Paper
Dalton Transactions
column chromatography on silica gel with dichloromethane– benzyl H3), 3.74 (s, 4H, –CH2–py), 3.62 (s, 2H, –CH2–benzyl)
methanol (8 : 1) as eluent to obtain 1.31 g (4.29 mmol, 44%) of ppm. 13C-NMR (100.6 MHz, CDCl3/TMS): δ = 158.8 (py C2),
pale yellow oil that crystallizes at 0 °C. Anal. calc. for 147.9 (py C6), 137.9 (benzyl C5), 135.4 (py C4), 127.8 and 127.2
C19H19N3O (m = 305.4 g mol−1): C, 74.8; H, 6.3; N, 13.8, found: (benzyl C1, C3, C4, C6), 126.0 (benzyl C2), 121.7 (py C3), 120.9
C, 74.7; H, 6.3; N, 13.5. 1H-NMR (400 MHz, CDCl3/TMS): δ = (py C5), 59.0 (–CH2–py), 57.4 (–CH2–benzyl) ppm.
8.45 (d, 2H, py H6), 7.63–7.55 (m, 4H, py H3 + py H4), 7.13–7.08
(m, 3H, py H5 + phenol H5), 6.90–6.86 (m, 2H, phenol H2
[Cu(I)L4-H]PF6. Under argon atmosphere, a solution of
242 mg (655 µmol) tetrakis(acetonitrile)copper(I) hexa-fluoro-
+
phenol H6), 6.70 (d, 1H, phenol H4), 3.76 (s, 4H, –CH2–py), phosphat dissolved in 8 mL acetonitrile was dropped into a
3.53 (s, 2H, –CH2–phenol) ppm. 13C-NMR (100.6 MHz, CDCl3/ solution of 200 mg (655 µmol) L4-H in 3 mL acetonitrile. The
TMS): δ = 159.4 (py C2), 157.3 (phenol C3), 148.5 (py C6), 140.1 resulting yellow solution was stirred for 30 min under nitro-
(phenol C1), 137.0 (py C4), 129.5 (phenol C5), 123.2 (py C3), gen. The solution was evaporated to dryness in vacuo and
122.3 (py C5), 120.0 (phenol C6), 116.0 (phenol C2), 114.7 151 mg (0.294 mmol, 45%) of a yellow solid was obtained.
(phenol C4), 59.6 (–CH2–py), 58.6 (–CH2–phenol) ppm.
Anal. calc. for CuC19H19N3OPF6 (m = 513.9 g mol−1): C, 44.4;
3-((Bis(pyridin-2-ylmethyl)amino)methyl)benzene-1,2-diol H, 3.7, N, 8.2, found: C; 44.2, H, 3.5; N, 8.1. MS (MALDI, m/z)
1
(L4-H2). A modification of a literature procedure was used.41
solution of 0.51 g (3.59 mmol) 2,3-dihydroxy-benzaldehyde in 2H, py H6), 7.82 (dt, 2H, py H4), 7.42–7.33 (m, 4H, py H3 + py
30 mL dried dichloromethane was treated with 0.71
H5), 7.13 (t, 1H, phenol H5), 6.90 (d, 1H, phenol H6), 6.85 (d,
A
368 [M − PF6]. H-NMR (400 MHz, CD3CN/TMS): δ = 8.56 (d,
g
(3.59 mmol) bis(2-pyridylmethyl)amine and a small amount 1H, phenol H2), 6.72 (d, 1H, phenol H4), 3.81 (s, 4H, –CH2–py),
acetic acid. The solution was stirred at ambient temperature 3.77 (s, 2H, –CH2–phenol) ppm. 13C-NMR (100.6 MHz, CD3CN/
under nitrogen atmosphere and 0.76 g (3.59 mmol) sodium TMS): δ = 157.4 (py C2), 157.3 (phenol C3), 149.5 (py C6), 138.6
triacetoxyborohydride was added in small portions. After stir- (py C4), 137.7 (phenol C1), 129.8 (phenol C5), 124.7 (py C3),
ring for 4 d at ambient temperature the dark yellow mixture 124.6 (py C5), 122.8 (phenol C6), 118.1 (phenol C2), 115.6
was acidified with 6 M HCl and then evaporated to dryness. (phenol C4), 60.4 (–CH2–phenol), 59.2 (–CH2–py) ppm.
The residue was dissolved in saturated Na2CO3 and extracted
[Cu(I)L4-H2]PF6. Under argon atmosphere, a solution of
with CHCl3 (3 × 30 mL). The combined organic phases were 174 mg (467 µmol) tetrakis(acetonitrile)copper(I) hexa-fluoro-
dried over magnesium sulphate. The solution was dried under phosphat dissolved in 10 mL acetonitrile was dropped into a
reduced pressure to yield dark yellow oil that was purified by solution of 150 mg (467 µmol) L4-H2 in 5 mL acetonitrile. The
column chromatography on silica gel with dichloromethane– resulting light yellow solution was stirred for 30 min under
methanol (8 : 1) as eluent to obtain 0.71 g (2.21 mmol, 62%) of nitrogen. The solution was evaporated to dryness in vacuo and
a pale yellow solid. Anal. calc. for C19H19N3O2 (m = 321.4 g 104 mg (0.197 mmol, 42%) of a yellow solid was obtained.
mol−1): C, 71.0; H, 6.0; N, 13.1, found: C, 71.0; H, 6.0; N, 13.0. Anal. calc. for CuC19H18N3O2PF6 (m = 528.9 g mol−1): C, 43.2;
1H-NMR (400 MHz, acetone-d6/TMS): δ = 8.41 (dq, 2H, py H6), H, 3.4; N, 8.0, found: C, 43.5; H, 3.7; N, 8.0. MS (MALDI, m/z)
1
7.60 (dt, 2H, py H4), 7.26 (d, 2H, py H3), 7.13 (dt, 2H, py H5), 384 [M − PF6]. H-NMR (400 MHz, CD3CN/TMS): δ = 8.54 (d,
6.61 (dd, 1H, phenol H4), 6.50–6.48 (m, 2H, phenol H5
+
2H, py H6), 7.81 (t, 2H, py H4), 7.40–7.35 (m, 4H, py H3 + py5),
phenol H6), 3.74 (s, 4H, –CH2–py), 3.64 (s, 2H, –CH2–phenol) 6.80 (dd, 2H, py H5), 6.61 (dd, 2H, phenol H4 + phenol H6),
ppm. 13C-NMR (100.6 MHz, acetone-d6/TMS): δ = 158.6 (py C2), 6.66 (t, 1H, phenol H5), 3.91 (s, 2H, –CH2–phenol), 3.84 (s, 4H,
148.7 (py C6), 145.8 (phenol C2), 144.9 (phenol, C3), 136.7 (py –CH2–py) ppm. 13C-NMR (100.6 MHz, CD3CN/TMS): δ = 157.7
C4), 123.3 (phenol C1), 123.1 (py C3), 122.2 (py C5), 120.9 (py C2), 149.4 (py C6), 144.9 (phenol C2), 144.6 (phenol, C3),
(phenol C6), 118.6 (phenol C5), 114.3 (phenol C4), 58.4 (–CH2– 138.4 (py C4), 124.6 (py C3), 124.4 (py C5), 122.7 (phenol C1),
py), 56.0 (–CH2–phenol) ppm.
119.8 (phenol C6), 118.9 (phenol C5), 115.6 (phenol C4), 59.1
Bis(2-pyridylmethyl)benzylamine (LH). The known synthesis (–CH2–py), 53.9 (–CH2–phenol) ppm.
for LH has been modified.27 A solution of 2.50 g (12.5 mmol)
[Cu(I)LH(CH3CN)]PF6. Under argon atmosphere, a solution
bis(2-pyridylmethyl)amine and 1.27 g (12.5 mmol) triethyl- of 73.6 mg (225 µmol) tetrakis(acetonitrile)copper(I) hexa-
amine in 50 mL tetrahydrofuran was added dropwise to a solu- fluorophosphat dissolved in 8 mL acetonitrile was dropped
tion of 2.14 g (12.5 mmol) benzyl bromide in 50 mL into a solution of 72.3 mg (250 µmol) LH in 5 mL acetonitrile.
tetrahydrofuran. The reaction mixture was stirred for 4 d at The resulting yellow solution was stirred for 10 min under
ambient temperature. The resulting white precipitate was nitrogen and reduced to 3 mL. The solution was diluted with
removed by filtration and the filtrate was dried in vacuo. The 80 mL diethyl ether to precipitate a yellow solid. The solid was
resulting yellow oil was purified by column chromatography removed by filtration and evaporated to dryness in vacuo to
on silica gel with dichloromethane–methanol (5 : 1) as eluent. obtain 74.6 mg (0.138 mmol, 67%) of a pale yellow solid. Anal.
The title compound was obtained as brown oil (2.50 g, calc. for CuC21H22N4PF6 (m = 538.9 g mol−1): C, 46.8; H, 4.1; N,
8.64 mmol, 69%). Anal. calc. for C19H19N3 (m = 289.4 g mol−1): 10.4, found: C, 46.6; H, 4.3; N, 10.8. MS (MALDI, m/z) 352
C, 78.9; H, 6.6; N, 14.5, found: C, 78.8; H, 6.7; N, 14.4. 1H-NMR [M − NCCH3PF6]. 1H-NMR (400 MHz, CD3CN/TMS): δ = 8.59
(400 MHz, CDCl3/TMS): δ = 8.44 (dq, 2H, py H6), 7.58 (td, 2H, (d, 2H, py H6), 7.84 (dt, 2H, py H4), 7.45–7.41 (m, 4H, py H3 +
py H4), 7.52 (dd, 2H, py H3), 7.34 (dd, 2H, benzyl H2, H6), 7.24 py H5), 7.36–7.30 (m, 5H, benzyl H2, H3, H4, H5, H6), 3.90 (s,
(t, 2H, py H5), 7.18–7.14 (m, 1H, benzyl H4), 7.07–7.04 (m, 2H, 2H, –CH2–benzyl), 3.85 (s, 2H, –CH2–py), 2.19 (s, 3H, –NCCH3)
Dalton Trans.
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