Transition Metal Chemistry
was removed under reduced pressure, and the residue was
placed on an Al2O3 column. Elution with CH2Cl2/petro-
leum ether developed a purple black band, which aforded
0.175 g (41.3%) of 7 as black crystals. Mp: 134.2 °C; Anal.
Calcd for C16H10N2O4Mo: C, 49.25; H, 2.58; N, 7.18, Found
(%): C, 49.55; H, 2.80; N, 7.43. 1H NMR (ppm in DMSO,
500 MHz): δ 7.43–7.47 (m, 1H, C6H1), 7.54–7.60 (m, 4H,
C6H4), 7.71–7.74 (m, 1H, N=C(H)), 8.21–8.26 (m, 2H,
Py-H2), 8.97 (s, 1H, Py-H), 9.05 (d, 1H, J = 5.5 Hz, Py-H);
13C NMR (DMSO, 125 MHz): δ 122.5, 128.305, 128.9,
129.7, 130.4, 139.1, 152.2, 153.2, 154.4, 166.3, 203.9.
IR(υCO, KBr, cm−1): 2018(s), 1885(s), 1815(s).
Mo(CO)6 gave product 11 in 40.1% yield as black solid.
Mp: 137.5 °C; Anal. Calcd for C16H9ClN2O4Mo: C, 45.25;
H, 2.14; N, 6.60, Found (%): C, 45.52; H, 2.35; N, 6.38.
1H NMR (ppm in DMSO, 500 MHz): δ 7.61–7.66 (m, 4H,
C6H4), 7.73–7.76 (m, 1H, N=C(H)), 8.24 (q, 2H, J = 6.0 Hz,
Py-H), 8.98 (s, 1H, Py-H), 9.06 (d, 1H, J = 5.0 Hz, Py-H);
13C NMR (DMSO, 125 MHz): δ 124.3, 128.4, 129.7, 130.6,
133.1, 139.1, 150.9, 153.3, 154.3, 166.9, 203.8. IR(υCO
,
KBr, cm−1): 2013(s), 1886(s), 1816(s).
Synthesis of 12 By using a procedure similar to that
described above, reaction of ligand precursor 6 with
Mo(CO)6 gave product 12 in 42.3% yield as black solid.
Mp: 138.3 °C; Anal. Calc. for C16H9BrN2O4Mo: C, 40.97;
H, 1.93; N, 5.97, Found (%): C, 41.22; H, 1.68; N, 6.25. 1H
NMR (ppm in CDCl3, 500 MHz): δ 7.38 (d, 2H, J = 8.5 Hz,
C6H2), 7.46–7.49 (m, 1H, N=C(H)), 7.61 (d, 2H, J = 8.5 Hz,
C6H2), 7.87 (d, 1H, J = 7.5 Hz, Py-H), 7.93–7.96 (m, 1H,
Py-H), 8.57 (s, 1H, Py-H), 9.20 (d, 1H, J = 5.5 Hz, Py-H);
13C NMR (DMSO, 125 MHz): δ 124.3, 128.5, 129.7, 130.6,
Synthesis of 8 By using a procedure similar to that
described above, reaction of ligand precursor 2 with
Mo(CO)6 gave product 8 in 41.5% yield as black crystals.
Mp: 135.3 °C; Anal. Calcd for C17H12N2O4Mo: C, 50.51;
H, 2.99; N, 6.93, Found (%): C, 50.28; H, 3.23; N, 7.15.
1H NMR (ppm in DMSO, 500 MHz): δ 2.37 (s, 3H, CH3),
7.34 (d, 2H, J = 8.0 Hz, C6H2), 7.48 (d, 2H, J = 8.5 Hz,
C6H2), 7.68–7.71 (m, 1H, N=C(H)), 8.20 (d, 2H, J = 6.0 Hz,
Py-H2), 8.92 (s, 1H, Py-H), 9.02 (d, 1H, J = 5.5 Hz, Py-H);
13C NMR (DMSO, 125 MHz): δ 121.1, 122.4, 128.2, 130.1,
130.3, 138.9, 139.1, 149.8, 153.2, 154.5, 165.4, 203.9.
IR(υCO, KBr, cm−1): 2013(s), 1889(s), 1811(s).
133.1, 139.2, 150.9, 153.3, 154.3, 166.9, 203.8. IR(υCO
,
KBr, cm−1): 2013(s), 1887(s), 1813(s).
Crystal structure determination
Synthesis of 9 By using a procedure similar to that
described above, reaction of ligand precursor 3 with
Mo(CO)6 gave product 9 in 42.5% yield as black solid. Mp:
136.2 °C; Anal. Calcd for C17H12N2O5Mo: C, 48.59; H,
Crystals of complexes 7, 8 and 10 suitable for X-ray dif-
fraction were investigated with a Bruker AXS SMART
1000 CCD difractometer, using graphite monochromated
Mo Kα radiation (φ/ω scan, λ = 0.71073 Å). Semiempiri-
cal absorption corrections were applied for all complexes.
The structures were solved by direct methods and refned by
the SHELXL-97 program system [31]. Crystallographic data
given in Table 3. Selected bond lengths and angles are given
1
2.88; N, 6.67, Found (%): C, 49.84; H, 2.53; N, 6.89. H
NMR (ppm in CDCl3, 500 MHz): δ 3.87 (s, 3H, OCH3),
6.99 (d, 2H, J = 9.0 Hz, C6H2), 7.41–7.44 (m, 1H, N=C(H)),
7.52 (d, 2H, J = 9.0 Hz, C6H2), 7.82 (d, 1H, J = 8.0 Hz,
Py-H), 7.90–7.93 (m, 1H, Py-H), 8.49 (s, 1H, Py-H), 9.18
(d, 1H, J = 5.0 Hz, Py-H); 13C NMR (DMSO, 125 MHz): δ
56.1, 114.8, 123.9, 127.9, 130.1, 139.1, 145.4, 153.1, 154.6,
159.9, 164.4, 204.0. IR(υCO, KBr, cm−1): 2012(s), 1880(s),
1820(s).
General procedure for catalytic tests
Synthesis of 10 By using a procedure similar to that
described above, reaction of ligand precursor 4 with
Mo(CO)6 gave product 10 in 47.2% yield as black crys-
tals. Mp: 140.3 °C; Anal. Calcd for C17H9F3N2O4Mo: C,
44.56; H, 1.98; N, 6.11, Found (%): C, 44.39; H, 2.20; N,
The catalytic reactions were carried out under an argon
atmosphere with magnetic stirring. The required Mo com-
plex (0.4 mmol) and o-chloranil (0.57 g, 2.4 mmol) was
mixed with 1,2-dichloroethane (4.5 mL) in a 25-mL round-
bottom fask at room temperature. Aromatic compounds
(2 mmol) and acylation reagents (2 mmol) were added
by syringe. The reaction mixture was heated at 80 °C for
24 h. After cooling to room temperature, the solid catalyst
was separated from the reaction mixture by fltration. The
solvent was removed by rotary evaporation, and the resi-
due was purifed by Al2O3 column chromatography, elut-
ing with petroleum ether and dichloromethane to give the
1
6.34. H NMR (ppm in CDCl3, 500 MHz): δ 7.56 (d, 2H,
J = 8.5 Hz, C6H2), 7.76 (d, 2H, J = 8.5 Hz, C6H2), 7.82
(d, 1H, J = 8.0 Hz, Py-H), 7.91 (d, 1H, J = 8.0 Hz, Py-H),
7.95–7.99 (m, 1H, N=C(H)), 8.57 (s, 1H, Py-H), 9.21 (d,
1H, J = 5.0 Hz, Py-H); 13C NMR (DMSO, 125 MHz): δ
123.4, 124.3, 127.05, 127.1, 128.7, 129.7, 130.9, 139.2,
153.3, 154.2, 168.1, 203.7. IR(υCO, KBr, cm−1): 2010(s),
1885 (s), 1815(s).
Synthesis of 11 By using a procedure similar to that
described above, reaction of ligand precursor 5 with
1 3