Organometallics
Article
protons of the guanidine moiety; 1H NMR (CDCl3, 400 MHz) δ 0.60
(t, JHH = 7.3 Hz, 3H, OCH2CH3, 6c), 0.72 (t, JHH = 6.9 Hz, 2 × 3H,
OCH2CH3, 6a/6b), 0.80 (t, JHH = 7.0 Hz, 3H, OCH2CH3, 6a), 0.87 (t,
JHH = 6.2 Hz, 2 × 3H, OCH2CH3, 6b/6c), 1.33 (t, JHH = 7.3 Hz, 2 ×
3H, OCH2CH3, 6a/6c), 1.47 (t, JHH = 7.3 Hz, 3H, OCH2CH3, 6b),
1.85, 1.89 (each s, 2 × 3H, CH3, 6a), 2.06, 2.10 (each s, 2 × 3H, CH3,
6b), 2.12, 2.17 (each s, 2 × 3H, CH3, 6c), 2.19 (s, 3H, CH3, 6b), 2.35
(s, 3H, CH3, 6a), 2.39 (s, 3H, CH3, 6c), 3.68−3.95 (m, 3 × 4H,
OCH2CH3, 6a/6b/6c), 3.99−4.07 (m, 3 × 1H, OCH2CH3, 6a/6b/
6c), 4.25−4.35 (m, 1H, OCH2CH3, 6a), 4.44 (apparent q, JHH = 5.8
Hz, 1H, OCH2CH3, 6b), 4.63 (apparent q, JHH = 5.9 Hz, 1H,
OCH2CH3, 6c), 5.76 (s, 3 × 1H, NH; 6a/6b/6c), 6.15 (t, JHH = 7.7
Hz, 1H, ArH, 6c), 6.27 (t, JHH = 7.3 Hz, 2 × 1H, ArH, 6b/6c), 6.50 (d,
JHH = 7.3 Hz, 1H, ArH, 6b), 6.60 (d, JHH = 6.6 Hz, 1H, ArH, 6a), 6.62
(s, 1H, ArH, 6a), 6.66 (t, JHH = 7.3 Hz, 3 × 1H, ArH; 6a/6b/6c), 6.71
(t, JHH = 6.6 Hz, 3 × 1H, ArH; 6a/6b/6c), 6.78−6.84 (m, 3 × 6H,
ArH; 6a/6b/6c), 6.87−6.91 (m, 3 × 2H, ArH; 6a/6b/6c), 6.94 (t, JHH
= 7.3 Hz, 3 × 1H, ArH; 6a/6b/6c), 6.98−7.03 (m, 4H, ArH; 6a (2H)/
6b (1H)/6c (1H)), 7.16 (d, JHH = 7.4 Hz, 2 × 1H, ArH, 6b/6c),
7.19−7.24 (m, 4H, ArH; 6a (2H), 6b (1H), 6c (1H)), 7.29−7.31 (m,
2 × 3H, ArH, 6b/6c), 7.34 (s, 2H, ArH, 6b), 7.36 (s, 1H, ArH, 6b),
7.42 (d, JHH = 2.2 Hz, 3H, ArH, 6a), 7.44 (d, JHH = 1.5 Hz, 3 × 2H,
revealed the presence of 7a and 7b in about 1:0.05 ratio as estimated
from the integrals of alkyl protons; H NMR (CDCl3, 400 MHz) δ
1
2.14 (s, 3H, CH3, 7a), 2.18, 2.21 (each s, 2 × 3H, CH3, 7b), 2.25, 2.28
(s, 2 × 3H, CH3, 7a), 2.29 (s, 3H, CH3, 7b), 3.36, 3.40 (each s, 2 ×
3H, C(O)OCH3, 7a), 3.43, 3.45, 3.89 (each s, 3 × 3H, C(O)OCH3,
7b), 3.99 (s, 3H, C(O)OCH3, 7a), 5.57 (d, JHH = 7.7 Hz, 1H, ArH,
7a), 5.86 (t, JHH = 7.7 Hz, 1H, ArH, 7a), 6.29 (d, JHH = 8.0 Hz, 1H,
ArH, 7b), 6.36 (t, JHH = 8.1 Hz, 1H, ArH, 7b), 6.58 (d, JHH = 7.3 Hz, 2
× 1H, ArH, 7a/7b), 6.65 (s, 2 × 1H, NH, 7a/7b), 6.77 (t, JHH = 7.3
Hz, 2 × 1H, ArH, 7a/7b), 6.83 (t, JHH = 7.3 Hz, 2 × 2H, ArH, 7a/7b),
6.90 (t, JHH = 7.3 Hz, 2 × 2H, ArH, 7a/7b), 6.94 (t, JHH = 6.2 Hz, 2 ×
1H, ArH, 7a/7b), 7.01 (d, JHH = 7.3 Hz, 2 × 1H, ArH, 7a/7b), 7.10
(d, JHH = 7.3 Hz, 2 × 1H, ArH, 7a/7b), 7.18−7.25 (br, 2 × 5H, ArH,
7a/7b), 7.27−7.29 (m, 2 × 4H, ArH, 7a/7b), 7.36−7.39 (m, 2 × 6H,
ArH, 7a/7b), 7.89 (s, 1H, NH, 7a), 7.92 (s, 1H, NH, 7b); the 13C{1H}
1
NMR signals were assigned with the aid of H−13C HETCOR NMR
spectroscopy (see Figures S25−S27 in the Supporting Information);
13C{1H} NMR (CDCl3, 100.5 MHz) δ 17.59, 18.47 (CH3), 43.78 (C),
52.03, 52.34, 55.25 (C(O)OCH3), 72.23 (C), 120.80 (CH), 122.05
(CH), 122.17 (CH), 123.42 (q, JCF = 322.3 Hz, CF3), 125.02 (CH),
125.13 (CH), 125.53 (CH), 126.09 (CH), 127.61 (CH), 127.69 (CH),
128.02 (CH), 128.23 (CH), 128.34 (CH), 128.69 (CH), 128.81 (CH),
128.87 (CH), 129.08 (CH), 129.23 (CH), 130.70 (CH), 130.86 (CH),
131.78 (C), 133.33 (C), 135.42 (C), 135.45 (C), 136.15 (C), 141.43
(C), 143.08 (C), 144.87 (C), 150.44 (C), 150.58 (C), 153.52 (C),
156.92 (C), 164.94, 171.58, 176.52 (CO); note that only 2 carbon
resonances were observed for CH3 carbons rather than the expected 3
peaks because of two overlapping peaks at δ = 17.59; MS (ESI+) m/z,
(relative intensity %), [ion] 914 (100) [M − TfOH]+. Anal. Calcd for
C53H46N3O9SF3Pd·2H2O (Mw 1064.44 + 36.03): C, 57.85; H, 4.58; N,
3.82; S, 2.91%. Found: C, 57.48; H, 4.40; N, 3.52; S, 2.69.
ArH; 6a/6b/6c), 7.48−7.52 (m, 2 × 1H, ArH, 6b/6c), 7.58 (q, JHH
=
7.8 Hz, 2 × 1H, ArH, 6b/6c), 7.70 (d, JHH = 7.3 Hz, 1H, ArH, 6c),
7.78 (dd, JHH = 8.1, 1.5 Hz, 2H, ArH, 6a), 8.09−8.12 (m, 2H, ArH,
6a), 8.20 (d, JHH = 1.4 Hz, 1H, ArH, 6c), 8.22 (br, 1H, ArH, 6c), 8.74
(s, 1H, NH, 6a), 8.94 (s, 1H, NH, 6b), 9.32 (s, 1H, NH, 6c); the
13C{1H} NMR signals were assigned with the aid of DEPT 90 and
1H−13C HETCOR NMR spectroscopy and the assignments of the
signals to 6a and 6b were made wherever possible (see Figures S19−
S24 in the Supporting Information); 13C{1H} NMR (CDCl3, 100.5
MHz, 125.3 μM) δ 13.31 (6a), 13.47 (6a), 13.73 (6b), 13.96 (6a),
14.15 (6b), 14.60 (6b) (C(O)OCH2CH3), 17.15 (6a), 17.28 (6b),
17.51 (6a/6b), 18.22 (6b), 18.31 (6a) (CH3), 59.75 (6b), 59.97 (6a),
60.63 (6b), 61.87, 62.18 (C(O)OCH2CH3), 67.95 (C, 6a), 74.90 (C,
6b), 84.62 (C), 90.85 (C), 95.92 (CH), 119.58 (CH), 121.02 (CH),
121.69 (CH), 123.16 (C), 123.45 (CH), 123.86 (CH), 124.00 (CH),
124.42 (CH), 125.02 (CH), 125.18 (CH), 125.38 (CH), 125.62 (CH),
125.75 (CH), 125.84 (CH), 125.97 (CH), 126.20 (CH), 126.57 (br,
C), 127.29 (CH), 127.67 (CH), 127.82 (CH), 127.97 (CH), 128.18
(CH), 128.37 (CH), 129.12 (C), 129.57 (CH), 129.74 (CH), 130.13
(CH), 130.24 (CH), 130.30 (C), 131.17 (CH), 131.87 (C), 132.29
(C), 132.52 (C), 133.75 (CH), 133.94 (C), 134.47 (CH), 134.84 (C),
135.41 (C), 135.91 (C), 136.36 (C), 136.82 (C), 137.16 (CH), 137.85
(C), 138.18 (C), 138.29 (C), 140.07 (C), 151.09 (C), 152.98 (C),
153.27 (C), 154.76 (C), 154.88 (C), 162.08 (6b), 163.81 (6a), 165.10
(6a), 167.89 (6a), 172.00 (6b), 174.81 (6b) (CO); note that only 5
carbon resonances were observed for CH3 carbons rather than the
expected 6 peaks because of two overlapping peaks at δ = 17.51; MS
(ESI+) m/z, (relative intensity %), [ion] 1037 (52) [M]+, 1015 (9) [M
+ Li − Et]+, 993 (9) [M − Et, Me]+, 957 (7) [M − Br]+, 935 (70) [M
+ Li − Br, Et]+, 850 (25) [M − HBr, Et, Ph]+, 834 (100) [M − EPP,
Et]+, 789 (30) [M + Li − HBr, EPP]+. Anal. Calcd for
C55H52N3O6BrPd (Mw 1037.36): C, 63.68; H, 5.05; N, 4.05%.
Found: C, 63.48/63.34; H, 5.02/4.95; N, 3.90/3.93.
Palladacycles 8a/8b. The title palladacycles were prepared from
4a/4b (100 mg, 0.096 mmol) and AgOTf (26.0 mg, 0.101 mmol) in a
mixture of CH2Cl2/acetone (1:1 (v/v), 15 mL) by a procedure
analogous to that described for 7a/7b. Yield: 77% (82 mg, 0.074
mmol). About 20% of 10a/10b·H2O (22 mg, 0.019 mmol) were also
obtained as thin red crystals from the aforementioned reaction. Data
for 8a/8b: mp (DSC) 205.2 °C; IR (KBr, cm−1) ν(NH) 3394 (w),
1
3284 (w); ν(CO) 1731 (br); ν(CN) 1598 (vs); the H NMR
spectrum of 8a/8b revealed the presence of 8a and 8b in about 1:0.29
ratio as estimated from the integrals of CH3 protons of the guanidine
1
moiety; H NMR (CDCl3, 400 MHz); δ 0.63 (t, JHH = 7.3 Hz, 3H,
OCH2CH3, 8a), 0.66 (t, JHH = 7.3 Hz, 3H, OCH2CH3, 8b), 0.76 (t,
JHH = 7.0 Hz, 3H, OCH2CH3, 8a), 0.87 (t, JHH = 7.0 Hz, 3H,
OCH2CH3, 8b), 1.38 (t, JHH = 7.0 Hz, 3H, OCH2CH3, 8b), 1.41 (t,
JHH = 7.3 Hz, 3H, OCH2CH3, 8a), 2.14 (s, 3H, CH3, 8a), 2.16, 2.18
(each s, 2 × 3H, CH3, 8b), 2.25, 2.27 (each s, 2 × 3H, CH3, 8a), 2.31
(s, 3H, CH3, 8b), 3.83−4.00 (m, 2 × 4H, OCH2CH3, 8a/8b), 4.31−
4.37 (m, 2H, OCH2CH3, 8b), 4.45−4.61 (m, 2H, OCH2CH3, 8a),
5.53 (d, JHH = 7.4 Hz, 1H, ArH, 8a), 5.84 (t, JHH = 8.1 Hz, 1H, ArH,
8a), 6.32 (d, JHH = 2.9 Hz, 1H, 8b), 6.33 (s, 1H, 8b), 6.56 (d, JHH = 7.3
Hz, 1H, 8a), 6.65−6.69 (m, 1H, 8b), 6.76 (apparent t, JHH = 6.6 Hz, 2
× 2H, 8a/8b), 6.82 (t, JHH = 8.8 Hz, 2 × 2H, 8a/8b), 6.88 (d, JHH
7.3 Hz, 2 × 2H, 8a/8b), 6.92 (d, JHH = 8.8 Hz, 1H, 8b), 6.95 (d, JHH
8.8 Hz, 1H, 8a), 7.00 (d, JHH = 7.4 Hz, 2 × 1H, 8a/8b), 7.11 (d, JHH
=
=
=
8.8 Hz, 3H, 8a (1H), 8b (2H)), 7.16 (t, JHH = 8.0 Hz, 3H, 8a (2H), 8b
(1H)), 7.21−7.25 (m, 2 × 6H, 8a/8b), 7.27−7.30 (m, 2 × 2H, 8a/
8b), 7.31−7.39 (m, 2 × 5H, 8a/8b) (NH and ArH), 7.90 (s, 1H, NH,
8a), 7.95 (s, 1H, NH, 8b); the 13C{1H} signals were assigned to 8a
and 8b wherever possible; 13C{1H} NMR (CDCl3, 100.5 MHz) δ
12.99, 13.31 (8b), 13.57, 14.79, 15.09 (8b) (OCH2CH3), 17.37 (8b),
17.60 (8a), 18.42 (8b), 18.52 (8b) (CH3), 43.88 (C, 8a), 46.23 (C,
8b), 61.05 (8a), 61.28 (8b), 61.92, 65.22 (8a), 65.38 (8a)
(OCH2CH3), 70.24 (C, 8b), 72.64 (C, 8a), 119.96, 120.75, 121.91,
122.04, 122.81, 123.46 (q, JCF = 317.2 Hz, CF3), 124.53, 124.90,
125.08, 125.49, 125.60, 125.70, 126.05, 126.15, 127.27 (br), 127.85,
127.89, 128.07, 128.10, 128.49, 128.58, 128.64, 128.69, 128.75, 128.82,
128.97, 129.09, 129.12, 129.57, 130.64, 130.69, 130.77, 130.84, 132.42,
132.47, 133.56, 133.64, 135.54, 135.66, 135.83, 136.16, 141.64, 142.28,
142.82, 143.40, 144.06, 145.00, 148.50, 149.50, 151.00, 151.11, 151.38,
Palladacycles 7a/7b. To a solution of 3a/3b (100 mg, 0.100
mmol) in a mixture of CH2Cl2/acetone (1:1 (v/v), 15 mL) was added
AgOTf (26.0 mg, 0.101 mmol) in the absence of light, and the
resulting solution was stirred at ambient temperature for 15 min.
During the course of the reaction, yellow precipitate deposited. The
reaction mixture was filtered, and the filtrate was concentrated under a
vacuum to afford a red residue. The residue was purified by
crystallization from CH2Cl2/n-hexane mixture at ambient temperature
over a period of several days to afford 7a/7b·2H2O as red cuboidal
crystals and 9a/9b·H2O as thin dark red crystals. The two types of
crystals were separated with the aid of a brush and dried under a
vacuum. Yields: 79% (87 mg, 0.079 mmol, 7a/7b·2H2O), 16% (17
mg, 0.016 mmol, 9a/9b·H2O). Data for 7a/7b·2H2O: mp (DSC)
218.99 °C; IR (KBr, cm−1) ν(NH) 3334 (br); ν(CO) 1735 (m),
1
1689 (m); ν(CN) 1592 (vs); the H NMR spectrum of 7a/7b
7590
dx.doi.org/10.1021/om4010719 | Organometallics 2013, 32, 7580−7593