K.-M. Wu et al. / Tetrahedron 61 (2005) 9679–9687
9685
1
1
1
28.7, 130.1, 135.4, 137.6, 148.4(CH of Ph or Py), 127.1,
31.9, 135.2, 152.3, 159.0 (three Cipso–C H , one metallated
4.2.9. [C H –C{]NC H Oxazoline}–NH–(h -C H )]
6 5 6 4 6 5
PdCl (9). To a flask containing 6 (0.53 g, 0.5 mmol) and
LiCl (0.17 g, 4.0 mmol), 15 ml of CHCl was added at room
6
5
C–Ph, and one CNN), 178.2 (s, O–C(]O)CH ). Anal.
3
3
Calcd for C H N O Pd: C, 55.82; H, 4.24; N, 9.30.
1 19 3 2
Found: C, 55.79; H, 4.19; N, 9.52.
temperature. After 18 h of stirring, the resulting mixture was
filtered and the volatiles were removed under reduced
pressure. The crude product was recrystallized from CHCl3/
2
1
.2.6. [C H –C{]NC H Oxazoline}–NH–(h -C H )]
4
Pd(OAc) (6). To a flask containing 3 (0.65 g, 1.75 mmol)
hexane to afford yellow solid after several days. Yield,
6
5
6
4
6
5
1
0.38 g, 75%. H NMR (600 MHz): d 1.81 (s, C(CH
)
, 3H),
, 1H, JZ7.8 Hz), 4.38
, 1H, JZ8.4 Hz), 6.27 (d, C , 1H, JZ7.8 Hz),
6.91 (t, C , 2H, JZ7.8 Hz), 6.98 (t, C , 1H, JZ
7.8 Hz), 7.03 (t, C , 1H, JZ7.8 Hz), 7.10 (d, C , 1H,
JZ7.8 Hz), 7.29 (overlap, C , 2H), 7.33 (t, C , 2H,
JZ7.8 Hz), 7.41 (t, C , 1H, JZ7.8 Hz), 7.74 (m, C
3
2
and Pd(OAc) (0.39 g, 1.75 mmol), 15 ml of CH Cl was
2
1.87 (s, C(CH
(d, CH
) , 3H), 4.18 (d, CH
3 2 2
2
2
added at room temperature. After 18 h of stirring, the
resulting mixture was layered 15 ml hexane and put into
the fridge. The crystalline solid was isolated after several
2
H
6 5
H
5
H
6 5
6
H
6
H
6 5
5
1
days. Yield, 0.61 g, 65%. H NMR (600 MHz): d 1.59
(s, C(CH ) , 3H), 1.89 (s, C(CH ) , 3H), 1.92 (s, O–C(]O)
CH , 3H), 4.34 (m, CH , 2H), 6.13 (m, C H , 1H), 6.21 (br,
6
H
5
H
6 5
H
H
,
3
2
3 2
6
5
6
5
1
3
1
2H), 8.18 (s, NH, 1H). C{ H} NMR (150 MHz): d 27.5 (s,
C(CH ), 28.6 (s, C(CH ), 70.7 (s, C(CH ), 81.2 (s,
CH ), 115.0, 124.2, 124.3, 125.2, 127.6, 129.1, 129.2, 130.2,
131.7, 132.2, 139.9(C ), 120.9, 126.0, 133.5, 146.4,
156.5, 161.1 (one tert-C-oxazoline, one tert-C-Ph, three
, one metallated C–Ph, and one CNN; one tert-C
is missed). Anal. Calcd for C24 22ClN OPd: C, 56.49; H,
3
2
6 5
C H , 1H), 6.76–6.87 (overlap, C H , 4H), 7.16 (t, C H ,
6
3
)
2
3
)
2
)
3 2
5
6
5
6 5
2
H, JZ7.8 Hz), 7.24 (m, C H , 1H), 7.29 (d, C H , 2H,
2
6
5
6 5
JZ7.2 Hz), 7.64 (m, C H , 1H), 8.58 (br, C H , 1H),
H
6 5
6
5
6 5
1
3
1
0.10 (s, NH, 1H). C{ H} NMR (150 MHz): d 25.2 (s,
1
O–C(]O)CH ), 27.8 (s, C(CH ) ), 28.9 (s, C(CH ) ), 69.3
C
ipso–C H
6 5
3
3 2
3 2
(
s, C(CH ) ), 80.7 (s, CH ), 122.9, 123.8, 124.0, 127.5,
3
H
3
2
2
1
28.6, 128.9, 130.2, 131.4, 131.6, 133.6, 135.0(C H ),
6
4.35; N, 8.23. Found: C, 55.32; H, 4.07; N, 7.95.
5
1
17.8, 119.7, 126.2, 132.5, 147.9, 156.2, 161.2 (one tert-C-
oxazoline, one tert-C-Ph, three Cipso–C H , one metallated
C-Ph, and one CNN), 178.0 (s, O–C(]O)CH ). Anal. Calcd
3
4.3. General procedure for the Suzuki-type coupling
reaction
6
5
for dC H N O Pd: C, 58.49; H, 4.72; N, 7.87. Found: C,
2
6 25 3 3
5
8.28; H, 4.81; N, 7.58.
Prescribed amounts of catalyst, aryl halide (1.0 equiv),
phenylboronic acid (1.5 equiv), base (3.0 equiv), and a
magnetic stir bar were placed in a Schlenk tube under
nitrogen. Toluene (3 ml) was added by syringe, and the
reaction mixture was heated in an oil bath at 80 8C for the
prescribed time. After removal of the volatiles, the residue
was diluted with ethyl acetate, filtered through a pad of
silica gel. A sample in chloroform-d was taken for
determination of conversion. The crude material was further
purified by flash chromatography on silica gel.
1
.2.7. [C H –C{]N(CH ) NMe }–NH–(h -C H )]PdCl
4
6
5
2 2
2
6
5
(
(
7). To a flask containing 4 (0.22 g, 0.5 mmol) and LiCl
0.085 g, 2.0 mmol), 15 ml of CHCl was added at room
3
temperature. After 18 h of stirring, the resulting mixture was
filtered and layered 15 ml hexane. The white solid was
isolated after several days. Yield, 0.16 g, 82%. H NMR
1
(
600 MHz): d 2.50 (t, CH , 2H, JZ6.0 Hz), 2.72 (s,
2
N(CH ) , 6H), 3.47 (t, CH , 2H, JZ6.0 Hz), 6.61 (m,
3
2
2
C H , 1H), 6.88 (m, C H , 1H), 7.00 (m, C H , 1H), 7.02 (s,
NH, 1H), 7.40 (m, C H , 2H), 7.55–7.59 (overlap, C H ,
6
5
6
5
6 5
4.4. General procedure for the Heck reaction
6
5
1
6 5
3
1
3
H), 8.44 (m, C H , 1H). C{ H} NMR (150 MHz): d 48.2
6 5
(
1
1
s, N(CH ) ), 53.4 (s, CH ), 62.5 (s, CH ), 115.1, 122.6,
3
Prescribed amount of catalyst, base (1.5 equiv) and aryl
halide (1 equiv) were placed in a Schlenk tube under
nitrogen. Solvent (2 ml) and styrene (1.3 equiv) were added
by syringe, and the reaction mixture was heated to the
prescribed temperature for the prescribed time. After
removal of the volatiles, the residue was diluted with
ethyl acetate, filtered through a pad of silica gel. A sample in
chloroform-d was taken for determination of conversion.
The crude material was further purified by flash chroma-
tography on silica gel.
2
2
2
25.0, 127.2, 129.6, 130.9, 141.1(CH–Ph), 123.6, 132.6,
34.1, 151.6 (two Cipso–C H , one metallated C-Ph, and one
6
5
CNN). Anal. Calcd for C H ClN Pd: C, 50.02; H, 4.94; N,
1
1
7
20
3
0.29. Found: C, 50.11; H, 4.84; N, 9.92.
1
.2.8. [C H –C{]NCH Py}–NH–(h -C H )]PdCl (8).
4
6
5
2
6
5
To a flask containing 5 (0.23 g, 0.5 mmol) and LiCl
0.085 g, 2.0 mmol), 15 ml of CHCl was added at room
(
3
temperature. After 18 h of stirring, the resulting mixture was
filtered and layered 15 ml hexane. The white solid was
isolated after several days. Yield, 0.16 g, 71%. H NMR
1
4.5. Crystal structure data
(
600 MHz): d 4.88 (s, CH Py, 2H), 6.68 (m, C H or Py,
2 6 5
1
7
H), 6.95 (m, C H or Py, 1H), 7.06 (m, C H or Py, 1H),
6
Crystals were grown from concentrated hexane solution (1),
toluene/hexane solution (3), concentrated dichloromethane
solution (5), or CH Cl /hexane solution (6 and 7), and
5
6 5
.17 (d, C H or Py, 1H, JZ7.8 Hz), 7.18 (s, NH, 1H), 7.34
6
5
(
t, C H or Py, 1H, JZ6.6 Hz), 7.46 (m, C H or Py, 2H),
6 5 6 5
2
2
7
8
1
1
1
1
.60–7.65 (m, C H or Py, 3H), 7.74 (m, C H or Py, 1H),
.52 (d, C H or Py, 1H, JZ7.8 Hz), 9.37 (d, C H or Py,
isolated by filtration. Suitable crystals of 1, 3, 5, 6 or 7 were
sealed in thin-walled glass capillaries under a nitrogen
atmosphere and mounted on a Bruker AXS SMART 1000
diffractometer. The absorption correction was based on the
symmetry equivalent reflections using the SADABS
program. The space group determination was based on a
check of the Laue symmetry and systematic absences and
was confirmed using the structure solution. The structure
6
5
6 5
6
5
6 5
1
3
1
H, JZ4.8 Hz). C{ H} NMR (150 MHz): d 62.8 (s, CH ),
2
15.3, 119.6, 122.8, 123.1, 125.1, 127.1, 129.8, 131.1,
37.8, 141.2, 149.6(CH of Ph or Py), 125.6, 132.4, 133.6,
52.4, 158.7 (three Cipso–C H , one metallated C–Ph, and
6
5
one CNN), Anal. Calcd for C H ClN Pd: C, 53.29; H,
16
1
9
3
3
.77; N, 9.81. Found: C, 52.91; H, 4.33; N, 9.43.