Versatile methods for preparation of new cyclometalated gold(III) complexes

Article abstract of DOI:10.1021/om300537a

Versatile methods for the high-yield syntheses of new cyclometalated gold(III) complexes are described. Mono- or dialkylated or arylated gold(III) complexes are selectively obtained from reaction of Au(OCOCF₃) ₂(tpy) (tpy = 2-(p-toly

Full text of DOI:10.1021/om300537a

Versatile Methods for Preparation of New
Cyclometalated Gold(III) Complexes
a
a
b
c,
Eirin Langseth, Carl Henrik Görbitz, Richard H. Heyn, and Mats Tilset *
a
b
Department of Chemistry, University of Oslo, P.O. Box 1033 Blindern, 0315 Oslo, Norway,
c
SINTEF Materials and Chemistry, P.O. Box 124, Blindern, 0314 Oslo, Norway, Centre for
Theoretical and Computational Chemistry (CTCC), Department of Chemistry, University of Oslo,
P.O. Box 1033 Blindern, 0315 Oslo, Norway.
Corresponding author: mats.tilset@kjemi.uio.no
Supporting Information
General Experimental Methods
Compound 1
2
3
Compound 2
4
Compound 3
5
Compound 4
6
Compound 5
7
Compound 6
8
Compound 7
9
1
19
13
19
1
H, F, C, COSY, NOESY and F- H HOESY NMR spectra
10
38
39
46
Crystallographic Methods
Compound 1 Crystallographic Data
Compound 2 Crystallographic Data
1

General Experimental Methods. MeLi, PhLi, MeMgBr, EtMgBr and PhMgBr were purchased
from Sigma-Aldrich and used as received. TFA and NMR-solvents were used as received. CH Cl
and THF were dried by use of the solvent purification system MB SPS-800 from MBraun.
AuCl (tpy) was prepared as previously reported (Shaw, A. P.; Tilset, M.; Heyn, R. H.; Jakobsen, S.
2
2
2
J. Coord. Chem. 2011, 64, 38-47). All reactions were performed with magnetic stirring, including
microwave reaction. The microwave oven used was of the type Milestone MicroSYNTH with a
rotor of the type SK-10. All reactions were performed under argon, except when performed in the
3
microwave. In the Grignard reactions neutral distilled water neutralized with NaHCO was used for
washing,. Elemental analyses were performed by School of Chemistry, University of Birmingham,
England (compounds 1 and 2) and Mikroanalytisches Laboratorium Kolbe, Mülheim an der Ruhr,
Germany (compounds 3-6). NMR spectra were recorded on a Bruker Avance DPX200 operating at
1
1
1
2
00 MHz ( H), DPX300 operating at 300 MHz ( H) and AVII400 operating on at 400 MHz ( H).
1
9
3 6 6 3
F has been referenced to CFCl by using C F (-164.9 ppm with respect to CFCl at 0 ppm) as an
1
internal standard. H NMR assignments were made on the basis of COSY and NOESY experiments
and refer to the numbering schemes shown below. Mass spectrometry was performed with Waters
ProSpec (EI) and Q-TOF-2 (ESI) instruments.
4
3
3'
4'
4
3
3'
4'
5
5
N
N
6
o'
6'
6
6'
Au
Au
Br
m'
o
o
p
p
p'
m
m
2

3 2
Compound 1: Au(OCOCF ) (tpy)
A solution of Au(OAc) (0.384 g, 1.03 mmol, 1.00 equiv.) and 2-(p-tolyl)pyridine (186 ꢀL, 1.09
3
mmol, 1.06 equiv.) in a 1:1 mixture of water (15.0 mL) and trifluoroacetic acid (15.0 mL) was
heated in the microwave oven at 120 ⁰C for 30 min. After the reaction, the light yellow solution was
cooled at room temperature for 15-30 min and then decanted over to an Erlenmeyer flask. If the
product had started to precipitate out, TFA was added to redissolve the product before decanting, in
3
order to remove a small amount of unreacted Au(OAc) . The product can be precipitated by either
addition of water (20-50 mL), by cooling to 0 °C, or by combined water addition and cooling. The
precipitate was collected on a fine frit and washed with water (3 x 5 mL) and diethyl ether (5 mL)
and dried under a stream of air for 30-40 min. The product was obtained in 94 % yield (0.572 g).
1
H NMR (400 MHz, CD Cl ): δ 8.42 (d, 6-CH, J = 5.8 Hz, 1H), 8.19 (t, 4-CH, J = 7.7 Hz, 1H),
2
2
7
.92 (d, 3-CH, J = 8.0 Hz, 1H), 7.50-7.42 (m, 5,3´-CH, 2H), 7.23 (d, 4´-CH, J = 7.8 Hz, 1H), 6.71
(
s, 6´-CH, 1H), 2.37 (s, ArCH , 3H).
3
1
3
C NMR (75 MHz, CDCl
and CO signals, coupling to F was not observed).
F NMR (377 MHz, CD Cl ): δ -76.1 (s, CF (trans to N), 3F), -77.0 (s, CF
MS (ESI in CH
3
): δ 165.0, 147.7, 144.3, 144.2, 142.7, 138.2, 131.2, 129.1, 125.9, 124.2,
19
1
21.5, 22.4 (For the CF
3
1
9
2
2
3
3
(cis to N), 3F).
+
+
+
3
CN): m/z = 859.1, 614.1 (63 % [M+Na ] ), 478.1 (100 % [M-OCOCF
3
] ).
MS-HR (CH CN): 614.0067, calculated for C H AuF NNaO 614.0077 (-1.68 ppm).
3
16 10
6
4
6 4
Anal. Calcd for C16H10AuF NO : C, 32.51; H, 1.7; N, 2.37. Found: C, 32.69; H, 1.61; N, 2.48.
3

2
Compound 2: AuMe (tpy)
A solution of Au(OCOCF
cooled in a dry ice/acetone bath and then MeLi (1.6 M in Et
was added. No change in color was observed upon addition. The reaction was stirred for 1 h at -78
C and then allowed to warm up to rt. The solution turned purple upon warming up. THF was
removed in vacuo. The resulting solid was dissolved in dry CH Cl and filtered through Celite to
3
)
2
(tpy) (1) (0.150 g, 0.253 mmol, 1.00 equiv.) in THF (5.0 mL) was
2
O, 0.560 mL, 0.896 mmol, 3.54 equiv.)
°
2
2
2 2
give a light yellow solution. In case of a continued purple solution, filter solution again. CH Cl was
removed in vacuo to give a white powder of compound 2 (0.093 g, 93 %)
AuMe
2
(tpy) (2) could also be synthesized from AuCl
2
(tpy) (0.104 g, 0.239 mmol, 1.00 equiv.) and
MeLi (1.6 M in Et
2
O, 0.500 mL, 0.800 mmol, 3.34 equiv) using the same procedure (except stirring
at -78 °C for 3.5 h), yielding 0.085 g (89 %) of 2.
1
H NMR (400 MHz, CDCl
´-CH, J = 7.9 Hz, 1H), 7.56 (s, 6´-CH, 1H), 7.30-7.24 (m, 5-CH, 1H), 7.07 (dd, 4´-CH, J = 7.9, 1.0
Hz, 1H), 2.41 (s, ArCH , 3H), 1.38 (s, AuCH (trans to N), 3H), 0.44 (s, AuCH (cis to N), 3H).
): δ 173.2, 167.4, 146.5, 143.8, 141.0, 139.7, 132.9, 126.6, 124.7,
3
): δ 8.68 (d, 6-CH, J = 5.5 Hz, 1H), 7.98-7.81 (m, 3,4-CH, 2H), 7.67 (d,
3
3
3
3
1
3
C NMR (101 MHz, CDCl
22.4, 119.8, 22.1, 13.2, 1.6.
3
1
+
+
MS (EI in CH
MS-HR (CH CN): 395.093983, calculated for C14
Anal. Calcd for C H AuN: C, 42.54; H, 4.08; N, 3.54. Found: C, 42.27; H, 3.99; N, 3.48.
3
CN): m/z = 395 (11 % [M] ), 380 (84 % [M-Me] ), 182 (100 %).
3
H
16AuN 395.094835 (+2.2 ppm).
1
4
16
4

2
Compound 3: AuPh (tpy)
A solution of Au(OCOCF ) (tpy) (1) (0.154 g, 0.261 mmol, 1.00 equiv.) in THF (5.0 mL) was
3
2
2
cooled in a dry ice/acetone bath and then PhLi (1.8 M in Et O, 0.490 mL, 0.896 mmol, 3.39 equiv.)
was added. The solution turned orange upon addition. The reaction was stirred for 1 h at -78 °C and
then was warmed up to rt. THF was removed in vacuo. The resulting brown oil was dissolved in dry
CH
2
Cl
2
and filtered through Celite to give a light brown solution. In case of a continued purple
Cl was removed in vacuo and gave a brown powder
solution, the solution was filtered again. CH
2
2
(0.126 g, 93 %)
AuPh
2
(tpy) (3) could also be synthesized from AuCl
2
(tpy) (0.101 g, 0.231 mmol, 1.00 equiv.) and
PhLi (1.8 M in Et
2
O, 0.450 mL, 0.810 mmol, 3.51 equiv) using the same procedure (except stirring
at -78 °C for 2 h), yielding 0.096 g (80 %) of 3.
1
H NMR (400 MHz, CD
d, 3´-CH, J = 7.9 Hz, 1H), 7.48 (d, o´-CH, J = 7.3 Hz, 2H), 7.43 (d, o-CH, J = 7.6 Hz, 2H), 7.23 (t,
m´-CH, J = 7.3 Hz, 2H), 7.18-7.11 (m, m,5-CH, 3H), 7.09-7.01 (m, p,p´,4´-CH, 3H), 6.82 (s, 6´-
CH, 1H), 2.21 (s, ArCH , 3H).
C NMR (101 MHz, CD Cl
2 2
Cl ): δ 8.09 (d, 6-CH, J = 5.3 Hz, 1H), 7.97-7.84 (m, 3,4-CH, 2H), 7.70
(
3
1
3
2
2
): δ 169.8, 167.9, 167.3, 149.6, 143.9, 142.8, 141.8, 140.9, 137.0,
1
35.8, 133.0, 129.3, 129.3, 127.6, 125.2, 124.7, 124.7, 123.4, 120.4, 22.2.
+
MS (ESI in CH
MS-HR (CH CN): 558.0880, calculated for C24
Anal. Calcd for C H AuN: C, 55.50; H, 3.88; N, 2.70. Found: C, 55.69; H, 4.01; N, 2.51.
3
CN): m/z = 558.1 (100 % [M+K] ).
3
H20AuKN 558.0898 (-3.30 ppm).
2
4
20
5

Compound 4: AuBrMe(tpy)
A solution of Au(OCOCF
3
)
2
(tpy) (1) (0.100 g, 0.169 mmol, 1.00 equiv.) in THF (10.0 mL) was
O, 0.080 mL, 0.240 mmol, 1.42 equiv.)
cooled in a dry ice/acetone bath and MeMgBr (3.0 M in Et
2
was added. The solution formed an off-white, milky suspension shortly after addition. The reaction
was stirred for 1 h at -78 °C and then at rt for 1 h. While warming to ambient temperature, the
reaction cleared up to a light yellow solution. THF was removed in vacuo. The resulting off-white
solid was dissolved in CH
2
Cl
2
(25 mL) and washed with distilled water (pH=7, 3 x 25 mL), and the
and filtered through
organic phase turned slightly purple. The organic phase was dried over MgSO
4
Celite to give a light yellow solution and solvent was removed in vacuo to yield 4 as an off-white
powder, 0.068 g (87 %).
Compound 4 could be synthesized from AuCl
2
(tpy), but was not isolated. AuCl
2
(tpy) (0.076 g,
0
.175 mmol, 1.00 equiv.) and MeMgBr (3.0 M in Et
2
O, 0.170 mL, 0.510 mmol, 2.92 equiv) using
1
the same procedure. The H NMR spectrum is shown.
1
H NMR (400 MHz, CD
2
Cl
H), 7.91 (d, 3-CH, J = 8.0 Hz, 1H), 7.68 (d, 3´-CH, J = 7.9 Hz, 1H), 7.45-7.42 (m, 5-CH, 1H),
.32 (s, 6´-CH, 1H), 7.20 (d, 4´-CH, J = 8.0 Hz, 1H), 2.43 (s, ArCH , 3H), 1.62 (s, AuCH , 3H).
C NMR (101 MHz, CD Cl ): δ 162.2, 149.2, 147.9, 142.4, 141.8, 141.1, 130.5, 128.9, 125.9,
2
): δ 9.53 (d, 6-CH, J = 5.4 Hz, 1H), 7.98 (td, 4-CH, J = 7.7, 1.5 Hz,
1
7
3
3
1
3
2
2
1
24.5, 120.0, 22.2, 8.4, 1.3.
8
1
+
79
+
81
MS (EI in CH CN): m/z = 460.9 (10 % [M( Br)] ), 458.9 (11 % [M( Br)] ), 445.9 (9 % [M( Br)-
3
+
79
+
+
+
Me] ), 443.9 (9 % [M( Br)-Me] ), 380.0 (55 % [M-Br] ), 365.0 (9 % [M-Br-Me)] ), 182.0 (100%).
7
9
MS-HR (CH
3
CN): 458.990018, calculated for C13H13Au BrN 458.989696 (-0.7 ppm).
Anal. Calcd for C H AuBrN: C, 33.93; H, 2.85; N, 3. 40. Found: C, 33.91; H, 2.87; N, 3.03.
1
3
13
6

Compound 5: AuBrEt(tpy)
A solution of Au(OCOCF ) (tpy) (1) (0.101 g, 0.171 mmol, 1.00 equiv.) in THF (10.0 mL) was
3
2
cooled in a dry ice/acetone bath and then EtMgBr (3.0 M in Et
equiv.) was added. No color change was observed upon addition. The reaction was stirred for 1 h at
78 °C and then at rt for 1 h. During warming to rt, the reaction cleared up to a light yellow
solution. THF was removed in vacuo. The resulting off-white solid was dissolved in CH Cl (25
mL) and washed with distilled water (pH=7, 3 x 25 mL), and the organic phase turned slightly
purple. The organic phase was dried over MgSO and filtered through Celite to give a light yellow
2
O, 0.080 mL, 0.240 mmol, 1.41
-
2
2
4
solution and solvent was removed in vacuo to yield 5 as a light yellow powder, 0.053 g (66 %).
1
H NMR (400 MHz, CD
2
Cl
H), 7.91 (d, 3-CH, J = 7.9 Hz, 1H), 7.69 (d, 3´-CH, J = 7.9 Hz, 1H), 7.46-7.39 (m, 5,6´-CH, 2H),
.20 (d, 4´-CH, J = 8.4 Hz, 1H), 2.53 (q, AuCH , J = 7.6 Hz, 2H), 2.46 (s, ArCH , 3H), 1.40 (t,
2
): δ 9.48 (d, 6-CH, J = 4.8 Hz, 1H), 7.96 (td, 4-CH, J = 7.7, 1.6 Hz,
1
7
2
3
CH CH , J = 7.6 Hz, 3H).
2
3
1
3
C NMR (101 MHz, CD
2 2
Cl ): δ 161.9, 149.4, 149.4, 142.7, 141.7, 141.0, 130.7, 128.8, 125.7,
1
24.3, 120.0, 27.7, 22.3, 16.6.
8
1
+
79
+
81
3
MS (EI in CH CN): m/z = 475.0 (2 % [M( Br)] ), 473.0 (2 % [M( Br)] ), 445.9 (10 % [M( Br)-
+
79
+
+
+
Et] ), 443.9 (11 % [M( Br)-Et] ), 394.0 (7 % [M-Br] ), 365.0 (12 % [M-Et-Br] ), 196 (100 %).
7
9
MS-HR (CH
3
CN): 473.005165, calculated for C14
H15Au BrN 473.005346 (+0.4 ppm).
Anal. Calcd for C14
H15AuBrN: C, 35.46; H, 3.19; N, 2. 95. Found: C, 35.36; H, 3.19; N, 2.87.
7

Compound 6: AuBrPh(tpy)
A solution of Au(OCOCF ) (tpy) (1) (0.100 g, 0.169 mmol, 1.00 equiv.) in THF (10.0 mL) was
3
2
cooled in a dry ice/acetone bath and then PhMgBr (1.0 M in THF, 0.350 mL, 0.350 mmol, 2.07
equiv.) was added. No color change was observed upon addition. The reaction was stirred for 1 h at
-
78 °C and then at rt for 1 h. The solution was light yellow. THF was removed in vacuo. The
resulting white solid was dissolved in CH Cl (25 mL) and washed with distilled water (pH=7, 3 x
5 mL), and the organic phase turned slightly purple. The organic phase was dried over MgSO and
2
2
2
4
filtered through Celite to give a light yellow solution and solvent was removed in vacuo to yield 6
as an white powder, 0.083 g (94 %).
1
2 2
H NMR (400 MHz, CD Cl ): δ 9.61 (d, 6-CH, J = 5.1 Hz, 1H), 8.03 (td, 4-CH, J = 8.0, 1.4 Hz,
1
H), 7.94 (d, 3-CH, J = 8.1 Hz, 1H), 7.63 (d, 3´-CH, J = 8.0 Hz, 1H), 7.52-7.40 (m, 5,o-CH, 3H),
.25 (t, m-CH, J = 7.3 Hz, 2H), 7.19 (m, p-CH, 1H), 7.14 (d, 4´-CH, J = 7.8 Hz, 1H), 6.55 (s, 6´-
7
CH, 1H), 2.18 (s, ArCH , 3H).
3
1
3
C NMR (101 MHz, CD
2 2
Cl ): δ 163.1, 150.8, 149.7, 143.3, 142. 8, 141.6, 140.9, 134.8, 133.6,
1
29.8, 128.9, 126.2, 125.3, 124.4, 120.3, 22.1.
81
+
79
+
MS (EI in CH
3
CN): m/z = 522.9 (0.6 % [M( Br)] ), 521.0 (0.7 % [M( Br)] ), 442.0 (0.1 % [M-
+
+
Br] ), 365.0 (4 % [M-Ph-Br] ), 245.1 (31 %), 244.1 (100 %).
7
9
MS-HR (CH
3
CN): 521.006245, calculated for C18
H15Au BrN 521.005346 (-1.7 ppm).
Anal. Calcd for C18
H15AuBrN: C, 41.40; H, 2.90; N, 2.68. Found: C, 41.91; H, 3.40; N, 2.63.
8

Compound 7: AuMe(OTf)(tpy)
1
3
In an NMR tube, AuBrMe(tpy) (4), an excess of AgOTf and CDCl was added. H NMR spectra
was acquired after approximately 24 hours. The only observed species was AuMe(OTf)(tpy) (7).
1
H NMR (400 MHz, CDCl
3
): δ 8.86 (d, 6-CH, J = 5.6 Hz, 1H), 8.03 (td, 4-CH, J = 8.1, 1.6 Hz, 1H),
.92 (d, 3-CH, J = 8.1 Hz, 1H), 7.61 (d, 3´-CH, J = 7.9 Hz, 1H), 7.57-7.50 (m, 5-CH, 1H), 7.22 (s,
´-CH, 1H), 7.19 (d, 4´-CH, J = 7.9 Hz, 1H), 2.42 (s, ArCH , 3H), 1.66 (s, AuCH , 3H).
7
6
3
3
9

1
3 2
H NMR spectrum of Au(OCOCF ) (tpy) (1)
1
0

1
3
3 2
C NMR spectrum of Au(OCOCF ) (tpy) (1)
1
1

1
9
3 2
F NMR spectrum of Au(OCOCF ) (tpy) (1)
1
2

1
3 2
H COSY NMR spectrum of Au(OCOCF ) (tpy) (1)
1
3

1
3 2
H NOESY NMR spectrum of Au(OCOCF ) (tpy) (1)
1
4

1
9
1
3 2
F- H HOESY NMR spectrum of Au(OCOCF ) (tpy) (1)
1
5

1
2
H NMR spectrum of AuMe (tpy) (2)
1
6

1
3
C NMR spectrum of AuMe (tpy) (2)
2
1
7

1
2
H COSY NMR spectrum of AuMe (tpy) (2)
1
8

1
2
H NOESY NMR spectrum of AuMe (tpy) (2)
1
9

1
2
H NMR spectrum of AuPh (tpy) (3)
2
0

1
3
2
C NMR spectrum of AuPh (tpy) (3)
2
1

1
2
H COSY NMR spectrum of AuPh (tpy) (3)
2
2

1
2
H NOESY NMR spectrum of AuPh (tpy) (3)
2
3

1
H NMR spectrum of AuBrMe(tpy) (4)
2
4

1
3
C NMR spectrum of AuBrMe(tpy) (4)
2
5

1
H COSY NMR spectrum of AuBrMe(tpy) (4)
2
6

1
H NOESY NMR spectrum of AuBrMe(tpy) (4)
2
7

1
2
H NMR spectrum of AuBrMe(tpy) (4) when attempted synthesis from AuCl (tpy)
2
8

1
H NMR spectrum of AuBrEt(tpy) (5)
2
9

1
3
C NMR spectrum of AuBrEt(tpy) (5)
3
0