Page 113 - Catalysts for Fine Chemical Synthesis Vol 1 - Robert & Poignant

unfunctionalized alkenes a, b-unsaturated esters 99

The completion of the oxidation can be checked by monitoring the disappear-
ance and emergence of the Soret bands of the Ru(II) (l max ˆ 426 nm) and the
Ru(VI) (l max ˆ ca:440 nm) complexes using UV±vis spectroscopy. (Note: a
prolonged reaction time (10 minutes) could result in lower product yields.)
2. The product complex was eluted by CH 2 Cl 2 /acetone (1:1 v/v). After solvent
evaporation, a dark purple residue ( 80 mg) was obtained. Yield: 80 %.
3. The solid can be kept in a fridge (4 8C) for about one month without
deterioration.
1
VI
1
[Ru (L )O 2 ] (1a): H NMR (300 MHz, CDCl 3 ): d 8.65 (d, J 4.7 Hz, 4H),
8.55 (d, J 4.7 Hz, 4H), 7.77 (t, J 6.5 Hz, 4H), 7.22±7.38 (m, meta-H over-
lapped with a solvent peak, 8H), 4.91 (d, J 10.4 Hz, 4H), 4.62 (d, J 9.0 Hz,
4H), 4.43 (t, J 9.0 Hz, 4H), 4.22 (d, J 10.1 Hz, 4H), 3.76 (d, J 9.0 Hz, 4H),
2.60 (t, J 8.5 Hz, 4H), 0.77 (s, 12H), ÿ0.78 (s, 12H).
IR (KBr): 818 (n RuˆO ), 1018 cm ÿ1 (oxidation state marker band).
3
ÿ1
ÿ1
UV±vis (CH 2 Cl 2 ) l max =nm (log e=dm mol cm ): 442 (5.12), 536 (4.07).
FAB±MS m/z: 1379 (M , 18 %), 1363 (M ±O, 30 %), 1347 (M ±2O,
‡
‡
‡
100 %).
VI
1
2
[Ru (L )O 2 ] (1b): H NMR (300 MHz, CDCl 3 ): d 8.64 (d, J 4.7 Hz, 4H),
8.53 (d, J 4.7 Hz, 4H), 7.74 (m, 4H), 7.37±7.30 (m, meta-H overlapped with a
solvent peak, 8H), 4.98 (d, J 10.4 Hz, 4H), 4.60 (d, J 8.8 Hz, 4H), 4.44 (t, J
8.9 Hz, 4H), 4.23 (d, J 10.4 Hz, 4H), 3.74 (d, J 8.8 Hz, 4H), 2.63 (t, J 8.7 Hz,
4H), 1.02 (m, 8H), 0.53 (t, J 7.2 Hz, 12H), ÿ0.25 (m, 8H), ÿ1.37 (t, J 7.3 Hz,
12H).
IR (KBr): 821 (n RuˆO ), 1019 cm ÿ1 (oxidation state marker band).
ÿ1
3
ÿ1
UV±vis (CH 2 Cl 2 ): l max =nm (log e=dm mol cm ) 443 (5.15), 534 (4.02).
FAB±MS: m/z 1491 (M , 9 %), 1475 (M ±O, 20 %), 1459 (M ±2O, 100 %).
‡
‡
‡
1
3
VI
[Ru (L )O 2 ] (1c): H NMR (300 MHz, CDCl 3 ): d 8.67 (d, J 4.6 Hz, 4H),
8.56 (d, J 4.6 Hz, 4H), 7.76 (m, 4H), 7.20±7.37 (m, meta-H overlapped with a
solvent peak, 8H), 4.88 (d, J 9.3 Hz, 4H), 4.60 (d, J 9.4 Hz, 4H), 4.64 (t, J
9.0 Hz, 4H), 4.24 (d, J 10.1 Hz, 4H), 3.77 (d, J 8.6 Hz, 4H), 2.57 (t, J 8.6 Hz,
4H), 0.83 (m, 12H), 0.60 (m, 12H), ÿ0.32 (m, 4H), ÿ1.16 (m, 4H).
IR (KBr): 819 (n RuˆO ), 1019 cm ÿ1 (oxidation state marker band).
ÿ1
ÿ1
3
UV±vis (CH 2 Cl 2 ) l max =nm (log e=dm mol cm ): 441 (5.03), 535 (4.02).
FAB±MS m/z: 1483 (M , 8 %), 1467 (M ±O, 22 %), 1451 (M ±2O, 100 %).
‡
‡
‡
6.3.2 ENANTIOSELECTIVE EPOXIDATION OF (E)-b-
METHYLSTYRENE
R*
R* O
Ph [Ru VI (L 1 )O 2 ] Ph O O O O
O
N N
* * N Ru N
Me Me O O O
R* O
O
R*