Organometallics
Article
3H), 1.68−1.53 (m, 3H). 13C{1H} NMR (100 MHz, CDCl3): δ
160.3, 139.8, 137.9, 135.7, 134.5, 134.3, 133.4, 130.6, 130.4, 129.7,
129.5, 128.4, 126.5, 123.9, 123.5, 123.2, 121.5, 120.4, 65.4, 58.8, 45.9,
42.1, 20.8, 15.9. HRMS (positive ESI): [M − Br−]+ calcd for
1H), 7.23 (d, J = 8.0 Hz, 2H), 7.15 (d, J = 8.3 Hz, 2H), 6.95−6.91
(m, 2H), 6.81 (t, J = 7.8, 1H), 6.26 (d, J = 7. Two Hz, 1H), 4.81−
4.64 (m, 2H), 4.41 (ddd, J = 11.2, 5.3, 3.4 Hz, 1H), 4.08 (dd, J = 11.1,
10.0 Hz, 1H), 3.82 (dd, J = 9.9, 5.4 Hz, 1H), 2.90−2.78 (m, 1H), 2.42
(s, 3H), 1.52 (t, J = 7.3 Hz, 3H), 0.92 (dd, J = 10.6, 7.0 Hz, 6H).
13C{1H} NMR (100 MHz, CDCl3): δ 170.7, 168.7, 160.2, 144.0,
137.58, 137.55, 134.9, 130.2, 126.2, 123.4, 122.0, 119.5, 114.2, 112.0,
66.1, 55.3, 46.1, 30.4, 29.7, 21.2, 18.7, 14.3. HRMS (positive ESI): [M
− Br−]+ calcd for C24H27N4Pd+ 477.1265, found 477.1274. Anal.
Calcd for C24H27N4PdBr: C, 51.68; H, 4.88; N, 10.04. Found: C,
51.63; H, 5.00; N, 9.90.
+
C28H29N4 421.2387, found 421.2390.
(S)-3-Benzyl-1-(3-(4-benzyl-1-(p-tolyl)-4,5-dihydro-1H-imidazol-
2-yl)phenyl)-1H-imidazol-3-ium (3d). Yellow oil. Yield: 64%. [α]D20
=
1
+31.0 (c 0.28, CHCl3). H NMR (400 MHz, CDCl3): δ 11.18 (s,
1H), 8.03−7.99 (m, 1H), 7.74 (s, 1H), 7.63−7.58 (m, 2H), 7.55−
7.49 (m, 1H), 7.47−7.36 (m, 6H), 7.29−7.19 (m, 5H), 6.96 (d, J =
8.0 Hz, 2H), 6.55 (d, J = 8.2 Hz, 2H), 5.84 (s, 2H), 4.61−4.51 (m,
1H), 4.03 (t, J = 9.7 Hz, 1H), 3.74−3.65 (m, 1H), 3.18 (dd, J = 13.7,
4.7 Hz, 1H), 2.86 (dd, J = 13.8, 8.5 Hz, 1H), 2.24 (s, 3H). 13C{1H}
NMR (100 MHz, CDCl3): δ 160.3, 139.7, 137.8, 136.1, 134.6, 134.3,
133.3, 132.9, 130.7, 130.5, 129.8, 129.6, 129.49, 129.48, 129.4, 128.4,
126.5, 123.9, 123.6, 122.8, 121.5, 120.4, 65.3, 58.8, 53.7, 42.1, 20.8.
Pd(II) Complex 4b. Yield: 28%. Mp > 300 °C. [α]2D0 = +187° (c
1
0.04, CHCl3). H NMR (400 MHz, CDCl3): δ 7.54 (d, J = 6.8 Hz,
2H), 7.37−7.29 (m, 3H), 7.26−7.22 (m, 3H), 7.17 (d, J = 8.2 Hz,
2H), 6.93 (d, J = 7.7 Hz, 1H), 6.85−6.77 (m, 2H), 6.28 (d, J = 7.5
Hz, 1H), 6.07 (d, J = 14.3 Hz, 1H), 5.80 (d, J = 14.3 Hz, 1H), 4.43
(ddd, J = 11.1, 5.3, 3.4 Hz, 1H), 4.10 (t, J = 10.6 Hz, 1H), 3.84 (dd, J
= 9.9, 5.4 Hz, 1H), 2.93−2.81 (m, 1H), 2.42 (s, 3H), 0.94 (dd, J =
6.9, 3.9 Hz, 6H). 13C{1H} NMR(100 MHz, CDCl3): 171.0, 168.6,
159.9, 144.2, 137.7, 137.6, 135.1, 130.2, 128.9, 128.8, 128.1, 126.3,
123.3, 122.1, 119.8, 114.6, 111.9, 66.2, 55.4, 53.6, 30.0, 21.2, 18.8,
14.5. HRMS (positive ESI): [M − Br−]+ calcd for C29H29N4Pd+
539.1422, found 539.1429. Anal. Calcd for C29H29N4PdBr: C, 56.19;
H, 4.72; N, 9.04. Found: C, 56.41; H, 4.82; N, 8.74.
+
HRMS (positive ESI): [M − Br−]+ calcd for C33H31N4 483.2543,
found 483.2549
(S)-1-(3-(4-(tert-Butyl)-1-(p-tolyl)-4,5-dihydro-1H-imidazol-2-yl)-
phenyl)-3-ethyl-1H-imidazol-3-ium (3e). Yellow oil. Yield: 72%.
[α]2D0 = +23° (c 0.409, CHCl3). H NMR (400 MHz, CDCl3): δ
1
10.86 (s, 1H), 8.05−7.99 (m, 1H), 7.94 (s, 1H), 7.79 (s, 1H), 7.60−
7.55 (m, 1H), 7.50−7.40 (m, 2H), 7.05−6.97 (m, 2H), 6.76−6.68
(m, 2H), 4.73−4.62 (m, 2H), 4.16−4.06 (m, 1H), 4.03−3.94 (m,
1H), 3.71−3.61 (m, 1H), 2.27 (d, J = 2.0 Hz, 3H), 1.66 (td, J = 7.2,
2.3 Hz, 3H), 0.98 (d, J = 2.3 Hz, 9H). 13C{1H} NMR (100 MHz,
CDCl3): δ 160.0, 140.2, 135.6, 134.3, 134.2, 133.7, 130.6, 130.3,
129.7, 123.7, 123.5, 123.2, 121.4, 120.4, 74.0, 55.8, 45.8, 34.2, 25.9,
20.8, 15.8. HRMS (positive ESI): [M − Br−]+ calcd for C25H31N4
387.2543, found 387.2543.
(S)-3-Benzyl-1-(3-(4-(tert-butyl)-1-(p-tolyl)-4,5-dihydro-1H-imi-
dazol-2-yl)phenyl)-1H-imidazol-3-ium (3f). Yellow oil. Yield: 62%.
[α]2D0 = +83.0 (c 0.25, CHCl3). 1H NMR (400 MHz, CDCl3): δ 10.96
(s, 1H), 7.96 (s, 2H), 7.76 (s, 1H), 7.74−7.68 (m, 2H), 7.54 (s, 1H),
7.52−7.29 (m, 5H), 7.05−6.98 (m, 2H), 6.76−6.69 (m, 2H), 5.87 (s,
2H), 4.16−4.06 (m, 1H), 4.05−3.94 (m, 1H), 3.70−3.62 (m, 1H),
2.29−2.22 (m, 3H), 0.98 (s, 9H). 13C{1H} NMR(100 MHz, CDCl3):
δ 160.0, 140.1, 135.4, 134.29, 134.26, 133.5, 133.2, 130.5, 130.3,
129.8, 129.4, 129.3, 123.7, 123.5, 121.6, 120.5, 73.9, 55.9, 53.3, 34.2,
25.9, 20.8. HRMS (positive ESI): [M − Br−]+ calcd for C30H33N4
449.2700, found 449.2698.
Pd(II) Complex 4c. Yield: 33%. Mp = 257−258 °C. [α]2D0 = +149°
(c 0.11, CHCl3). 1H NMR (400 MHz, CDCl3): δ 7.40 (d, J = 6.3 Hz,
2H), 7.33 (d, J = 1.9 Hz, 1H), 7.24−7.17 (m, 4H), 7.14 (d, J = 8.2
Hz, 2H), 6.99−6.93 (m, 2H), 6.78 (t, J = 7.8 Hz, 2H), 6.12 (d, J = 7.7
Hz, 1H), 4.83−4.68 (m, 3H), 4.09 (t, J = 10.2 Hz, 1H), 3.80 (dd, J =
9.9, 4.0 Hz, 1H), 3.40 (dd, J = 13.4, 3.4 Hz, 1H), 3.17 (dd, J = 13.4,
7.6 Hz, 1H), 2.37 (s, 3H), 1.54 (t, J = 7.2 Hz, 3H). 13C{1H} NMR
(100 MHz, CDCl3): δ 170.8, 168.9, 160.1, 144.2, 137.66, 137.61,
137.1, 135.0, 130.2, 130.0, 128.1, 126.3, 126.2, 123.2, 121.9, 119.4,
114.4, 111.9, 62.1, 59.0, 45.4, 40.1, 29.7, 21.1. HRMS (positive ESI):
[M − Br−]+ calcd for C28H27N4Pd+ 525.1265, found 525.1281. Anal.
Calcd for C28H27N4PdBr: C, 55.51; H, 4.49; N, 9.25. Found: C,
55.89; H, 4.58; N, 9.09.
Pd(II) Complex 4d. Yield: 30%. Mp > 300 °C. [α]2D0 = +239° (c
1
0.04, CHCl3). H NMR (400 MHz, CDCl3): δ 7.56 (d, J = 6.8 Hz,
2H), 7.43 (d, J = 6.6 Hz, 2H), 7.39−7.29 (m, 3H), 7.28 (d, J = 1.9
Hz, 1H), 7.25−7.17 (m, 4H), 7.15 (d, J = 8.0 Hz, 2H), 6.94 (t, J = 7.5
Hz, 1H), 6.89−6.74 (m, 3H), 6.17−6.10 (m, 2H), 5.90 (d, J = 14.3
Hz, 1H), 4.82−4.69 (m, 1H), 4.12 (t, J = 10.1 Hz, 1H), 3.83 (dd, J =
9.9, 3.9 Hz, 1H), 3.43 (dd, J = 13.4, 3.5 Hz, 1H), 3.20 (dd, J = 13.3,
7.6 Hz, 1H), 2.38 (s, 3H). 13C{1H} NMR (100 MHz, CDCl3): δ
171.2, 169.2, 160.5, 144.0, 137.7, 137.6, 137.0, 136.5, 135.0, 130.2,
130.1, 128.8, 128.2, 128.1, 126.3, 123.4, 123.3, 122.0, 119.8, 114.7,
112.1, 62.3, 58.9, 54.4, 41.1, 21.2. HR-MS (positive ESI): [M − Br−]+
calcd for C33H29N4Pd+ 587.1422, found 587.1430. Anal. Calcd for
C33H29N4PdBr: C, 59.34; H, 4.38; N, 8.39. Found: C, 59.72; H, 4.51;
N, 8.17.
1-(3-((4S,5S)-4,5-Diphenyl-1-(p-tolyl)-4,5-dihydro-1H-imidazol-
2-yl)phenyl)-3-ethyl-1H-imidazol-3-ium (3g). Yellow oil. Yield: 63%.
[α]2D0 = +59.0 (c 0.27, CHCl3). 1H NMR (400 MHz, CDCl3): δ 11.03
(s, 1H), 7.95 (d, J = 8.0 Hz, 1H), 7.90 (s, 1H), 7.66 (s, 1H), 7.58−
7.51 (m, 3H), 7.38 (t, J = 8.0 Hz, 1H), 7.28−7.19 (m, 6H), 7.17−
7.10 (m, 4H), 6.98 (d, J = 8.2 Hz, 2H), 5.05 (d, J = 7.3 Hz, 1H), 4.66
(d, J = 7.3 Hz, 1H), 4.68 (q, J = 7.3 Hz, 2H), 2.35 (s, 3H), 1.66 (t, J =
7.3 Hz, 3H). 13C{1H} NMR (100 MHz, CDCl3): δ 161.6, 142.8,
142.6, 140.0, 136.2, 135.7, 134.5, 133.3, 130.8, 130.7, 130.0, 129.1,
128.9, 128.1, 127.7, 126.8, 126.6, 124.8, 124.3, 122.4, 121.9, 120.5,
79.2, 78.6, 45.9, 20.8, 15.7. HRMS (positive ESI): [M − Br−]+ calcd
Pd(II) Complex 4e. Yield: 33%. Mp = 191−192 °C. [α]2D0 = +177°
+
1
for C33H31N4 483.2543, found 483.2544.
(c 0.10, CHCl3). H NMR (400 MHz, CDCl3): δ 7.33 (s, 1H), 7.23
General Procedure for the Synthesis of Pd(II) Complexes
4a−g. In a 25 mL two-necked Schlenk tube were placed 3 (0.44
mmol), NaOAc (0.36 g, 4.40 mmol), and Pd(OAc)2 (0.12 g, 0.53
mmol) in dry DMAc (10 mL). The mixture was refluxed under an Ar
atmosphere for 48 h. After the mixture was cooled and concentrated
in vacuo, the residue was purified by passing through a short column
containing a layer of Celite and a layer of silica with dichloromethane
as eluent. The solvent was removed under reduced pressure, and a
solution of lithium bromide (467 mg, 5.38 mmol) in acetone/water
(3/2, 50 mL) was added. The resulting solution was stirred at room
temperature for 48 h and extracted with dichloromethane. The
organic layer was washed with brine, dried over MgSO4, and
evaporated. The final products 4 were purified once again by
preparative TLC on silica gel plates with CH2Cl2/EtOAc 10/1 as
eluent.
(d, J = 8.0 Hz, 2H), 7.13 (d, J = 7.7 Hz, 2H), 6.99−6.90 (m, 2H),
6.84−6.77 (m, 1H), 6.29 (d, J = 7.8 Hz, 1H), 4.84−4.64 (m, 2H),
4.15−4.05 (m, 2H), 3.98−3.89 (m, 1H), 2.41 (s, 3H), 1.50 (t, J = 7.2
Hz, 3H), 1.10 (s, 9H). 13C{1H} NMR (100 MHz, CDCl3): δ 169.5,
168.8, 158.9, 144.1, 137.6, 137.5, 134.8, 130.2, 126.2, 123.3, 122.0,
119.5, 114.4, 112.0, 68.6, 58.0, 45.3, 35.7, 26.4, 21.2, 16.9. HRMS
(positive ESI): [M − Br−]+ calcd for C25H29N4Pd+ 491.1422, found
491.1430. Anal. Calcd for C25H29N4PdBr: C, 52.51; H, 5.11; N, 9.80.
Found: C, 52.75; H, 5.38; N, 9.62.
Pd(II) Complex 4f. Yield: 24%. Mp > 300 °C. [α]2D0 = +168° (c
1
0.10, CHCl3). H NMR (400 MHz, CDCl3): δ 7.51 (d, J = 6.8 Hz,
2H), 7.36−7.22 (m, 6H), 7.15 (d, J = 7.8 Hz, 2H), 6.93 (d, J = 7.7
Hz, 1H), 6.85−6.75 (m, 2H), 6.30 (d, J = 7.8 Hz, 1H), 6.09 (d, J =
14.4 Hz, 1H), 5.83 (d, J = 14.4 Hz, 1H), 4.18−4.07 (m, 2H), 3.95 (d,
J = 7.7 Hz, 1H), 2.42 (s, 3H), 1.12 (s, 9H). 13C{1H} NMR (100
MHz, CDCl3): δ 170.1, 168.9, 159.0, 144.1, 137.7, 137.5, 136.6,
134.9, 130.2, 128.8, 128.8, 128.1, 126.3, 123.4, 122.1, 119.9, 114.7,
Pd(II) Complex 4a. Yield: 32%. Mp = 258−259 °C. [α]2D0 = +123°
(c 0.06, CHCl3). 1H NMR (400 MHz, CDCl3): δ 7.29 (d, J = 2.0 Hz,
F
Organometallics XXXX, XXX, XXX−XXX