Organometallics
Article
Preparation of 2-((Pyridin-2-ylmethyleneamino)methyl)phenol
(HL7). To a solution of 2-pyridinecarboxaldehyde (1.071 g, 10 mmol)
in water (10 mL) was added Na2CO3 (1.060 g, 10 mmol). Then
2-hydroxybenzylamine acetate (1.831 g, 10 mmol) in water (40 mL) was
added slowly with stirring. After the mixture was stirred overnight, a pale
yellow solid precipitated, which was collected by filtration and dried in
vacuo. Yield: 1.676 g (79%). 1H NMR (300 MHz, DMSO): δ 9.55 (br s,
1H, OH), 8.61 (s, 1H, CHN), 8.37 (s, 1H, 6-C5H4N), 7.95 (d, 1H,
4-C5H4N), 7.85 (t, 1H, 3-C5H4N), 7.43 (s, 1H, 5-C5H4N), 7.08−7.15
5.91 (s, 1H, 4-C4H3N), 5.03 (s, 2H, CH2), 3.13 (s, 18H, N(CH3)2) ppm.
13C NMR (75 MHz, C6D6): δ 150.6 (CHN), 148.1 (1-C4H3O), 147.0
(5-C4H3O), 138.3 (5-C4H3N), 127.2 (3-C4H3O), 120.7 (2-C4H3N),
112.9 (4-C4H3O), 109.6 (3-C4H3N), 101.0 (4-C4H3N), 54.4 (CH2),
46.2 (N(CH3)2) ppm. Anal. Calcd for C16H27N5OTi: C, 54.40; H, 7.70;
N, 19.82. Found: C, 53.91; H, 7.87; N, 19.51.
Preparation of Ti(L5)(NMe2)3 (C1-L5). To a solution of Ti(NMe2)4
(0.224 g, 1 mmol) in THF (2 mL) was added HL5 (0.178 g, 1 mmol) in
THF (3 mL). After the mixture was stirred at room temperature for
1 day, the solution was evaporated to dryness to give a red powder. Yield:
(2H, 3,6-C7H7O), 6.80 (2H, 4,5-C6H5O), 4.76 (s, 2H, CH2N) ppm. 13
C
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NMR (75 MHz, DMSO): δ 163.1 (CHN), 155.9, 150.0, 137.6, 130.3,
128.8 (C5H4N), 125.8, 125.5, 121.1, 119.6, 115.7 (C6H5O), 59.2
(CH2N) ppm. Anal. Calcd for C13H12N2O: C, 73.56; H, 5.70; N, 13.20.
Found: C, 73.71; H, 5.66; N, 13.15.
0.296 g (83%). H NMR (300 MHz, C6D6): δ 7.85 (s, 1H, CHN),
7.08 (s, 1H, 2-C4H3N), 6.63 (d, 1H, 4-C4H3N), 6.34 (d, 1H, 3-C4H3N),
3.68 (s, 1H, 2-C4H7O), 3.56−3.44 (2H, 5-C4H7O), 3.13 (s, 18H,
NMe2), 3.05 (s, 2H, CH2N), 1.42 (br s, 4H, 3,4-C4H7O) ppm. 13C NMR
(75 MHz, C6D6): δ 160.4 (CHN), 139.7 (2-C4H3N), 136.2 (5-C4H3N),
115.5 (3-C4H3N), 111.3 (4-C4H3N), 77.2 (CH2N), 67.4 (2-C4H7O), 60.7
(5-C4H7O), 45.6 (NMe2), 29.7 (3-C4H7O), 25.6 (4-C4H7O) ppm. Anal.
Calcd for C16H31N5OTi: C, 53.78; H, 8.74; N, 19.60. Found: C, 53.01; H,
8.45; N, 19.13.
Preparation of (NMe2)2Ti(NC(C4H3N)HC(C5H4N)HNC(C4H3N)CH-
(C5H4N)H)Ti(NMe2)2 (1). To a solution of Ti(NMe2)4 (0.448 g, 2
mmol) in THF (5 mL) was added HL1 (0.370 g, 2 mmol) in THF
(5 mL) dropwise. After the mixture was stirred at room temperature for
3 days or at 60 °C for 16 h, the solution was evaporated to dryness to give
a red solid. The red solid was washed with n-hexane and dried under
reduced pressure to yield 0.549 g (86%) of product. 1H NMR
(300 MHz, CDCl3): δ 7.82 (m, 2H, 5-C5H5N), 7.60 (m, 2H, 4-C5H5N),
7.38 (m, 2H, 3-C5H5N), 7.20 (m, 2H, 2-C5H5N), 7.16 (m, 1H,
5-C4H3N), 7.06 (m, 1H, 5-C4H3N), 6.19 (m, 2H, 4-C4H3N), 5.58 (m,
2H, 3-C4H3N), 4.39 (d, 2H, −CH−), 4.18 (d, 2H, −CH−), 3.36 (s, 12H,
N(CH3)2), 2.98 (s, 12H, N(CH3)2) ppm. Anal. Calcd for C30H42N10Ti2:
C, 56.44; H, 6.63; N, 21.94. Found: C, 55.97; H, 6.45; N, 21.96.
Preparation of 2,2′-(3,6-Bis(pyridin-2-yl)piperazine-2,5-diyl)-
diphenol (4). To a solution of Ti(NMe2)4 (0.448 g, 2 mmol) in THF
(5 mL) was added HL6 (or HL7) (0.424 g, 2 mmol) in THF (5 mL).
After the mixture was stirred at room temperature for 1 week, several
drops of water were added. The resulting mixture was stirred for 6 h, and
the precipitate was filtered away. The filtrates were washed with CH2Cl2
and dried under vacuum give a crude product. The pure yellow product
was obtained by recrystallizing or washing the crude product with a
mixture of ethanol and water. Yield: 0.255 g (60%, based on HL6); 0.225 g
Preparation of 2,5-Bis(pyridin-2-yl)-3,6-bis(1H-pyrrol-2-yl)-
piperazine (2). To a solution of 1 in THF was added several drops of
water. After the mixture was stirred at room temperature for 6 h, the
resulting precipitate was filtered. The filtrates were washed with CH2Cl2
and dried in vacuo to give a crude product. The pure red product was
afforded by recrystallizing or washing the crude product with a mixture
1
(53%, based on HL7). H NMR (300 MHz, DMSO): δ 8.48 (d, 2H,
6-C5H4N), 7.55 (t, 2H, 4-C5H4N), 7.17 (t, 2H, 3-C5H4N), 6.98 (d, 2H,
5-C5H4N), 6.93 (d, 2H, 6-C6H5O), 6.68 (d, 2H, 4-C6H5O), 6.52 (br s, 2H,
3-C6H5O), 6.42 (t, 2H, 5-C6H5O), 4.31 (s, 4H, CH) ppm. HRMS (EI): m/
z calcd for C26H24N4O2 424.1899, found 425.1973 (M + H). Anal. Calcd
for C26H24N4O2: C, 73.56; H, 5.70; N, 13.20. Found: C, 73.21; H, 5.79;
N, 13.05.
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of ethanol and water. Yield: 0.288 g (78%). H NMR (300 MHz,
DMSO): δ 10.69 (s, 2H, NH), 8.44 (d, 2H, 6-C5H4N), 7.57 (t, 2H,
4-C5H4N), 7.17 (t, 2H, 3-C5H4N), 7.10 (d, 2H, 5-C5H4N), 6.50 (s, 2H,
5-C4H3N), 5.73 (s, 2H, 3-C4H3N), 5.67 (s, 2H, 4-C4H3N), 4.12 (t, 2H,
CH), 4.21 (t, 2H, CH) ppm. 13C NMR (75 MHz, DMSO): δ 159.8,
148.3, 135.8, 122.9, 122.0, 116.3, 106.5, 105.2 (Ar), 65.1 (CH), 57.6
(CH) ppm. HRMS: m/z 371.1978 (M + 1). Anal. Calcd for C22H22N6:
C, 71.33; H, 5.99; N, 22.69. Found: C, 71.41; H, 6.06; N, 22.44.
Preparation of Ti(L2)2 (C-L2). To a solution of Ti(NMe2)4 (0.224 g,
1 mmol) in THF (2 mL) was added H2L2 (0.200 g, 1 mmol) in THF
(3 mL). After the mixture was stirred at room temperature for 2 days,
the solution was evaporated to dryness to give a red solid. The red solid
was washed with n-hexane and dried under reduced pressure to yield
0.167 g (75%) of product. 1H NMR (300 MHz, CD2Cl2): δ 8.92 (s, 1H,
CHN), 7.72 (d, 2H, 3-C6H4O), 7.56 (t, 2H, 6-C6H4O), 7.09 (t, 2H,
4-C6H4O), 6.72 (d, 2H, 5-C6H4O), 6.40 (s, 2H, 5-C4H3N), 5.84 (s, 2H,
4-C4H3N), 5.74 (s, 2H, 3-C4H3N), 5.53−5.19 (4H, CH2) ppm. Anal.
Calcd for C24H20N4O2Ti: C, 64.88; H, 4.54; N, 12.61. Found: C, 64.64;
H, 4.63; N, 12.42.
Preparation of Ti(L3)(NMe2)3 (C1-L3). To a solution of Ti(NMe2)4
(0.224 g, 1 mmol) in THF (2 mL) was added HL3 (0.184 g, 1 mmol) in
THF (3 mL). After the mixture was stirred at room temperature
overnight, the solution was evaporated to dryness to yield 0.334 g
(92%) of product. 1H NMR (300 MHz, C6D6): δ 7.29 (s, 1H, CHN),
7.87(s, 2H, −C6H5), 6.77 (d, 2H, −C6H5), 6.66 (s, 2H, 5-C4H3N,
−C6H5), 6.37 (s, 1H, 3-C4H3N), 6.14 (s, 1H, 4-C4H3N), 3.89 (s, 2H,
−CH2−), 2.80 (d, 18H, −N(CH3)2). 13C NMR (75 MHz, C6D6): δ 158.6
(CHN), 139.2, 137.7, 136.4, 129.1, 128.1, 127.1, 115.6, 111.3 (C4H3N,
Ph), 60.1 (CH2), 45.1 (N(CH3)2) ppm. Anal. Calcd for C18H29N5Ti: C,
59.50; H, 8.05; N, 19.28. Found: C, 58.88; H, 7.68; N, 19.85.
ASSOCIATED CONTENT
* Supporting Information
Text, tables, figures, and CIF files giving X-ray crystallographic
data, NMR spectroscopic data, and computational results. This
material is available free of charge via the Internet at http://pubs.
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AUTHOR INFORMATION
Corresponding Author
Notes
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The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
We appreciate the financial support of the Hundreds of Talents
Program (2005012) of CAS, the Natural Science Foundation of
China (20872105 and 21002073), the “Qinglan Project” of
Jiangsu Province (Bu109805), and A Project Funded by the
Priority Academic Program Development of Jiangsu Higher
Education Institutions. Y.X. thanks the High Performance
Computation Platform of Wenzhou University for providing
the computation facility.
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Preparation of Ti(L4)(NMe2)3 (C1-L4). To a solution of Ti(NMe2)4
(0.224 g, 1 mmol) in THF (2 mL) was added HL4 (0.174 g, 1 mmol) in
THF (3 mL). After the mixture was stirred at room temperature for
1 day, the solution was evaporated to dryness to give a red powder. Yield:
0.265 g (75%). 1H NMR (300 MHz, C6D6): δ 7.81 (s, 1H, CHN),
7.04 (s, 1H, 5-C4H3O), 6.83 (s, 1H, 5-C4H3N), 6.57 (s, 1H, 3-C4H3O),
6.32 (s, 1H, 3-C4H3N), 6.20 (s, 1H, 3-C4H3O), 6.19 (s, 1H, 4-C4H3O),
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dx.doi.org/10.1021/om300022u | Organometallics 2012, 31, 6005−6013