6094
R. R. Carter, J. K. Wyatt / Tetrahedron Letters 47 (2006) 6091–6094
without the formation of side products (Table 1, entries
and 8). The major side product in the coupling is
typically the reduced product, which in the case of aryl
bromides 1 and 5 could be eliminated under the condi-
tions described in this report. Further investigations into
these coupling reactions are in progress.
13. Typical Suzuki–Miyaura coupling conditions: Potassium
vinyltrifluoroborate (2) (258 mg, 1.92 mmol), cesium car-
bonate (378 mg, 1.16 mmol), PdCl (dppf)ÆCH Cl
2
7
2
2
(
25.6 mg, 0.0349 mmol) and benzyl 4-bromo-3,5-bis(benz-
yloxy)benzoate (1) (200 mg, 0.386 mmol) were suspended
in degassed THF (6.9 mL) and degassed deionized H
0.69 mL) in a 25 mL round bottom flask equipped with a
2
O
(
reflux condenser. The rust-red solution was completely
submerged in an oil bath and stirred at a temperature
between 85 and 90 ꢁC (reflux). After 24 h, another 9 mol %
Acknowledgements
of PdCl
2
(dppf)ÆCH
2
Cl
2
(25.6 mg, 0.0341 mmol) was
We would like to thank Professor Gary A. Molander for
his helpful discussions during this project. We would
like to acknowledge the NIH SC-INBRE # RR-03-
added. The reaction was considered complete after about
2 h, as determined by TLC. The resulting brown solution
was quenched with 10 mL of H O and extracted with Et O
7
2
2
(
20 mL · 3). The combined organic layers were washed
with 1 M HCl (20 mL) and brine (20 mL). The clear,
yellow solution was dried over MgSO , and filtered. The
0
10, ACS-PRF Type G #39541-GB1 for funding. We
would also like to thank the Department of Chemistry
and Biochemistry at the College of Charleston for
continuing support.
4
solvent was removed under reduced pressure using a
rotary evaporator. The red–brown residue was purified
3
using flash chromatography (3% EtOAc/2% CHCl /Hex-
anes) to yield 3 as a white solid in 73% yield (132 mg,
1
References and notes
0.294 mmol). Mp = 102–103 ꢁC. H NMR (CDCl ): d
3
7
.44–7.28 (m, 15H), 7.08 (dd, J = 18.1 and 12.2 Hz, 1H),
1
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6.25 (dd, J = 18.0 and 2.5 Hz, 1H), 5.52 (dd, J = 12.2 and
2.6 Hz, 1H), 5.34 (s, 2H), 5.12 (s, 4H). C NMR (CDCl ):
3
13
1
2
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H O
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5890 Series II GC with 30 m · 0.25 mm ID Zebron ZB-5
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