4
T. Yagyu et al. / Journal of Organometallic Chemistry 767 (2014) 1e5
d under Ar. The solvent was removed, and CH2Cl2 and alkaline EDTA
solution were added to the residue. The reaction mixture was
further extracted with CH2Cl2. The combined organic phases were
dried over magnesium sulfate. The solvent was removed to afford
the yellow residue, which was purified by column chromatography
on silica gel (CH2Cl2) and alumina (CH2Cl2) (1.04 g, 3.51 mmol, 82%).
Preparation of dichloro(1-methyl-10-phenyl-3,30-
methylenediimidazolin-2,20-diylidene)palladium(II) (4a)
A mixture of 3a (0.514 g, 0.969 mmol), PdCl2(NCCH3)2 (0.246 g,
0.948 mmol), and NEt3 (0.251 g, 2.48 mmol) in DMSO (4 mL) was
stirred at 60 ꢀC for 2 h and then at 80 ꢀC for 7 h. The resulting
precipitates were filtered, washed with acetone, and dried under
vacuum (0.269 g, 0.647 mmol, 68%). Anal. Calcd for C14H14Cl2N4Pd:
C, 40.46; H, 3.40; N, 13.48. Found: C, 40.33; H, 3.31; N, 13.30. 1H
1H NMR (400 MHz, DMSO-d6):
d
¼ 7.15 (dd, 1H, H4 or H5, 0.8 and
00
00
1.3 Hz), 7.44 (t, 2H, H4 , 7.3 Hz), 7.53 (dd, 4H, H3 , 7.3 and 7.6 Hz), 7.9
0
0
00
(m, 7H, H2 , H4 , and H2 ), 8.02 (dd, 1H, H4 or H5, 1.3 and 1.3 Hz), 8.51
(dd, 1H, H2, 0.8 and 1.3 Hz).
NMR (400 MHz, addition of LiCl, DMSO-d6):
d
¼ 4.01 (s, 3H, Me),
6.34 (d, 1H, eCH2e, 13 Hz), 6.54 (d, 1H, eCH2e, 13 Hz), 7.43 (m, 2H,
00
00
H4 or H5, and H4 ), 7.51 (dd, 2H, H3 ), 7.69e7.76 (m, 4H, H4 or H5,
Preparation of 1-methyl-10-phenyl-3,30-methylenediimidazolium
hexafluorophosphate (3a)
00
0
0
0
0
H2 , H4 or H5 ), 7.86 (s, 1H, H4 or H5 ).
Preparation of dichloro(1-methyl-10-(400-methoxyphenyl)-3,30-
A mixture of 1 (0.653 g, 3.09 mmol) and N-phenylimidazole
(1.03 g, 7.14 mmol) in CH3CN (3 mL) was stirred at 90 ꢀC for 5 d in a
sealed tube. The resulting precipitates were filtered, washed with
acetone, and dried under vacuum to yield dihalide salt 2a (1.03 g) as
a white powder. To an aqueous solution of 2a (1.97 g), we added an
aqueous solution of NH4PF6 (1.83 g, 11.2 mmol). The resulting
precipitates were filtered, washed with water, and dried under
vacuum to result in a white powder (1.94 g, 3.66 mmol). Anal. Calcd
for C14H16F12N4P2: C, 31.71; H, 3.04; N, 10.57. Found: C, 31.77; H,
2.84; N, 10.31. 1H NMR (400 MHz, DMSO-d6): 3.92 (s, 3H, Me), 6.69
methylenediimidazolin-2,20-diylidene)palladium(II) (4b)
A mixture of 3b (0.996 g, 1.78 mmol), PdCl2(NCCH3)2 (0.453 g,
1.75 mmol), and NEt3 (0.434 g, 4.29 mmol) in DMSO (7 mL) was
stirred at rt for 4 h, 60 ꢀC overnight, and 80 ꢀC for 3 h. The resulting
precipitates were filtered, washed with acetone, and dried under
vacuum (0.524 g, 1.16 mmol, 66%). Anal. Calcd for C15H16Cl2N4OPd:
C, 40.43; H, 3.62; N,12.57. Found: C, 40.08; H, 3.89; N,12.31. 1H NMR
(400 MHz, DMSO-d6):
(d, 1H, eCH2e, 2.9 Hz), 6.66 (d, 1H, eCH2e, 2.9 Hz), 6.91 (d, 2H, H3
d
¼ 3.20 (s, 3H, OMe), 3.77 (s, 3H, Me), 6.50
00
,
00
00
(s, 2H, eCH2e), 7.65 (t, 1H, H4 , 7.2 Hz), 7.72 (dd, 2H, H3 , 7.2 and
8.9 Hz), 6.96 (d, 1H, H4 or H5, 1.7 Hz), 7.41 (d, 1H, H4 or H5, 1.7 Hz),
00
8.0 Hz), 7.76 (d, 2H, H2 , 8.0 Hz), 7.82 (dd, 1H, H4 or H5), 7.98 (dd, 1H,
00
0
0
7.65 (d, 2H, H2 , 8.9 Hz), 7.88 (d, 1H, H4 or H5 , 1.8 Hz), 7.99 (d, 1H,
0
0
0
0
H4 or H5), 8.17 (dd, 1H, H4 or H5 ), 8.40 (dd, 1H, H4 or H5 ), 9.34 (s,
0
0
H4 or H5 , 1.8 Hz).
0
1H, H2), 9.97 (s, 1H, H2 ).
Preparation of dichloro(1-methyl-10-(300,500-diphenylphenyl)-3,30-
methylenediimidazolin-2,20-diylidene)palladium(II)·H2O (4c·H2O)
Preparation of 1-methyl-10-(400-methoxyphenyl)-3,30-
methylenediimidazolium hexafluorophosphate (3b)
A mixture of 3c (1.07 g, 1.57 mmol), PdCl2(NCCH3)2 (416 mg,
1.60 mmol), and NEt3 (0.437 g, 4.32 mmol) in DMSO (13 mL) was
stirred at 40 ꢀC for 2 h, 60 ꢀC overnight, and 80 ꢀC for 4 h. The re-
action was filtered and to the filtrate was added acetone and Et2O.
The resulting precipitates were filtered and washed with acetone.
To a suspension of the crude product in EtOH, we added tetrae-
thylammonium chloride (0.884 g, 5.33 mmol), and this was stirred
at rt overnight. The resulting precipitates were filtered and dried
under vacuum (0.401 g, 0.706 mmol, 45%). Anal. Calcd for
A mixture of 1 (2.62 g, 12.4 mmol) and N-(4-methoxyphenyl)
imidazole (1.90 g, 10.9 mmol) in CH3CN (10 mL) was stirred at 90 ꢀC
overnight in a sealed tube. The resulting precipitates were filtered
and dried under vacuum to yield dihalide salt 2b (3.70 g) as a white
powder. To an aqueous solution of 2b (2.65 g), we added an
aqueous solution of NH4PF6 (2.57 g, 15.8 mmol). The resulting
precipitates were filtered, washed with water, and dried under
vacuum to yield a white powder (3.77 g, 6.73 mmol). Anal. Calcd for
C
15H18F12N4OP2: C, 32.16; H, 3.24; N,10.00. Found: C, 32.48; H, 3.63;
C
26H22Cl2N4Pd$H2O: C, 53.31; H, 4.13; N, 9.56. Found: C, 53.23; H,
3.90; N, 9.45. 1H NMR (400 MHz, addition of LiCl, DMSO-d6):
¼ 4.02 (s, 3H, Me), 6.37 (m, 1H, eCH2e), 6.79 (m, 1H, eCH2e), 7.45
N, 10.27. 1H NMR (400 MHz, DMSO-d6): 3.85 (s, 3H, OMe or Me),
00
3.92 (s, 3H, OMe or Me), 6.67 (s, 2H, eCH2e), 7.24 (d, 2H, H3
,
d
00
0
0
9.1 Hz), 7.68 (d, 2H, H2 , 9.1 Hz), 7.82 (s, 1H, H4, H5, H4 , or H5 ), 7.97
000
000
(m, 3H, H4 or H5, and H4 ), 7.54 (dd, 4H, H3 ), 7.78 (s, 1H, H4 or H5),
0
0
0
0
(s, 1H, H4, H5, H4 , or H5 ), 8.14 (s, 1H, H4, H5, H4 , or H5 ), 8.32 (s, 1H,
00
000
0
0
0
0
7.98 (m, 6H, H4 and H2 , H4 or H5 ), 8.08 (s, 1H, H4 or H5 ), 8.19 (s,
0
0
0
H4, H5, H4 , or H5 ), 9.33 (s, 1H, H2), 9.88 (s, 1H, H2 ).
00
2H, H2 ).
Preparation of 1-methyl-10-(300,500-diphenylphenyl)-3,30-
General procedure for the Heck reaction
methylenediimidazolium hexafluorophosphate (3c)
All reactions were carried out with iodobenzene (2.0 mmol),
styrene (2.8 mmol), NEt3 (2.2 mmol), and the Pd complex
(4.0 mmol) in 5 mL of dry DMA under Ar. Di-p-tolyl ether was used
as an internal standard. The yields of trans-stilbene and 1,1-
diphenylethylene were determined by GC.
A mixture of 1 (0.930 g, 4.40 mmol) and N-(3,5-diphenylphenyl)
imidazole (1.04 g, 3.51 mmol) in CH3CN (7 mL) was stirred at 90 ꢀC
for 4 d in a sealed tube. The resulting precipitates were filtered and
dried under vacuum to afford dihalide salt 2c (1.59 g) as a white
powder. An aqueous solution of NH4PF6 (0.287 g, 1.76 mmol) was
added to an aqueous of 2c (0.359 g). The resulting precipitates were
filtered, washed with water, and dried under vacuum to give a
white powder (0.439 g, 0.643 mmol). Anal. Calcd for C26H24F12N4P2:
C, 45.76; H, 3.54; N, 8.21. Found: C, 45.51; H, 3.43; N, 8.07. 1H NMR
Crystal structure determination
Crystals of 4a and 4c, suitable for X-ray diffraction studies, were
obtained from a DMSOeacetoneeEt2O solution. Crystallographic
and diffraction data were obtained using a Rigaku/MSC Mercury
(400 MHz, DMSO-d6):
d
¼ 3.93 (s, 3H, Me), 6.75 (s, 2H, eCH2e), 7.50
radiation at ꢁ100 ꢀC.
000
000
(t, 2H, H4 , 7.3 Hz), 7.58 (dd, 4H, H3 , 7.3 and 7.6 Hz), 7.84 (dd,1H, H4
CCD with graphite monochromated Mo K
a
000
or H5), 7.92 (d, 4H, H2 , 7.6 Hz), 8.02 (dd, 1H, H4 or H5), 8.07 (d, 2H,
The structures were solved using direct methods and expanded
using Fourier techniques. Atomic scattering factors and anomalous
dispersion terms were taken from International Tables for X-ray
00
00
0
0
H2 ,1.5 Hz), 8.18 (t,1H, H4 ,1.5 Hz), 8.23 (dd,1H, H4 or H5 ), 8.66 (dd,
0
0
0
1H, H4 or H5 ), 9.41 (s, 1H, H2), 10.26 (s, 1H, H2 ).