4
W. Zawartka et al. / Inorganica Chimica Acta xxx (2016) xxx–xxx
O
I
O
CO, [Pd], anisole, K CO
2
3
+
+
O
O
OH
0
1
00 C, 5 hours
B
OH
product a
product b
catalyst (1) - product a 92%, product b 8%
catalyst (2) - product a 94%, product b 6%
Fig. 5. Carbonylative Suzuki–Miyaura coupling reaction.
O
[
Pd], THF, Cu(BF4)2
reaction was followed by TLC until the all amount of alcohol
reacted. The excess of HCl gas was removed from the mixture
by addition of K CO .The reaction mixture was filtered with a
2 3
+
O
+
O
0
OH
60 C, 24 hours
B
OH
product c
product d
Schott glass filter. The product of the reaction (straw yellow liq-
uid) is very moisture-sensitive, so it was used for further reac-
tion without separation.
catalyst (1) - product c 15%, product d 15%
catalyst (2) - product c 15%, product d 15%
ee for product c - 10%
Step 2. In a 50 mL round bottom flask equipped with a magnetic
stirrer imidazole (0.4 g; 6.0 mmol) was dissolved in 10 mL of
Fig. 6. Asymmetric Heck-type reaction.
2 2
CH Cl . The hexane solution of the chloro-ether obtained in
the previous reaction was added drop-wise to the imidazole
solution. The reaction was left for 1 h at room temperature
and monitored by TLC. GC-FID analysis showed full conversion
of the substrates. The prepared chiral imidazole was used for
further reaction without separation and purification.
O
O
[
Pd], acetone, Cu(BF4 )2
R
+
OH
0
5
0 C, 24 hours
B
R
OH
R - H, Me
catalyst (1) - H - 69%, Me - 40%
catalyst (2) - H - 70%, Me - 40%
2 2
Step 3. To the prepared solution of PdCl (MeCN) (0.78 g;
3
.0 mmol) in 10 mL of CH Cl , the solution of the imidazole
2
2
Fig. 7. Asymmetric conjugate addition of substituted 2-cyclohexen-1-one.
obtained in previous reaction was added drop-wise. The reac-
tion was left for 1 h at room temperature. The solvents were
removed on rotary evaporator. The crude compound was dis-
3
.2. GC-FID and GC/MS
solved in warm CH
was recrystallized from CHCl
ray diffraction analysis. Yield: 1.5 g (80%).
2
Cl
2
, and precipitated by addition of DEE. It
Spectra of organic products were obtained using HP 5890 (Hew-
3
. One crystal was used for the X-
lett Packard) instrument with mass detector 5971A. Capillary col-
umn HP 5 was used with non-polar liquid phase containing 95%
of dimethyl- and 5% of diphenylpolysiloxane.
2 4 2
Elemental analysis (1) Anal. Calc. for C28H46Cl N O Pd: C 51.9,
H 7.2, N 8.6. Found: C 50.2, H 6.7, N 8.2%;
3
.3. NMR
Refraction index, n = (À)89.5 (10.0 mg/mL, CHCl
3
, 22 °C)
): d = 8.09 (s, 1H, ANACHANA),7.41 (s, 1H,
ACH@CHA), 6.87 (s, 1H, ACH@CHA), 5.19 (d, 2H, NACH AO, JH-
= 7.27 Hz), 3.51 (m, 1H, OACHA), 1.87; 1.83; 1.62; 1.57; 1.15;
.11; 0.78 (m, 7H, bornyl ring), 0.76 (s, 1H, ACH ), 0.73 (s, 1H,
), 0.70 (s, 1H, ACH ),
): d = 145.4 (ANACHANA), 121.7, 121.6
(ACH@CHA), 85.0 (OACH), 77.8 (NACH AO), 49.1; 47.3; 44.9;
35.4; 27.7; 26.1; 18.9; 18.1; 12.8 (bornyl ring),
1
H NMR (CDCl
3
The measurements were performed using Bruker 500 spec-
2
trometer with an autosampler.
H
1
3
3.4. X-ray structure determination
ACH
3
3
1
3
C
NMR (CDCl
3
A single crystal of (2) suitable for X-ray measurements was
2
mounted on a glass fiber and the diffraction data were collected
on a KM-4 CCD diffractometer with graphite monochromated Mo
2 4 2
Elemental analysis (2) Anal. Calc. for C28H46Cl N O Pd: C 51.9,
Ka
radiation (k = 0.71073 Å). The structure was subsequently
H 7.2, N 8.6. Found: C 50.7, H 6.6, N 8.2%;
solved using direct methods and developed by full least-squares
refinement on F . Structural solution and refinement was carried
Refraction index, n = (+)98.8 (10.0 mg/mL, CHCl
H NMR (CDCl
3
3
, 22 °C)
): d = 8.11 (s, 1H, ANACHANA),7.43 (s, 1H,
ACH@CHA), 6.87 (s, 1H, ACH@CHA), 5.16 (d, 2H, NACH AO, JH-
= 7.27 Hz), 2.90 (s, 1H, OACHA), 1.58; 1.37; 1.33; 1.03; 1.01;
2
1
out using SHELX suite of programs [30]. C, N, O, Cl and Pd atoms were
refined anisotropically. All H atoms were positioned geometrically
and refined isotropically using a riding model with a common fixed
isotropic thermal parameter. The molecular structure plots were
prepared using ORTEP-3 program [31].
2
H
3
0.95; 0.80 (m, 7H, bornyl ring), 0.88 (s, 1H, ACH ), 0.87 (s, 1H,
ACH
3
), 0.76 (s, 1H, ACH
3
),
): d = 145.2 (ANACHANA), 121.9, 121.7
ACH@CHA), 93.9 (OACH), 78.4 (NACH AO), 48.5; 48.0; 40.5;
38.7; 30.73; 25.3; 25.2; 20.3; 18.4 (bornyl ring),
1
3
C
NMR (CDCl
3
(
2
3.5. Synthesis of palladium complexes (1) and (2)
Step 1. Chiral alcohol (1.0 g; 6.0 mmol), paraformaldehyde
3.6. Suzuki–Miyaura reaction procedure
(
4
0.4 g; 10.0 mmol), MgSO (1.0 g), and hexane (10.0 mL) were
placed in dry 50 mL two necked flask equipped with a magnetic
stirrer. The flask was connected to a Wolf flask with aqueous
NaOH solution to prevent the release of excess HCl. Using a
glass capillary a gaseous hydrogen chloride (generated by
decomposition of sodium chloride with concentrated sulfuric
acid) was passed through a mixture at room temperature. The
The Suzuki–Miyaura reactions were carried out in a Schlenk
tube. Weighed amounts of the solid reactants: phenylboronic acid
135 mg; 1.1 mmol), KOH (112.0 mg; 2.0 mmol), catalyst
20.0 mg), 2-Br-toluene (0.118 mL; 1 mmol) and 5 mL of solvent
2-propanol/water mixture) were introduced to the Schlenk tube.
(
(
(
Next, the Schlenk tube was sealed with a rubber septum and intro-