CHarom), 7.24 (d, J = 9.1 Hz, 1H, CHarom), 7
CHarom), 6.83–6.74 (m, 1H, CHarom), 6.52 (t, J = 6.8 Hz, 1H, 60 methane were used as ligand precursors. Yield: 37% (175 mg).
A
.18
C
–7
C
.03
E
(
P
m
T
,
E
3H
D
,
MA(0.
N
8 m
U
m
S
ol
C
) o
R
f
I
5
P
a
T
nd 0.68 mL (602 mg, 3.2 mmol) dipivaloyl-
CHarom), 5.88 (s, 1H, CH), 1.31 (s, 9H, CH3), 1.29 (s, 9H, CH3)
ppm. 13C NMR (125 MHz, CDCl3): δ 194.6 (CO), 194.5 (CO),
146.9 (Ci), 142.0 (NCN), 131.9 (CHarom), 129.5 (Ci), 127.4 (Ci),
126.3 (CHarom), 125.2 (CHarom), 123.4 (CHarom), 121.6 (CHarom),
1H NMR (300 MHz, CDCl3): δ 9.19 (dd, J = 1.0 Hz, J = 7.3 Hz,
1H, CHarom), 8.23–7.99 (m, 1H, CHarom), 7.53 (s, 1H, CHarom),
7.39 (dd, J = 1.8 Hz, J = 8.0 Hz, 1H, CHarom), 7.23 (m, 1H,
CHarom), 7.14 (d, J = 8.1 Hz, 1H, CHarom), 6.83 (dd, J = 6.4 Hz, J
5
117.7 (CHarom), 113.0 (CHarom), 111.5 (CHarom), 103.8 (CHarom), 65 = 10.2 Hz, 1H, CHarom), 6.62–6.52 (m, 1H, CHarom), 5.92 (s, 1H,
92.9 (CH), 41.9 (Ci), 41.4 (Ci), 28.8 (CH3), 28.6 (CH3) ppm. 195Pt
NMR (64 MHz, CDCl3): δ -3434 ppm. M.p.: 201–203 °C. Anal.
10 calcd for C24H28N2O2Pt: C 50.43, H 4.94, N 4.90; found: C 50.77,
H 5.09, N 4.80%.
CH), 1.33 (s, 9H, CH3), 1.31 (s, 9H, CH3) ppm. 13C NMR
(75 MHz, CDCl3): δ 195.0 (CO), 194.9 (CO), 150.6 (Ci), 142.6
(NCN), 134.9 (CHarom), 130.1 (Ci), 129.0 (Ci), 128.3 (CHarom),
126.1 (CHarom), 122.5 (CHarom), 120.0 (Ci), 117.8 (CHarom), 113.7
70 (CHarom), 111.6 (CHarom), 108.2 (Ci), 104.2 (CHarom), 93.2 (CH),
42.0 (Ci), 41.4 (Ci), 28.8 (CH3), 28.6 (CH3) ppm. 195Pt NMR
(64 MHz, CDCl3): δ -3408 ppm. M.p.: dec. > 290 °C. Anal. calcd
for C25H27N3O2Pt: C 50.33, H 4.56, N 7.04; found: C 50.59, H
4.53, N 7.04%.
(SP-4-4)-dipivaloylmethanato-[2-(4-Methoxyphenyl)-2H-
imidazo[1,5-a]pyridin-3-ylidene-κC3,κC2‘]platinum(II) (11): The
15 synthesis followed the general procedure while the reaction time
of the second step was increased from 21 h to 45 h. 223 mg
(0.8 mmol) of 3 and 0.68 mL (602 mg, 3.2 mmol) dipivaloyl-
methane were used as ligand precursors. Additionally silver(I)
acetate (134 mg, 0.8 mmol) was added to the last reaction step.
20 Yield: 40% (192 mg). 1H NMR (500 MHz, CDCl3): δ 9.20 (d, J =
7.3 Hz, 1H, CHarom), 7.51 (d, J = 2.8 Hz, 1H, CHarom), 7.48 (s,
75
(SP-4-4)-dipivaloylmethanato-[2-(4-Methoxyphenyl)-1-phenyl-
2H-imidazo[1,5-a]pyridin-3-ylidene-κC3,κC2‘]platinum(II) (14):
The synthesis followed the general procedure while the reaction
time of the second step was increased from 21 h to 45 h. 219 mg
1H, CHarom), 7.23 (d, J = 9.1 Hz, 1H, CHarom), 7.06 (d, J = 8.5 Hz, 80 (0.8 mmol) of
6
and 0.68 mL (602 mg, 3.2 mmol)
1H, CHarom), 6.81–6.73 (m, 1H, CHarom), 6.64 (dd, J = 2.8 Hz, J =
8.5 Hz, 1H, CHarom), 6.51 (t, J = 7.3 Hz, 1H, CHarom), 5.87 (s, 1H,
25 CH), 3.87 (s, 3H, OCH3), 1.32 (s, 9H, CH3), 1.29 (s, 9H, CH3)
ppm. 13C NMR (125 MHz, CDCl3): δ 194.6 (CO), 194.4 (CO),
dipivaloylmethane were used as ligand precursors. Yield: 15%
(83 mg). H NMR (500 MHz, CDCl3): δ 9.30 (d, J = 7.3 Hz, 1H,
CHarom), 7.63–7.45 (m, 6H, CHarom), 7.03 (d, J = 9.1 Hz, 1H,
CHarom), 6.68 (dd, J = 6.6 Hz, J = 8.8 Hz, 1H, CHarom), 6.56 (d, J
1
156.9 (Ci), 140.4 (NCN), 129.4 (Ci), 129.3 (Ci), 126.1 (CHarom), 85 = 8.5 Hz, 1H, CHarom), 6.52 (t, J = 6.8 Hz, 1H, CHarom), 6.33 (dd,
121.4 (CHarom), 117.6 (CHarom), 116.2 (CHarom), 112.9 (CHarom),
112.3 (CHarom), 109.0 (CHarom), 103.7 (CHarom), 93.0 (CH), 55.4
30 (OCH3), 42.0 (Ci), 41.4 (Ci), 28.8 (CH3), 28.6 (CH3) ppm. 195Pt
NMR (64 MHz, CDCl3): δ -3416 ppm. M.p.: 189–190 °C. Anal.
J = 2.8 Hz, J = 8.8 Hz, 1H, CHarom), 5.89 (s, 1H, CH), 3.82 (s,
3H, OCH3), 1.33 (s, 9H, CH3), 1.31 (s, 9H, CH3) ppm. 13C NMR
(125 MHz, CDCl3): δ 194.7 (CO), 194.6 (CO), 156.4 (Ci), 141.1
(Ci), 140.9 (NCN), 130.9 (CHarom), 130.2 (Ci), 129.3 (CHarom),
calcd for C25H30N2O3Pt: C 49.91, H 5.03, N 4.66; found: C 50.19, 90 129.0 (CHarom), 128.0 (Ci), 127.6 (Ci), 125.8 (CHarom), 121.1
H 5.15, N 4.74%.
(CHarom), 120.1 (Ci), 117.2 (CHarom), 115.9 (CHarom), 115.1
(CHarom), 113.3 (CHarom), 108.5 (CHarom), 93.0 (CH), 55.3
(OCH3), 42.0 (Ci), 41.5 (Ci), 28.8 (CH3), 28.6 (CH3) ppm. 195Pt
NMR (64 MHz, CDCl3): δ -3444 ppm. M.p.: 231–233 °C. Anal.
35 (SP-4-4)-[2-(4-Bromophenyl)-2H-imidazo[1,5-a]pyridin-3-
ylidene-κC3,κC2‘]platinum(II)dipivaloylmethanato (12): The
synthesis followed the general procedure while the reaction time 95 calcd for C31H34N2O3Pt: C 54.94, H 5.06, N 4.13; found: C 54.97,
of the second step was increased from 21 h to 45 h. 262 mg
(0.8 mmol) of 4 and 0.68 mL (602 mg, 3.2 mmol) dipivaloyl-
40 methane were used as ligand precursors. Yield: 43% (221 mg).
1H NMR (500 MHz, CDCl3): δ 9.19 (d, J = 7.3 Hz, 1H, CHarom),
H 5.22, N 4.21%.
p-Bis([(SP-4-4)-dipivaloylmethanato-(2H-imidazo[1,5-a]pyridin-
3-ylidene-κC3)platinum(II)]-κN2,κPt1,κN2‘,κPt1‘)phenylene
7.98 (d, J = 1.9 Hz, 1H, CHarom), 7.49 (s, 1H, CHarom), 7.22 (td, J 100 (15): Silver(I) oxide (0.28 g, 1.2 mmol) and 7 (0.32 g, 0.8 mmol)
= 2.7 Hz, J = 8.5 Hz, 2H, CHarom), 6.99 (d, J = 8.2 Hz, 1H,
CHarom), 6.79 (dd, J = 6.1 Hz, J = 9.3 Hz, 1H, CHarom), 6.53 (t, J =
45 7.4 Hz, 1H, CHarom), 5.88 (s, 1H, CH), 1.31 (s, 9H, CH3), 1.29 (s,
9H, CH3) ppm. 13C NMR (125 MHz, CDCl3): δ 194.8 (CO),
were stirred in 20 mL of 1,4-dioxane under argon at room
temperature for 72 h. Pt(COD)Cl2 (0.75 g, 2.0 mmol) and 10 mL
of 2-butanone were added and the reaction mixture was refluxed
for 48 h at 115 °C. Afterwards, all volatiles were removed in
194.6 (CO), 145.9 (Ci), 141.5 (NCN), 134.4 (CHarom), 130.4 (Ci), 105 vacuo and potassium tert-butanolate (0.72 g, 6.4 mmol),
129.7 (Ci), 126.1 (CHarom), 126.0 (CHarom), 121.9 (CHarom), 118.8
(Ci), 117.7 (CHarom), 113.3 (CHarom), 112.9 (CHarom), 104.0
50 (CHarom), 93.1 (CH), 41.9 (Ci), 41.4 (Ci), 28.8 (CH3), 28.6 (CH3)
ppm. 195Pt NMR (64 MHz, CDCl3): δ -3406 ppm. M.p.: 240–
dipivaloylmethane (1.20 g, 1.34 mL, 6.4 mmol) and 20 mL of
DMF were added to the dried reaction mixture. The mixture was
then stirred for 60 h at room temperature and for 7 h at 100 °C.
Finally, all volatiles were removed in vacuo again and the
241 °C. Anal. calcd for C24H27BrN2O2Pt: C 44.32, H 4.18, N 110 remaining solid was extracted with methylene chloride. The final
4.31; found: C 44.26, H 4.13, N 4.40%.
product was obtained by flash chromatography on silica with
methylene chloride as eluent. After evaporation to dryness the
solid was washed with diethyl ether and isohexane. Yield: 5.2%
55 (SP-4-4)-[2-(4-Cyanophenyl)-2H-imidazo[1,5-a]pyridin-3-
ylidene-κC3,κC2‘]platinum(II)dipivaloylmethanato (13): The
1
(44 mg). H NMR (300 MHz, CDCl3): δ 9.20 (d, J = 8.1 Hz, 2H,
synthesis followed the general procedure while the reaction time 115 CHarom), 7.70 (s, 2H, CHarom), 7.51 (s, 2H, CHarom), 7.27 (m, 2H,
of the second step was increased from 21 h to 45 h. 219 mg CHarom), 6.76 (dd, J = 6.9 Hz, J = 9.9 Hz, 2H, CHarom), 6.51 (t, J =
- 4 -