W. Sikorski et al. / Journal of Organometallic Chemistry 867 (2018) 323e332
325
JHH ¼ 2.0 Hz), 6.87 (d, 1H, NCH, JHH ¼ 2.0 Hz), 6.75 (d, 1H, NCH,
JHH ¼ 1.65 Hz), 5.02 (s, 2H, NCH2), 4.52 (t, 2H, NCH2, JHH ¼ 7.65 Hz),
4.12 (s, 3H, NCH3), 2.76 (s, 3H, CCH3) 2.11 (mult, 2H, CH2),1.49 (mult,
2H, CH2), 1.04 (t, 3H, CH3, JHH ¼ 7.40 Hz).
6.85 (d, 1H, NCH, JHH ¼ 2.0 Hz), 6.81 (pseudo t, 1H, NCH), 6.67 (d, 1H,
NCH, JHH ¼ 2.0 Hz), 5.82 (s, 2H, NCH2), 4.17 (s, 3H, NCH3), 3.68 (s, 3H,
NCH3).
13C NMR (125.7 MHz, CDCl3,
d [ppm]): 151.5 (NCN), 138.7
13C NMR (125.7 MHz, CDCl3,
d
[ppm]): 150.9 (NCN), 145.8 (NCN),
(NCHN), 135.7 (Ar), 129.0 (Ar), 129.1 (Ar), 128.6 (Ar), 128.5 (NCH),
123.4 (NCH), 121.1 (NCH), 119.8 (NCH), 54.7 (NCH2), 38.1 (NCH3),
34.4 (NCH3).
135.1 (NCH), 129.3 (Ar), 128.5 (Ar), 128.3 (Ar), 127.1 (Ar), 122.8
(NCH), 121.6 (NCH), 120.0 (NCH), 50.6 (NCH2), 51.1 (NCH2), 38.5
(NCH3), 32.4 (CH2), 20.1 (CH2), 14.8 (CCH3), 13.9 (CH3).
2.3.3. [PdCl2(miop-y)(1-methylimidazole)] (2c): yield 48%. Anal.
calcd. (%) For C12H20N4OCl2Pd: C 34.84; H 4.87; N 13.55. Found: C
35.01; H 4.78; N 13.45
2.2.7. [PdI2(bmim-y)(1-benzyl-2-methylimidazole)] (1g): yield:
82%, Anal. calcd. (%) For C19H26N4I2Pd: 34.03; H 3.91; N 8.35. found:
C 33.65; H 3.65; N 8.35
1H NMR (500 MHz, CDCl3,
d [ppm]): 8.05 (broad s,1H, NCH), 7.50
1H NMR (500 MHz, CDCl3,
d
[ppm]): 7.34 (mult, 3H, Ar), 7.11 (d,
(pseudo t,1H, NCH), 7.12 (d,1H, NCH, JHH ¼ 2.0 Hz), 6.94 (d,1H, NCH,
JHH ¼ 2.0 Hz), 6.81 (pseudo t, 1H, NCH), 5.97 (s, 2H, NCH2O), 4.16 (s,
3H, NCH3), 3.68 (s, 3H, NCH3), 3.67 (t, 2H, OCH2, JHH ¼ 6.55 Hz), 1.62
(mult, 2H, CH2), 0.91 (t, 3H, CH3, JHH ¼ 7.40 Hz).
1H, NCH, JHH ¼ 1.60 Hz), 7.06 (mult, 2H, Ar), 6.90 (s, 2H, 2 x NCH),
6.77 (d, 1H, NCH, JHH ¼ 1.60 Hz), 5.04 (s, 2H, NCH2), 4.41 (t, 2H,
NCH2, JHH ¼ 7.75 Hz), 3.99 (s, 3H, NCH3), 2.69 (s, 3H, CCH3), 2.06
(mult, 2H, CH2), 1.48 (mult, 2H, CH2), 1.03 (t, 3H, CH3, JHH ¼ 7.40 Hz).
13C NMR (125.7 MHz, CDCl3,
d [ppm]): 151.6 (NCN), 138.7
13C NMR (125.7 MHz, CDCl3,
d
[ppm]): 149.2 (NCN), 145.6 (NCN),
(NCHN), 128.6 (NCH), 120.4 (NCH), 119.9 (NCH), 123.8 (NCH), 80.1
(NCH2O), 71.4 (OCH2), 38.2 (NCH3), 34.4 (NCH3), 22.8 (CH2), 10.6
(CH3).
135.1 (NCH), 128.7 (Ar), 128.5 (Ar), 126.9 (Ar), 123.3 (Ar), 123.1
(NCH), 121.5 (NCH), 120.2 (NCH), 51.5 (NCH2), 50.6 (NCH2), 39.2
(NCH3), 31.6 (CH2), 20.2 (CH2), 15.7 (CCH3), 13.9 (CH3).
2.3.4. [PdCl2(bnmbenzim-y)(1-methylimidazole)] (2d): yield 63%.
Anal. calcd. (%) For C19H20N4Cl2Pd: C 47.34; H 4.19; N 11.63; found: C
47.67; H4.15; N 11.18
2.3. Synthesis of palladium PEPPSI-type complexes with different
carbene ligands [PdCl2(NHC)(imidazole)]. Method B
1H NMR (500 MHz, CD2Cl2,
d [ppm]): 8.09 (broad s, 1H, NCHN),
Palladium (II) complex with 1-methylimidazole ligands
[PdCl2(1-methylimidazole)2] (0.5 mmol, 0.17 g), K2CO3 (1.5 mmol,
0.21 g), MgSO4 (0.2 g, for drying), an appropriate imidazolium
chloride (0.65 mmol) and finally a mixture of solvents CH3CN:THF
(8 ml: 5 ml) were placed in a round-bottom flask equipped with a
stirring bar. The flask was capped with a rubber septum. The
mixture was heated in the oil bath for 24 h at 50 ꢀC in the air at-
mosphere. During that time, the color changed from yellow to
greenish. After the reaction, the cooled down mixture was filtrated
to remove inorganic salts. Then, the yellow solution was evaporated
under vacuum and the resulting oily residue was dissolved in a
minimum amount of acetone. Next, 10 ml of water was slowly
added to the yellow solution and clouding of the mixture was
observed. The mixture was left to evaporate acetone and to enable
sedimentation of the formed precipitate. After that time, water
with excess of the imidazolium chloride and 1-methylimidazole
was decanted. The obtained product was washed with the water
and dried under vacuum. The complexes 2f and 2 g were obtained
from the appropriate imidazole and the precipitated solids required
additional washing with ethyl alcohol and diethyl ether. One of the
obtained complexes [PdCl2(IMes)(1-methylimidazole)] (2e) was
described in the literature [7b].
7.57 (mult, 2H, Ar), 7.50 (pseudo t, 1H, NCH), 7.27e7.37 (mult, 4H,
Ar), 7.44 (mult, 1H Ar), 7.16 (mult, 2H, Ar), 6.89 (pseudo t, 1H, NCH),
6.17 (s, 2H, NCH2Ph), 4.40 (s, 3H, NCH3), 3.70 (s, 3H, NCH3).
13C NMR (125.7 MHz, CDCl3,
d [ppm]): 165.8 (NCN), 138.7
(NCHN), 135.7 (Ar), 135.3 (Ar), 134.1 (Ar), 128.5 (Ar), 128.2 (Ar) 128.1
(Ar), 123.3 (NCH), 123.2 (Ar), 119.9 (NCH), 111.5 (Ar), 110.1 (Ar), 53.1
(NCH2Ph), 34.9 (NCH3), 34.4 (NCH3).
2.3.5. [PdCl2(IMes)(1-methylimidazole)] (2e): yield 55%. Anal. calcd.
(%) For C25H30N4Cl2Pd: C 53.25; H 5.36; N 9.94. found: C 52.52; H
5.48; N 9.43
1H NMR (500 MHz, CD2Cl2,
d [ppm]): 7.78 (s, 1H, NCHN), 7.23
(pseudo t, 1H, NCH), 7.03 (s, 2H, NCH), 7.02 (s, 4H, Ar), 6.56 (pseudo
t, 1H, NCH), 3.48 (s, 3H, NCH3), 2.36 (s, 12H, ArCH3), 2.35 (s, 6H,
ArCH3).
13C NMR (125.7 MHz, CDCl3,
d [ppm]): 154.1 (NCN), 139.1 (Ar),
138.6 (NCHN), 136.5 (Ar), 135.4 (Ar), 129.3 (Ar), 124.1 (NCH), 128.7
(NCH), 119.0 (NCH), 34.1 (NCH3), 21.3 (ArCH3), 19.3 (ArCH3).
2.3.6. [PdCl2(bmim-y)(1-benzylimidazole)] (2f): yield 40%. Anal.
calcd. (%) For C18H24N4Cl2Pd: C 45.64; H 5.11; N 11.83. Found: C
45.99; H 4.89; N 11.81
1H NMR (500 MHz, CDCl3,
d [ppm]): 8.19 (broad s, 1H, NCHN),
2.3.1. [PdCl2(bmim-y)(1-methylimidazole)] (2a): yield 45%. Anal.
calcd. (%) For C12H20N4Cl2Pd: C 36.25; H 5.07; N 14.09. Found: C
36.77; H 5.16; N 14.65
7.55 (pseudo t, NCH,1H), 7.36 (mult, 3H, Ar), 7.18 (mult, 2H, Ar), 6.88
(d, NCH, 1H, JHH ¼ 1.95 Hz), 6.87 (d, NCH, 1H, JHH ¼ 1.95 Hz), 6.80
(pseudo t, 1H, NCH), 5.07 (s, 2H, NCH2), 4.53 (t, 2H, NCH2,
JHH ¼ 7.65 Hz), 4.14 (s, 3H, NCH3), 2.03 (mult, 2H, CH2), 1.46 (mult,
2H, CH2), 1.00 (t, 3H, CH3).
1H NMR (500 MHz, CDCl3,
d [ppm]): 8.15 (broad s, 1H, NCHN),
7.50 (pseudo t, 1H, NCH), 6.88 (d, 1H, NCH, JHH ¼ 2.0 Hz), 6.86 (d, 1H,
NCH, JHH ¼ 2.0 Hz), 6.80 (pseudo t, 1H, NCH), 4.52 (t, 2H, NCH2,
JHH ¼ 7.55 Hz), 4.13 (s, 3H, NCH3), 3.67 (s, 3H, NCH3), 2.03 (mult, 2H,
CH2), 1.45 (mult, 2H, CH2), 1.00 (t, 3H, CH3, JHH ¼ 7.40 Hz).
13C NMR (125.7 MHz, CDCl3,
d [ppm]): 150.4 (NCN), 138.3
(NCHN), 134.9 (NCH), 129.3 (Ar), 128.8 (Ar), 128.8 (Ar), 127.8 (Ar),
122.8 (NCH), 121.4 (NCH), 118.9 (NCH), 51.9 (CH2), 50.8 (NCH2), 38.0
(NCH3), 32.8 (CH2), 20.1 (CH2), 13.9 (CH3).
13C NMR (125.7 MHz, CDCl3,
d [ppm]): 150.4 (NCN), 138.6
(NCHN), 128.5 (NCH), 122.7 (NCH), 121.3 (NCH), 119.7 (NCH), 50.6
(NCH2), 37.9 (NCH3), 34.2 (NCH3), 32.7 (CH2), 19.9 (CH2), 13.8 (CH3).
2.3.7. [PdCl2(bmim-y)(1-benzyl-2-methylimidazole)] (2g): yield
40%. Anal. calcd. (%) For C19H26N4Cl2Pd: C 46.79; H 5.37; N 11.49.
Found: C 45.94; H 4.60; N 11.07
2.3.2. [PdCl2(bnmim-y)(1-methylimidazole)] (2b): yield 55%. Anal.
calcd. (%) For C15H18N4Cl2Pd: C 41.74; H 4.20; N 12.98. Found: C
40.98; H 3.73; N 12.63
1H NMR (500 MHz, CDCl3,
d [ppm]): 7.34 (mult, 2H, Ar), 7.17 (d,
1H, NCH, JHH ¼ 1.65 Hz), 7.08 (mult, 2H, Ar), 6.86 (d, 1H, NCH,
JHH ¼ 2.0 Hz), 6.85 (d, 1H, NCH, JHH ¼ 2.0 Hz), 6.74 (d, 1H, NCH,
JHH ¼ 1.65 Hz), 5.00 (s, 2H, NCH2), 4.57 (t, 2H, NCH2, JHH ¼ 2.0 Hz),
1H NMR (500 MHz, CDCl3,
d
[ppm]): 8.07 (broad s, 1H, NCHN),
7.52 (pseudo t, 1H, NCH), 7.48 (mult, 2H, Ar), 7.34 (mult, 3H, Ar),