth yn yl)ben zoa te. Method B,
entry 6B: brown oil, 275.3 mg. Method C, entry 7C: 249.8
1
mg; H NMR (400 MHz, CDCl
3
) δ 7.89 (ddd, J ) 0.6, 1.5, 7.9
Hz, 1H, ArH), 7.57 (ddd, J ) 0.6, 1.5, 7.7 Hz, 1H, ArH), 7.43
(ddd, J ) 1.5, 7.5, 7.9 Hz, 1H, ArH), 7.36 (ddd, J ) 1.5, 7.5,
washed with concentrated aqueous NaHCO
3
solution (5-10
7.7 Hz, 1H, ArH), 3.90 (s, 3H, ArCOOCH
(CH
(100).
Meth yl 3-(Tr im eth ylsylileth yn yl)ben zoa te. Method C,
3
), 0.25 (s, 9H, RSi-
+
mL) and water (5-10 mL), re-extracting the aqueous phases
in each case two times with diethyl ether (5-10 mL), then
concentrated under reduced pressure. After the residue was
treated with pentane, it was filtered through Celite. Then the
solvent was evaporated on a rotatory evaporator and the
3 3
) ); MS m/z (relative intensity) 232 (4, M ), 217 (27), 187
1
3
entry 8C: yellowish oil, 259.4 mg; H NMR (400 MHz, CDCl )
δ 8.13 (ddd, J ) 0.6, 1.7, 1.7 Hz, 1H, ArH), 7.96 (ddd, J ) 1.1,
1.7, 7.9 Hz, 1H, ArH), 7.63 (ddd, J ) 1.1, 1.7, 7.7 Hz, 1H, ArH),
1
product was quantified by H NMR.
7
.37 (ddd, J ) 0.6, 7.7, 7.9 Hz, 1H, ArH), 3.90 (s, 3H,
Meth od C. The aryl bromide or chloride (0.90 mmol), Pd-
PPh ) Cl (31.9 mg, 0.05 mmol), CuI (8.7 mg, 0.05 mmol),
3 2 2
triphenylphosphine (47.7 mg, 0.18 mmol), trimethylsilylacety-
lene (0.14 mL, 1.00 mmol), diethylamine (1.5 mL, 13.60 mmol),
and dimethylformamide (0.5 mL) were stirred under nitrogen
in a heavy-walled Smith process vial at 120 °C for 25 min in
ArCOOCH
sity) 232 (14, M ) 217 (100).
Meth yl 4-(Tr im eth ylsylileth yn yl)ben zoa te. Method C,
entry 9C: yellowish oil, 262.2 mg; H NMR (400 MHz, CDCl
δ 7.97 (AA′XX′, 2H, ArH), 7.51 (AA′XX′, 2H, ArH), 3.90 (s, 3H,
ArCOOCH ), 0.25 (s, 9H, RSi(CH ); MS m/z (relative inten-
sity) 232 (14, M ) 217 (100).
-(Tr im eth ylsilyleth yn yl)a n isole. Method B, entry 10B:
brown oil, 263.2 mg. Method C, entry 13C: yellowish oil, 248.6
3 3 3
), 0.25 (s, 9H, RSi(CH ) ); MS m/z (relative inten-
(
+
1
3
)
3
3 3
)
+
(
31) For preparative purposes, triphenylphosphine-free product
might be isolated by flash chromatography; see method A.
32) Sa a´ , J . M.; Dopico, M.; Martorell, G.; Grac ´ı a-Raso, A. J . Org.
Chem. 1990, 55, 991.
2
(
1
mg; H NMR (400 MHz, CDCl ) δ 7.43 (dd, J ) 1.8, 7.5 Hz,
3