Inorganic Chemistry
Article
pyridinecarboxaldehyde (0.27 mL, 2.83 mmol), and an chloroform/
liquid N2 cooling bath ((−63 °C). Work up gave a light yellow solid
which was dried under a vacuum to afford a mixture of syn- and anti-
mCB-L1 (369.6 mg, 1.03 mmol, 79.3%), mp 145−150 °C. IR (ATR;
selected bands): ν 3379 (OH), 2613, 2595, 2554 (BH). MALDI TOF:
359.10 [M + H]+. NMR of the diastereoisomer mixture in various
solvents:
CHOH for syn- or anti-mCB-Pd1 isomer). 11B NMR (DMSO-d6):
−11.4 (br m). 13C NMR (DMSO-d6): 162.24, 161.16, 160.96, 157.81,
155.76, 154.69, 139.74, 139.53, 139.40, 127.32, 124.22, 123.58, 122.88,
122.61 (s, NC5H4), 76.11, 75.74, 75.35, 74.47, 73.92, 73.75 (s, CHOH
and CHB10H9).
Suzuki Coupling with Arylboronic Acids in the Presence of
(oCB-L1)Pd. General Procedure. A screw-capped tube equipped
with a magnetic stirrer bar was charged with the aryl- or benzyl
bromide (1 mmol), arylboronic acid (1.5 mmol), potassium carbonate
(276 mg, 2.0 mmol), and (oCB-L1)Pd (0.00049 mg, 10−6 mmol) and
distilled water (1 mL) at room temperature. This mixture was heated
to 110 °C for 10 h under stirring, allowed to cool, and extracted with
diethyl ether (4 × 5 mL). The combined organic extracts were dried
over anhydrous sodium sulfate and evaporated in vacuo to give a
residue that was purified by flash column chromatography using
hexane:ethyl acetate as eluent. By this procedure the following biaryls
and diarylmethanes were prepared:
1
(Ac-d6). H NMR: 8.51 (d, J = 3.0, 1H, C5H4N), 7.81 (td, J = 9.0
and 3.0, 1H, C5H4N), 7.42 (d, J = 6.0, 1H, C5H4N), 7.36(td, J = 6.0
and 3.0, 1H, C5H4N),5.40 (d, J = 6.0, 1H, OH), 4.96 (d, J = 6.0, 1H,
1
CHOH). H {11B} NMR (Ac-D6): Only signals due to B−H protons
are given: 2.73 (br s, 2H), 2.19 (br s, 2H), 2.15 (br s, 3H), 1.88 (br s,
3H); 11B NMR: −5.34 (br s, 2B), −10.61 (br s, 6B), −12.98 (br s,
2B). 13C NMR: 160.17 (s, NC5H4), 148.99 (s, NC5H4), 137.42 (s,
NC5H4), 124.43 (s, NC5H4), 122.83 (s, NC5H4), 82.45 (s, cluster
Carbons), 75.31 (s, CHOH).
(DMSO-d6). 1H NMR: 8.45 (d, J = 5.0 Hz, 2H, C5H4N), 7.80 (t, J =
7.4, 1.5, 2H, C5H4N), 7.35 (d, J = 8.0, 2H, C5H4N), 7.30 (dd, J = 7.5,
4.7, 2H, C5H4N), 6.50 (d, J = 5.7, 2H, OH), 4.80 (d, J = 5.3, 2H,
CHOH). 1H{11B} NMR: Only signals due to B−H protons are given:
2.60 (br s, 2H), 2.06 (br s, 6H), 1.79 (br s, 2H). −5.13 (br s, 2B),
−10.66 (br s, 6B).
4-Acetyl-4′-methoxybiphenyl41 (99%). H NMR (CDCl3) δ: 2.63
1
(s, 3H), 3.86 (s, 3H), 7.01 (d, J = 8.8 Hz, 2H), 7.57 (d, J = 8.8 Hz,
2H), 7.65 (d, J = 8.4 Hz, 2H), 7.99 (d, J = 8.4 Hz, 2H). 13C NMR
(CDCl3) δ 26.6, 55.3, 114.4, 126.6, 128.3, 128.9, 132.2, 135.2, 145.3,
159.9, 197.7
4-Acetylbiphenyl42 (99%). H NMR (CDCl3) δ: 8.03 (d, J = 8.0
1
Synthesis of [(oCB-L1)PdCl] ((oCB-L1)Pd). oCB-L1 (100 mg, 0.28
mmol) and PdCl2(MeCN)2 (61 mg, 0.28 mmol) were dissolved in
acetone (10 mL) in a capped vial. The reaction mixture was stirred
under air at room temperature for 15 h. Then a yellowish precipitate
was collected by centrifugation (6000 rpm, 10 min), washed with
acetone (3 × 3 mL) to remove excess of starting materials, and dried
under a vacuum to provide pure (oCB-L1)Pd (100 mg, 0.2 mmol,
71%) as a pale yellow solid; dec pt 283 °C. Elemental analysis
calculated for C14B10H21N2O2ClPd·H2O: C 32.50%, H 4.48%, N
5.42%; found C 32.52%, H 4.20%, N 5.42%. MALDI-TOF, m/z: M:
462.45 [M − Cl-H]+. IR (ATR; selected bands): ν 3344, 3316 (OH),
2617, 2594, 2567, 2553 (BH). 1H NMR (DMSO-d6): δ = 8.92 (d, J =
4.9, 2H, NC5H4), 8.14 (t, J = 7.6, 2H, NC5H4), 7.90 (d, J = 7.3, 2H,
NC5H4), 7.55 (t, J = 6.7, 2H, NC5H4), 7.45 (BR s, 2H, CHOH), 6.09
(BR s, 2H, CHOH); 1H{11B} NMR (DMSO-d6): Only signals due to
B−H protons are given: 2.75 (br s, 1H), 2.17 (br s, 3H), 1.86 (br s,
Hz, 2H), 7.68 (d, J = 8.0 Hz, 2H), 7.62 (d,J = 7.6 Hz, 2H), 7.47 (t, J =
7.6 Hz, 2H), 7.41 (d, J = 7.6 Hz, 1H), 2.65 (s, 3H). 13C NMR
(CDCl3): δ 197.7, 145.7, 139.8, 135.8, 128.9, 128.8, 128.2, 127.2,
127.1, 26.7.
4-Methoxybiphenyl21 (84%). H NMR (CDCl3) δ: 7.56−7.51 (m,
1
4H), 7.41 (t, J = 7.6 Hz, 2H), 7.30 (t, J = 7.6 Hz, 1H), 6.98 (d, J = 7.2
Hz, 2H), 3.85 (s, 3H). 13C NMR (CDCl3) δ: 159.1, 140.8, 133.7,
128.7, 128.1, 126.7, 126.6, 114.2, 55.3.
2-Chloridebiphenyl21 (91%). H NMR (CDCl3) δ: 7.48−7.38 (m,
1
6H), 7.36−7.26 (m, 3H). 13C NMR (CDCl3) δ: 140.5, 139.4, 132.5,
131.4, 129.9, 129.4, 128.5, 128.0, 127.6, 126.8.
2-Chloro-3′,4′-dimethoxy-1,1′-biphenyl43 (77%). 1H NMR
(CDCl3) δ: 3.87, 3.89 (2s, 6H), 6.94 (d, J = 8.4 Hz, 1H), 7.08 (d, J
= 2.0 Hz, 1H), 7.12 (dd, J = 8.2, 2.2 Hz, 1H), 7.39−7.52 (m, 4H). 13C
NMR (CDCl3) δ: 148.6, 148.4, 140.3, 132.6, 132.1, 131.4, 130.0,
128.3, 126.8, 121.8, 112.9, 110.8, 56.0, 55.9.
3H), 0.39 (br s, 2H); 11B NMR (DMSO-d6): +10 to −20 (br m). 13
C
5-Chloro-2-methoxy-1,1′-biphenyl44 (66%). H NMR (CDCl3) δ:
1
NMR (DMSO-d6): 161.01 (s, NC5H4), 153.39 (s, NC5H4), 139.65 (s,
NC5H4), 124.49 (s, NC5H4), 123.52 (s, NC5H4), 89.93 (s, CHOH),
72.37 (s, CHB10H9).
7.52 (m, 2H), 7.37 (m, 5H), 6.92 (d, J = 8.4 Hz, 1H), 3.81 (s, 3H).
13C NMR (CDCl3) δ: 155.9, 155.1, 137.1, 132.4, 130.4, 129.3, 128.1,
128.05, 127.4, 125.7, 112.5.
Synthesis of [(oCB-L2)PdCl] ((oCB-L2)Pd). The reaction procedure
of (oCB-L1)Pd was followed, using oCB-L2 (10 mg, 0.028 mmol),
[PdCl2(MeCN)2] (6.1 mg, 0.028 mmol), and acetone (3 mL), under
air at 55 °C for 50 h. Work up gave (oCB-L2)Pd as an impure white
solid. Recrystallization from DMF gave single crystals suitable for X-
ray diffraction measurements. MALDI-TOF, m/z: M: 491.52 [M]+. 1H
NMR (DMSO-d6): 8.02 (t, J = 7.8, 2H, C5H3N), 7.71 (d, J = 7.2, 2H,
C5H3N), 7.51 (d, J = 7.3, 2H, C5H31N), 7.45 (br s, 2H, OH), 6.18 (br s,
2H, CHOH), 3.15 (s, 6H, CH3). H {11B} NMR (DMSO-d6): Only
signals due to B−H protons are given: 2.77−2.12 (br m, overlapped
with residual solvent), 1.84 (br s, 3H), 0.24 (br s, 2H); 11B NMR
(DMSO-d6): −2.41 (br s, 10B) 5 to −20 (br m).13C NMR (DMSO-
d6): 160.28 (s, C5H3N), 153.27 (s, C5H3N), 139.41 (s, C5H3N),
124.97 (s, C5H3N), 120.55 (s, C5H3N), 90.38 (s, cluster carbon),
71.89 (s, CHOH), 27.02 (s, CH3).
Synthesis of [(mCB-L1)PdCl] ((mCB-L1)Pd). The reaction
procedure of (oCB-L1)Pd was followed, using mCB-L1 (10 mg,
0.028 mmol), [PdCl2(MeCN)2] (6.1 mg, 0.028 mmol) and acetone (3
mL), under air at 55 °C for 2 h. Work up gave pure (mCB-L1)Pd
(10.6 mg, 0.021 mmol, 76.1%) as a light yellow solid; dec pt 282 °C.
Elemental analysis calculated for C14B10H21N2O2ClPd·DMF: C
35.67%, H 4.93%, N 7.34%; found C 35.76%, H 5.08%, N 7.10%.
MALDI-TOF, m/z: M: 462.49 [M − Cl-H]+. IR (ATR; selected
bands): ν 3412, 3178 (OH), 2603 (BH). 1H NMR (DMSO-d6):
10.02, 9.91, 9.82, and 9.68 (d, J = 5.7, 2H, C5H3N for four
diasteromers), 8.10−7.49 (m, 6H, C5H3N), 7.08, 7.07, 6.91, and 6.83
(d, J = 5.9, 2H, OH for for four diasteromers), 5.14 (d, J = 5.9, 1H,
CHOH for anti- or syn-mCB-Pd1 isomer), 4.96 (d, J = 5.3, 1H,
1-Benzyl-4-methoxybenzene45 (82%). H NMR (CDCl3) δ: 3.81
1
(s, 3H), 3.96 (s, 2H), 6.86 (d, J = 8.5 Hz, 2H), 7.18 (d, J = 8.5 Hz,
2H), 7.24−7.29 (m, 3H), 7.32 (t, J = 7.3 Hz, 2H). 13C NMR (CDCl3)
δ: 41.2, 55.4, 114.0, 126.1, 128.6, 129.0, 130.0, 133.4, 141.7, 158.1.
1-Benzylnaphthalene46 (99%). 1H NMR (CDCl3) δ: 4.53 (s, 2H),
7.24−7.31 (m, 3H), 7.32−7.40 (m, 3H), 7.47−7.56 (m, 3H), 7.85 (d, J
= 8.4 Hz, 1H), 7.91−9.97 (m, 1H), 8.05−8.12 (m, 1H).13C NMR
(CDCl3) δ: 39.2, 124.4, 125.7, 126.1, 126.2, 127.5, 127.5, 128.6, 128.8,
128.9, 132.3, 134.1, 136.8, 140.8.
1-Benzyl-3,5-difluorobenzene47 (87%). H NMR (CDCl3) δ: 7.33
1
(tt, J = 8.2, 1.6 Hz, 2H), 7.25 (tt, J = 6.2, 1.4 Hz, 1H), 7.20−7.17 (m,
2H), 6.74−6.68 (m, 2H), 6.65 (tt, J = 9.0, 2.3 Hz, 1H), 3.96 (s, 2H).
13C NMR (CDCl3) δ: 163.0 (dd, JC−F = 248.0, 12.9 Hz), 145.0 (t, JC−F
= 8.9 Hz), 139.4, 128.9, 128.7, 126.6, 111.6 (dd, JC−F = 18.4, 6.5 Hz),
101.6 (t, JC−F = 25.4 Hz), 41.6 (t, JC−F = 1.9 Hz). 19F NMR (376 MHz,
CDCl3) δ: −110.3 (m, 2F)
4-Benzyl-1,2-dimethoxybenzene48 (99%). 1H NMR (CDCl3) δ:
3.84−3.87 (2 s, 6H), 3.96 (s, 3H), 6.74−6.83 (m, 3H), 7.20−7.34 (m,
5H). 13C NMR (CDCl3) δ: 41.4, 55.7, 55.8, 111.1, 111.2, 112.2, 120.7,
120.8,125.9, 128.3, 128.6, 133.5, 141.2, 147.3, 148.8.
Suzuki Coupling with Potassium Phenyltrifluoroborate in
the Presence of (oCB-L1)Pd. General Procedure. A screw-capped
tube equipped with a magnetic stirrer bar was charged with the aryl
bromide (1 mmol), potassium phenyltrifluoroborate (276 mg, 1.5
mmol), potassium carbonate (276 mg, 2.0 mmol), and (oCB-L1)Pd
(0.00049 mg, 10−6 mmol) and distilled water (1 mL) at room
temperature. This mixture was heated to 110 °C for 10 h under
J
dx.doi.org/10.1021/ic5013999 | Inorg. Chem. XXXX, XXX, XXX−XXX