Organometallics
Article
+
4
4
1
1
1
H), 4.36 (t, J = 6.9 Hz, 4H), 3.69−3.56 (m, 4H), 2.23−2.08 (m,
C H ClN PdP F [M + 2PF ] : 1370.1789. Found: 1370.1763
63 53 5 4 12 6
[M + 2PF6]
H). 13C { H} NMR (101 MHz, DMSO-d ) δ 154.3, 139.6, 137.6,
1
+
6
35.7 (d, J = 3.1 Hz), 134.1 (d, J = 10.2 Hz), 130.9 (d, J = 12.5 Hz),
23.8, 123.0, 122.5, 118.9, 118.0, 53.4, 49.3 (d, J = 21.2 Hz), 23.1,
Proligand 6. [3,3′-(Pyridine-2,6-diylbis(methylene))bis(1-(3-
(triphenylphosphonio)benzyl)-1H-imidazol-3-ium)] [PF ] [Br] .
6
2
2
8.6. 31P { H} NMR (162 MHz, DMSO-d ) δ 23.93, −144.20 (m).
1
[(3-((1H-Imidazol-1-yl)methyl)phenyl)triphenylphosph nium][PF6]
(6.3) (0.43 g, 0.75 mmol) was weighed into a flame-dried round-
bottomed flask along with 0.090 g (0.34 mmol) of 2,6-bis-
(bromomethylpyridine), and the solids were dissolved in 3 mL of
CH CN. The solution was brought to reflux under N for 12 h. The
reaction was cooled to room temperature, and the solution was
reduced to half the original volume in vacuo and then dry Et O added
6
+
HR ESI-MS: Calcd for [M + 3PF ] ,C H N F P : 1282.2858.
Found: 1282.2869 [M + 3PF ]+
6
55 55
5 18 5
6
Complex 4. Metalation of proligand 4 was carried out according to
the general metalation procedure with 0.27 g (0.21 mmol) of
proligand 4. The relative amount of solvent and reagents added was
scaled according to the molar ratios provided in the general method.
Following the general workup, the crude was dissolved in 2 mL of
DCM and washed twice with water and twice with brine and dried
3
2
2
to double the volume, resulting in a light white precipitate. This was
collected by centrifugation, redissolved in CH CN, and precipitated a
3
over MgSO . Evaporation of the solvent afforded 0.16 g (55%) of
second time with Et O. The solids were isolated by centrifugation and
dried to isolate a white solid (0.47 g, 97%). H NMR (400 MHz,
4
2
1
1
light yellow solid. H NMR (400 MHz, CD CN) δ 8.06 (td, J = 7.8,
3
1
2
1
1
.5 Hz, 1H), 7.81 (ddd, J = 9.1, 5.2, 1.8 Hz, 6H), 7.75−7.59 (m,
8H), 7.34 (t, J = 1.7 Hz, 2H), 7.13 (d, J = 1.7 Hz, 2H), 5.22 (dd, J =
5.3, 1.5 Hz, 2H), 4.89 (dd, J = 14.8, 9.7 Hz, 4H), 4.34 (ddt, J = 16.8,
2.3, 6.2 Hz, 2H), 3.24 (qd, J = 16.1, 14.4, 7.1 Hz, 4H), 2.70−2.45
DMSO-d ) δ 9.55 (d, J = 1.9 Hz, 2H), 8.03−7.96 (m, 9H), 7.92−7.80
6
(m, 20H), 7.80−7.72 (m, 14H), 7.49 (d, J = 7.8 Hz, 2H), 5.72 (s,
1
3
1
4H), 5.60 (s, 4H). C{ H} NMR (101 MHz, DMSO-d ) δ 154.1,
6
139.5, 136.0 (d, J = 3.2 Hz), 135.4, 135.3, 135.1 (d, J = 10.6 Hz),
134.4 (d, J = 11.0 Hz), 131.7 (d, J = 13.2 Hz), 131.0 (d, J = 12.8 Hz),
1
3
1
(
m, 3H), 2.17 (d, J = 1.5 Hz, 9H). C{ H} NMR (101 MHz,
3
1
1
CD CN) δ 164.5, 155.1, 135.2, 135.2, 133.8, 133.7, 130.3, 130.2,
124.2, 123.0, 122.7, 119.6, 118.7, 118.3, 117.4, 53.4, 51.6. P { H}
3
3
1
1
1
25.6, 122.6, 121.5, 118.1, 55.1, 24.9. P { H} NMR (162 MHz,
NMR (162 MHz, DMSO-d ) δ 22.30, −144.20 (m). HR ESI-MS:
6
+
DMSO-d ) δ 23.92, −144.19 (m). HR ESI-MS: Calcd for
C H ClN PdP F [M + 2PF ] : 1274.1789. Found: 1274.1792
Calcd for C H N P F [M + 3PF ] : 1378.2858. Found: 1378.2861
6
63 55
[M + 3PF ]
5
5
18
6
+
+
55
53
5
4
12
6
6
+
[
M + 2PF6]
Complex 6. The synthesis of complex 6 was carried out according
to the general metalation procedure beginning with 0.43 g (0.31
mmol) of proligand 6. All other reagents were added according to the
molar ratios described above and the volume of DMSO added was
scaled to keep molarities consistent. Following the general workup,
the crude was purified by column chromatography over basic alumina
Proligand 5. [2,2′-(Pyridine-2,6-diylbis(methylene))bis(1-(3-
(
triphenylphosphonio)benzyl)-1H-imidazol-3-ium)] [PF ] [Br] .
6
2
2
17
This procedure was modified from the literature. ([(2-((1H-
Imidazol-1-yl)methyl)phenyl)triphenylphosphonium][PF ] (5.3)
6
(
1.00 g, 1.77 mmol) was weighed into a flame-dried round-bottomed
flask along with 2,6-bis-(bromomethylpyridine) (0.19 g, 0.71 mmol).
The solids were dissolved in 3 mL of CH CN, and the solution was
with DCM/MeOH (90:10) as the eluant. Solvent removal produced
1
an off-white solid (0.20 g, 42%). H NMR (400 MHz, DMSO-d
) δ
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6
brought to reflux under N for 12 h. The reaction was brought to RT,
and the precipitates formed during the course of the reaction were
separated from the reaction mixture by centrifugation. The isolated
8.26−8.18 (m, 1H), 7.94 (t, J = 7.2 Hz, 10H), 7.89−7.61 (m, 32H),
7.59 (d, J = 2.1 Hz, 2H), 7.44 (d, J = 13.4 Hz, 2H), 7.36 (d, J = 2.2
Hz, 2H), 5.83 (d, J = 15.3 Hz, 2H), 5.68 (d, J = 15.4 Hz, 2H), 5.61
2
1
3
1
solids were ground three times under Et O to remove most of the
(d, J = 15.1 Hz, 2H), 5.42 (d, J = 15.0 Hz, 2H). C { H} NMR (101
MHz, DMSO-d ) δ 165.2, 155.5, 142.5, 140.4 (d, J = 12.7 Hz),
135.86, 134.93 (d, J = 10.5 Hz), 134.42, 133.58 130.9 (d, J = 12.8
2
starting material. Finally, the washed crude product was dissolved in a
minimal volume of CH CN and dropped into Et O to yield a
6
3
2
3
1
1
precipitate that was isolated by centrifugation. This process was
repeated four times to obtain the bis-substituted proligand in
Hz), 126.2, 123.1, 118.8, 118.3, 117.9, 117.5, 54.9, 51.9. P { H}
NMR (162 MHz, DMSO-d ) δ 22.32, −144.21 (m). HR ESI-MS:
Calcd for C63 +PdP
1370.1789 [M + 2PF
6
1
+
acceptable purity. Yield: 0.94 g (0.68 mmol, 95%). H NMR (400
H
53ClN
5
F12 [M + 2PF ] : 1370.1789. Found:
4 6
MHz, DMSO-d ) δ 8.12 (tt, J = 7.7, 1.6 Hz, 2H), 8.00 (d, J = 7.8 Hz,
6
]
6
1
7
=
H), 7.97−7.92 (m, 4H), 7.89 (tdd, J = 7.7, 2.5, 1.2 Hz, 3H), 7.85−
Proligand 7. [3,3′-(((Pyridine-2,6-diylbis(methylene))bis(1H-imi-
.75 (m, 25H), 7.69 (t, J = 1.8 Hz, 2H), 7.44−7.35 (m, 4H), 7.21 (t, J
dazole-3-ium-1,3-diyl))bis(methylene))bis(1-methylpyridin-1-ium)]
1
3
1
−
−
1.9 Hz, 2H), 5.49 (s, 4H), 5.19 (s, 4H). C { H} NMR (101 MHz,
(Figure S1) (0.54 g, 1.99 mmol) was combined with 0.22 g (0.91
mmol) of BIP in a flame-dried round-bottomed flask. Dry CH CN
was added (25 mL), and the insoluble mixture was stirred vigorously
and heated to reflux under N . Complete dissolution of the solids was
] [Br ] . ([3-(Chloromethyl)-1-methylpyridin-1-ium][I] (4.2)
DMSO-d ) δ 154.1, 139.6, 137.9 (d, J = 7.4 Hz), 137.7, 137.6, 137.0,
6
1
1
1
36.1 (d, J = 3.2 Hz), 135.0 (d, J = 10.7 Hz), 133.8 (d, J = 9.5 Hz),
3
31.7 (d, J = 12.4 Hz), 131.2 (d, J = 12.8 Hz), 123.8, 122.8, 122.7,
3
1
1
18.1, 117.8, 117.2, 116.9, 53.4, 51.3. P { H} NMR (162 MHz,
2
DMSO-d ) δ 21.35, −144.21 (m). HR ESI-MS: Calcd for
observed at this point. The reaction was allowed to stir under reflux
overnight to produce a blue-green precipitate. The solids were
isolated, taken up into a small amount of methanol and dropped into
6
+
C H N P F [M + 3PF ] : 1378.2858. Found: 1378.2871 [M +
6
3
55
5
5
18
6
+
3
PF6]
Complex 5. Proligand 5 was metalated according to the general
a saturated aqueous solution of KPF to render a precipitate that was
6
metalation procedure using 0.64 g (0.46 mmol) of proligand 5.
Molarity and molar ratio of added reagents were held to the general
metalation procedure. Following the general workup, the crude was
taken up into DCM, washed twice with water and twice with brine
collected and washed with water. The product was purified by
recrystallization from a boiling mixture of acetone and MeOH to
1
produce a crystalline white powder (0.36 g, 38%). H NMR (400
MHz, DMSO-d ) δ 9.37 (t, J = 1.6 Hz, 2H), 9.09 (d, J = 1.5 Hz, 2H),
6
and dried over MgSO . The product was purified further by
9.06 (dd, J = 6.1, 1.3 Hz, 2H), 8.60 (dt, J = 8.2, 1.5 Hz, 2H), 8.24 (dd,
J = 8.1, 6.1 Hz, 2H), 8.01 (t, J = 7.8 Hz, 1H), 7.84 (d, J = 1.6 Hz, 4H),
7.47 (d, J = 7.8 Hz, 2H), 5.70 (s, 4H), 5.58 (s, 4H), 4.38 (s, 6H).
4
recrystallizing from a minimum amount of DCM at −12 °C to
1
yield an off-white crystalline powder (0.29 g, 42%). H NMR (400
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3
1
MHz, DMSO-d ) δ 8.22 (t, J = 7.7 Hz, 1H), 8.03 (t, J = 7.8 Hz, 2H),
C{ H} NMR (101 MHz, DMSO-d ) δ 154.10, 146.18, 145.96,
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6
7
7
2
1
1
1
.95−7.88 (m, 7H), 7.87−7.72 (m, 27H), 7.61 (d, J = 1.9 Hz, 2H),
.39−7.29 (m, 2H), 7.24 (dd, J = 7.7, 5.8 Hz, 2H), 6.86−6.79 (m,
H), 5.63 (d, J = 15.2 Hz, 2H), 5.42 (d, J = 15.1 Hz, 2H), 5.26 (d, J =
145.35, 139.62, 138.22, 135.11, 128.33, 124.24, 123.17, 122.72, 53.60,
+
48.98, 48.72. HR ESI-MS: Calcd for C H N P F [M + 3PF ] :
2
7
31
7
3
18
6
+
888.1566. Found: 888.1556 [M + 3PF6]
1
3
1
6.0 Hz, 2H), 5.03 (s, 2H). C { H} NMR (101 MHz, DMSO-d ) δ
Complex 7. Metalation of proligand 7 was carried out according to
the general metalation procedure with 0.35 g (0.34 mmol) of 7.
Following the general workup, the crude was purified by column
chromatography over neutral alumina with 1% saturated KNO3
(aqueous) in acetonitrile as the eluant. The isolated solids were
taken up into acetonitrile and dropped into saturated KPF6
6
66.2, 155.3, 142.4, 142.0 (d, J = 7.5 Hz), 137.0 (d, J = 11.5 Hz),
36.5, 135.9 (d, J = 3.0 Hz), 134.9 (d, J = 10.6 Hz), 131.3 (d, J = 12.8
Hz), 131.0 (d, J = 9.9 Hz), 130.3 (d, J = 12.7 Hz), 126.3, 123.6, 122.0,
3
1
1
1
18.3, 117.4, 116.3, 115.5, 55.0, 52.0. P { H} NMR (162 MHz,
DMSO-d ) δ 21.09, −144.20 (m). HR ESI-MS: Calcd for
6
L
Organometallics XXXX, XXX, XXX−XXX