Bergbreiter and Yang
JOCArticle
1
mixture to give a white solid (0.10 g, 0.26 mmol, 6% yield). H
NMR (500 MHz, C
aqueous EtOH (3 ꢀ 50 mL), and acetonitrile (7 ꢀ 20 mL), then
dried over anhydrous MgSO
4
. The solvent was evaporated
6 6
D ): δ 0.99 (d, J = 6.6 Hz, 6 H), 1.97 (t, J =
under reduced pressure to afford a crude product that was
purified by silica gel column chromatography with hexane as
eluting solvent to afford a colorless oil (1.84 g, 1.1 mmol, 26%
7.4 Hz, 2 H), 2.22-2.34 (m, 1 H), 6.94-7.04 (m, 6 H), 7.91-7.97
1
3
(m, 4 H). C NMR (125 MHz, C D ): δ 24.8 (d, J31 13 = 10.0
6
6
P- C
Hz), 27.2 (d, J31P-13C = 10.0 Hz), 37.1 (d, J31P-13C = 13.7 Hz),
128.8 (d, J31P-13C = 9.8 Hz), 129.8, 133.9 (d, J31P-13C = 16.7
1
yield). H NMR (300 MHz, C
6
D
6
): δ 0.80-1.90 (m, 183 H),
3
1
1
5
.90-2.00 (dd, J = 13.4, 8.1 Hz, 1 H), 2.06-2.18 (dd, J = 13.4,
Hz), 135.2 (d, J31P-13C = 26.1 Hz). P NMR (121 MHz, C
δ -0.7. Mp 191-193 °C. HRMS calcd for [(C H -
6 6
D ):
13
.5 Hz, 1 H), 7.02-7.13 (m, 6 H), 7.43-7.54 (m, 4 H). C NMR
): δ 14.4, multiple peaks between 20 and 41 and
1
6
19
þ
2
PAg) Cl] 733.0239, found 733.0394.
(
125 MHz, C
6
D
6
5
5-61, 128.4, 128.6 (d, J31P-13C = 6.2 Hz), 128.7 (d, J31P-13C
P-
31P-13
Hz). P NMR (121 MHz, C
=
Synthesis of Poly(ethylene glycol)triarylphosphine (11). This
phosphine was prepared by a literature procedure. The product
9
5
Hz), 140.0 (d, J
.1 Hz), 133.0 (d, J31 13 = 18.5 Hz), 133.6 (d, J
31P-13
= 19.3
= 14.4
C
C
= 15.2 Hz), 140.2 (d, J
31P-13
was precipitated with diethyl ether (500 mL) and was characteri-
zed by H and P NMR spectroscopy. The product was col-
lected by filtration as a white solid and contaminated with 20%
C
C
31
1
31
D
6 6
): δ -19.5.
Synthesis of Polyisobutyldiphenylphosphine Silver Iodide
PIB-CH PPh AgI) (2). The PIB phosphine 1 (0.041 g, 0.03
1
(
phosphine oxide. H NMR (500 MHz, CDCl ): δ 3.32, (s, 3 H),
2
2
3
mmol) and silver iodide (0.013 g, 0.05 mmol) were placed in a
5-mL round-bottomed flask equipped with a magnetic stir bar.
Then CH Cl (3 mL) was added to the flask and the reaction
mixture was stirred at room temperature for 54 h in the dark.
The suspension was filtered and the solvent was evaporated
under reduced pressure to afford a colorless oil (0.048 g, 0.03
3.42-3.83 (m, 218 H), 4.04-4.08 (m, 2H), 6.79-6.85 (m, 2 H),
3
1
2
7.16-7.28 (m, 12 H). P NMR (121 MHz, CDCl ): δ - 6.5.
3
2
2
Poly(ethylene glycol)triarylphosphine Complexes of Silver
Iodide and Silver Chloride (12 and 13, respectively). Complexes
12 and 13 were prepared from the phosphine 11 and AgI or AgCl
with use of a procedure analogous to that used to prepare PIB-
1
mmol, 99% yield). H NMR (300 MHz, C D ): δ 0.77-2.38
PPh complexes of AgI and AgCl. The silver halide complexes so
2
6
6
1
3
1 31
formed were characterized by H and P NMR spectroscopy
(
(
m, 185 H), 7.03-7.25 (m, 6 H), 7.74-8.00 (m, 4 H). C NMR
1
and were contaminated with up to 25% phosphine oxide. 12: H
75 MHz, C
5-60, and 128-136. P NMR (121 MHz, C
Synthesis of Polyisobutyldiphenylphosphine Silver Chloride
PIB-CH PPh AgCl) (3). The same procedure used to prepare
was used substituting AgCl (0.010 g, 0.07 mmol) for AgI. The
D
6 6
): δ 14.4, 15.2, multiple peaks between 24 and 41,
3
1
5
6
6
D ): δ -15.6.
NMR (500 MHz, CD
2 2
Cl ): δ 3.33, (s, 3 H), 3.42-3.86 (m, 218
H), 4.06-4.10 (m, 2H), 6.83-6.88 (m, 2 H), 7.26-7.33 (m, 4 H),
3
1
(
2
2
7.35-7.41 (m, 2 H), 7.43-7.51 (m, 6 H). P NMR (121 MHz,
1
2
CD
2
Cl
2
2 2
): δ - 3.4. 13: H NMR (300 MHz, CD Cl ): δ 3.32, (s,
product was isolated as a colorless oil (0.052 g, 0.03 mmol, 99%
3 H), 3.32-3.84 (m, 218 H), 4.02-4.09 (m, 2 H), 6.80-6.88 (m,
2 H), 7.24-7.50 (m, 12 H). P NMR (121 MHz, CD Cl ): δ 7.7.
1
31
yield). H NMR (300 MHz, C D ): δ 0.70-1.97 (m, 183 H),
6
6
2
2
1
3
2
.00-2.43 (m, 2 H), 6.98-7.14 (m, 6 H), 7.75-8.09 (m, 4 H).
C
Synthesis of (4-Methoxyphenyl)diphenylphosphine (14). To a
250-mL round-bottomed flask equipped with a magnetic stirrer
was added 4-bromoanisole (5.61 g, 30.0 mmol) and THF
(100 mL). The flask was immersed in a dry ice-acetone bath
for 30 min before BuLi (20 mL, 1.6 M in hexanes, 32.0 mmol)
was added. The reaction mixture was stirred at -78 °C for
60 min at which point chlorodiphenylphosphine (7.2 mL,
40 mmol in 20 mL of THF) was added. The reaction mixture
was stirred at -78 °C for 3 h and then warmed to room
temperature and stirred overnight. Then saturated aqueous
NMR (75 MHz, C
5-60, and 128-134. P NMR (121 MHz, C
Synthesis of Isobutyldiphenylphosphine (4). Isobutylmagne-
6 6
D ): δ multiple peaks between 24 and 38,
31
5
6 6
D ): δ -2.0.
sium bromide (30 mL, 1.25 M in THF) was cooled to 0 °C and
chlorodiphenylphosphine (6.9 mL, 37.6 mmol) was added drop-
wise. The reaction mixture was warmed to room temperature
and stirred for 24 h. Then saturated aqueous NH Cl (50 mL)
4
was added to quench the reaction mixture followed by addition
of ethyl acetate (50 mL). The organic layer was separated and
washed with H
anhydrous MgSO
pressure to afford the crude product, which was further purified
by vacuum distillation to give a colorless liquid (4.55 g, 18.8
2
O (50 mL) and brine (50 mL) and dried over
. The solvent was evaporated under reduced
NH
reaction and the organic phase was separated. The organic
phase was washed with H O (50 mL) and brine (50 mL) and
dried over anhydrous MgSO . The solvent was removed under
reduced pressure to afford a crude product that was purified by
silica gel column chromatography with use of hexane and
CH Cl (hexane:CH Cl = 4:1) to afford a colorless oil that
2 2 2 2
turned into a solid on standing. The solid was further recrys-
tallized from ethanol to give colorless prisms (5.04 g, 17.2 mmol,
4 2
Cl (50 mL) and H O (50 mL) were added to quench the
4
2
4
1
mmol, 50% yield). H NMR (300 MHz, C D ): δ 0.98 (d, J =
6
6
6
.3 Hz, 6 H), 1.55-1.77 (m, 1 H), 1.89 (d, J = 7.0 Hz, 2 H),
13
7
.00-7.12 (m, 6 H), 7.39-7.47 (m, 4 H). C NMR (75 MHz,
): δ 24.3 (d, J31P-13C = 9.6 Hz), 26.4 (d, J31P-13C = 14.0
Hz), 38.9 (d, J31P-13C = 13.8 Hz), 128.5, 128.6 (d, J31P-13C
.6 Hz), 133.1 (d, J31P-13C = 18.8 Hz), 140.2 (d, J31P-13C = 14.3
C
D
6 6
=
1
57% yield). H NMR (500 MHz, CDCl
6.89-6.95 (m, 2 H), 7.28-7.43 (m, 12 H). C NMR (75 MHz,
6
3
): δ 3.82, (s, 3 H),
31
13
Hz). P NMR (121 MHz, C
Synthesis of Isobutyldiphenylphosphine Silver Iodide ((CH
CHCH PPh AgI) (5). The same procedure used to prepare 2
D
6 6
): δ -19.5.
)
2
-
CDCl
6.8 Hz), 128.4 (d, J31P-13
19.0 Hz), 135.6 (d, J31P-13
3
): δ 55.1, 114.2 (d, J P-
3
1
13C=8.1 Hz), 127.3 (d, J
31P-13
31P-13
C
C
=
=
3
C
= 6.8 Hz), 128.5, 133.4 (d, J
2
2
C
= 21.3 Hz), 137.6 (d, J
31P-13
C
= 9.3
was used. The product was recrystallized from a mixture of
EtOH and CH Cl to give a white solid (0.51 g, 1.1 mmol, 27%
yield). H NMR (500 MHz, C ): δ 1.02 (dd, J = 6.7, 0.5 Hz, 6
3
1
Hz), 160.4. P NMR (121 MHz, CDCl ): δ -6.5. Mp 65-66 °C
3
2
2
1
10
D
6 6
(lit. mp 64.5-65.5 °C).
H), 2.15 (t, J = 7.0 Hz, 2 H), 2.31-2.46 (m, 1 H), 7.01-7.06
(4-Methoxyphenyl)diphenylphosphine Silver Iodide and Silver
Chloride (15 and 16). 15 and 16 were prepared from (4-meth-
oxyphenyl)diphenylphosphine and AgI or AgCl. The product
1
3
(
(
J
J
J
m, 2 H), 7.06-7.12 (m, 4 H), 7.81-7.88 (m, 4 H). C NMR
125 MHz, C
): δ 25.2 (d, J31P-13C = 9.2 Hz), 26.9 (d,
31P-13C = 9.2 Hz), 31.9 (d, J31P-13C = 8.9 Hz), 128.7 (d,
= 9.2 Hz), 129.6 (d, J = 1.5 Hz), 133.9 (d,
6 6
D
CH
H NMR (300 MHz, CD
OC
H
PPh
AgI was isolated as white needles in 80% yield.
Cl ): δ 3.80 (s, 3 H), 6.86-6.93 (m,
3
6
4
2
1
31P-13
31P-13
C
2
2
C
31
31P-13C = 15.3 Hz), 135.3 (d, J31P-13C = 20.1 Hz). P NMR
2 H), 7.31-7.39(m, 4 H), 7.40-7.47 (m, 2 H), 7.54-7.64 (m, 6 H).
13
C NMR (75 MHz, CD
= 28.7 Hz), 129.1 (d, J
Cl
): δ 55.8, 114.8 (d, J P-
31
13 = 10.8
= 9.5 Hz),
(
[
121 MHz, C
(C H PAg) I] 824.9595, found 824.9785.
6
D
6
): δ -15.3. Mp 260-264 °C. HRMS calcd for
2
2
C
þ
Hz), 123.3 (d, J31P-13
31P-13
16
19
2
C
C
Synthesis of Isobutyldiphenylphosphine Silver Chloride
(CH CHCH PPh AgCl) (6). The same procedure used to
prepare 5 was used substituting AgCl (0.72 g, 5.0 mmol) for
(
3
)
2
2
2
(
10) McEwen, W. E.; Shiau, W.-I.; Yeh, Y.-I.; Schulz, D. N.; Pagilagan,
R. U.; Levy, J. B.; Symmes, C. Jr.; Nelson, G. O.; Granoth, I. J. Am. Chem.
Soc. 1975, 97, 1787.
AgI. The product was recrystallized from an EtOH/CH Cl
2
2
J. Org. Chem. Vol. 75, No. 3, 2010 877