Organometallics
Article
reagents were purchased from commercial sources and used without
further purification. NMR spectra were recorded at 294 K, unless
otherwise stated, on either a 400 MHz Bruker Avance III
spectrometer, a 500 MHz Bruker Avance III spectrometer, or a 600
MHz Bruker Avance II spectrometer with a 5 mm QNP cryoprobe. All
1H NMR shifts are reported in ppm relative to the impurity of internal
solvent: specifically, benzene-d6 at δ 7.15 or toluene-d8 at δ 2.06.
Elemental analyses (C, H, N) were performed at Simon Fraser
University by Farzad Haftbaradaran by employing a Carlo Erba EA
1110 CHN elemental analyzer.
10.39 (s), 14.27 (v br s); (toluene-d8, 358 K) δ −8.67 (v br s), −7.99
(v br s), −3.35 (s), −2.20 (s), 0.00 (s), 2.95 (br s), 4.72 (s), 5.30 (s),
6.38 (br s), 9.01 (s), 9.12 (s), 9.22 (br s), 10,23 (s), 13.76 (v br s);
(toluene-d8, 298 K after heating) δ −9.58 (v br s), −4.22 (s), −2.85
(s), −0.42 (s), 5.33 (s), 6.07 (s), 7.72 (v br s), 9.24 (s), 9.45 (s), 10.75
(s), 10.98 (v br s), 15.46 (v br s).
iPr PhNCOCN]ThCl2·DME (5). [iPr PhNCOCN]H2n (0.521 g, 1.23
2
2
[
mmol) was dissolved in diethyl ether, and 2 equiv of BuLi (0.98 mL,
2.46 mmol) were added dropwise at 0 °C, resulting in a cloudy yellow
solution. The reaction was warmed to room temperature and
transferred via syringe to a cold (−78 °C) solution of ThCl4·2DME
(0.679 g, 1.23 mmol) in diethyl ether. Upon warming to room
temperature, the reaction became cloudy orange in color, and stirring
was continued at room temperature for 3 days. Excess solvent was
removed in vacuo to yield an orange solid. This solid was extracted
with toluene and filtered through a Celite-padded medium-porosity
glass frit. Excess toluene was removed in vacuo to yield an orange
[
tBuNON]ThCl5Li3·DME (1). [tBuNON]H2 (0.449 g, 1.63 mmol)
n
was dissolved in diethyl ether, and 2 equiv of BuLi (1.30 mL, 3.25
mmol) were added dropwise at 0 °C, resulting in a cloudy white
solution. The reaction was warmed to room temperature and
transferred via syringe to a cold (−78 °C) solution of ThCl4·2DME
(0.901 g, 1.63 mmol) in diethyl ether. Upon warming to room
temperature, the reaction was cloudy and beige in color, and stirring
was continued at room temperature for 3 days. Excess solvent was
removed in vacuo to yield a beige powder, which was extracted with
toluene and filtered through a Celite-padded medium-porosity glass
frit. Excess toluene was removed in vacuo to yield a beige powder of
powder of [iPr PhNCOCN]ThCl2·DME (5) (0.97 g, 97%). Crystals
2
suitable for X-ray diffraction were grown by slow evaporation of a
DME−toluene solution. Anal. Calcd for C32H52N2O31Cl2Th: C, 47.12;
H, 6.43; N, 3.43. Found: C, 47.37; H, 6.58; N, 3.31. H NMR (THF-
d8): δ 1.06 (d, 12H, CH(CH3)2), 1.32 (d, 12H, CH(CH3)2), 3.27 (s,
6H, O-CH3 DME), 3.43 (s, 4H, O-CH2 DME), 3.76 (t, 4H, N-CH2),
4.19 (m, 4H, CH(CH3)2), 4.43 (t, 4H, O-CH2), 6.90 (t, 2H, N-Ar-
para), 7.05 (d, 4H, N-Ar-meta). 13C{1H} NMR (THF-d8): δ 24.21
(CH(CH3)2), 24.50 (CH(CH3)2), 28.39 (CH(CH3)2), 35.21 (N-
CH2), 52.65 (N-CH2), 59.07 (O-CH3 DME), 68.76 (O-CH2), 72.91
(O-CH2 DME), 124.21 (Ar-CH), 124.75 (Ar-CH), 148.13 (Ar-C),
149.79 (Ar-C).
[
tBuNON]ThCl5Li3·DME (1) (0.80 g, 62%). Anal. Calcd for
C16H40N2O3Si2Cl5Li3Th: C, 24.18; H, 5.07; N, 3.52. Found: C,
24.37; H, 5.06; N, 3.17. 1H NMR (THF-d8): δ 0.89 (s, 6H, Si(CH3)2),
1.31 (s, 6H, Si(CH3)2), 1.33 (s, 18H, C(CH3)3), 3.27 (s, 6H, O-CH3),
3.43 (s, 4H, O-CH2). 13C{1H} NMR (THF-d8): δ 5.57 (Si(CH3)2),
27.11 (C(CH3)2), 34.57 (C(CH3), 35.15 (Si(CH3)2), 52.34 (O-CH3),
72.91 (O-CH2).
iPr PhNON]ThCl3Li·DME (3). [iPr PhNON]H2 n(0.131 g, 0.27 mmol)
2
2
[
was dissolved in diethyl ether, and 2 equiv of BuLi (0.22 mL, 0.54
mmol) was added dropwise at 0 °C, resulting in a clear bright-yellow
solution. The reaction was warmed to room temperature and
transferred via syringe to a cold (−78 °C) solution of ThCl4·2DME
(0.150 g, 0.27 mmol) in diethyl ether. Upon warming to room
temperature, the reaction was cloudy and bright-orange in color;
stirring was continued at room temperature for 18 h. Excess solvent
was removed in vacuo to yield an orange oil. This solid was extracted
with toluene and filtered through a Celite-padded medium-porosity
glass frit. Excess toluene was removed in vacuo to yield an orange−
[
tBuNON]Th(CH2SiMe3)2 (7). 1 (0.452 g, 0.73 mmol) was dissolved
in toluene, and 2 equiv of LiCH2SiMe3 (0.138 g, 1.46 mmol) were
added. Upon addition, the reaction turned bright-yellow in color.
Stirring was continued at room temperature for 18 h. The reaction was
filtered through a Celite-padded medium-porosity glass frit using
hexanes as the solvent, resulting in a clear yellow solution. Excess
hexanes was removed in vacuo to yield a yellow oil of [tBuNON]Th-
(CH2SiMe3)2 (7) (0.322 g, 83%). The 1H, 13C{1H} NMR spectra, and
elemental analysis are consistent with the previously published
synthesis of 7.65
yellow powder of [iPr PhNON]ThCl3Li·DME (3) (0.121 g, 48%). Anal.
2
2
2
[
iPr PhNCOCN]Th(CH2SiMe3)2 (9). [iPr PhNCOCN]ThCl2·DME
Calcd. for C32H56N2O3Si2Cl3LiTh: C, 41.85; H, 6.15; N, 3.05. Found:
(0.197 g, 0.241 mmol) was dissolved in toluene, and 2 equiv of
LiCH2SiMe3 (0.045 g, 0.482 mmol) were added. Upon addition, the
reaction turned bright-orange in color. Stirring was continued at room
temperature for 18 h. The reaction was filtered through a Celite-
padded medium-porosity glass frit using toluene as the solvent,
resulting in a clear-orange solution. Excess toluene was removed in
1
C, 41.82; H, 6.29; N, 2.97. H NMR (toluene-d8): δ 0.26 (s, 12H,
Si(CH3)2), 1.14 (d, 6H, CH(CH3)2), 1.22 (d, 6H, CH(CH3)2), 1.27
(d, 6H, CH(CH3)2), 1.45 (d, 6H, CH(CH3)2), 2.93 (br s, 4H, O-CH2
DME), 3.23 (br s, 6H, O-CH3 DME), 3.58 (sept, 1H, CH(CH3)2, 4.20
(sept, 1H, CH(CH3)2), 6.88−7.14 (m, 6H, Ar-H). 13C{1H} NMR
(toluene-d8): δ 1.77 (Si(CH3)2), 4.24 (SiCH3)2), 22.93 (CH(CH3)2),
24.29 (CH(CH3)2), 27.02 (CH(CH3)2), 27.42 (CH(CH3)2), 60.16
(O-CH3, DME), 70.95 (O-CH2, DME), 123.78 (Ar-para), 124.90 (Ar-
para), 128.62 (Ar-meta), 129.54 (Ar-meta), 132.64 (C-CH(CH3)2),
144.93 (N-Ar-C), 145.07 (N−Ar-C).
vacuo to yield a pale-orange powder of [iPr PhNCOCN]Th-
2
(CH2SiMe3)2 (9) (0.184 g, 92%). Crystals suitable for X-ray
diffraction were grown by slow evaporation of a hexanes solution.
Anal. Calcd for C36H64N2OSi2Th: C, 52.15; H, 7.78; N, 3.38. Found:
1
{[iPr PhNON]UCl2}2 (4). [iPr PhNON]H2 (0.316 g, 0.32 mmol) was
dissolved in diethyl ether, and 2 equiv of nBuLi (0.25 mL, 0.63 mmol)
was added dropwise at 0 °C, resulting in a clear bright-yellow solution.
The reaction was warmed to room temperature and transferred via
syringe to a cold (−78 °C) solution of UCl4 (0.120 g, 0.32 mmol) in
diethyl ether. Upon warming to room temperature, the reaction
became cloudy and orange−brown in color; stirring was continued at
room temperature for 18 h. Excess solvent was removed in vacuo to
yield a brown solid. This solid was extracted with toluene and filtered
through a Celite-padded medium-porosity glass frit. Excess toluene
was removed in vacuo to yield a brown−orange powder of
C, 51.95; H, 7.61; H, 2.99. H NMR (benzene-d6): δ −0.37 (s, 4H,
2
2
CH2SiMe3), 0.11 (s, 18H, CH2Si(CH3)3), 1.22 (d, 12H, CH(CH3)2),
1.49 (d, 12H, CH(CH3)2), 3.48 (t, 4H, O-CH2), 3.53 (t, 4H, N-CH2),
3.64 (m, 4H, CH(CH3)2), 6.85−7.02 (m, 6H, Ar-H). 13C{1H} NMR
(benzene-d6): δ 4.15 (CH2Si(CH3)3), 24.77 (CH(CH3)2), 27.35
(CH(CH3)2), 29.59 (CH(CH3)2), 58.38 (N-CH2), 76.36 (O-CH2),
90.73 (CH2SiMe3), 125.02 (Ar-ortho), 126.85 (N-Ar-para), 143.26 (N-
Ar-ispo), 137.58 (N-Ar-meta).
Typical Procedure for Hydroamination. Complex 6 (0.026 g,
0.0375 mmol, 10 mol %), 1,3,5-trimethoxybenzene (0.011 g, 0.0625
mmol), and 2,2-diphenyl-1-amino-4-pentene (0.089 g, 0.375 mmol)
were weighed into separate vials, dissolved, and combined in
approximately 0.5 g of deuterated benzene (or deuterated toluene
{[iPr PhNON]UCl2}2 (4) (0.235 g, 94%). Crystals suitable for X-ray
2
diffraction were grown by slow evaporation of a toluene solution. Anal.
Calcd for C63H100N4O2Si4Cl4U2: C, 45.16; H, 6.02; N, 3.34. Found: C,
45.51; H, 6.35; N, 3.53. 1H NMR (toluene-d8, 298 K) δ −9.61 (v br s),
−4.21 (s), −2.84 (s), −0.41 (s), 5.33 (s), 6.08 (s), 6.46 (v br s), 7.73
(v br s), 9.25 (s), 9.45 (s), 10.76, (s), 11.12 (v br s), 15.49 (v br s);
(toluene-d8, 338 K) δ −8.49 (vv br s), −3.62 (s), −2.40 (s), −0.14 (s),
4.91 (s), 5.54 (s), 6.68 (s), 6.81 (s), 9.08 (s), 9.22 (s), 9.79 (v br s),
1
for 1−4) in a J-Young sealable NMR tube. The H NMR spectrum
was obtained within 15 min to monitor conversion. By comparison of
the integration values for the proton signals of the 1,3,5-
trimethoxybenzene (δ 6.25 and 3.32 for aryl-H and −O(CH3)
protons, respectively) to the newly formed CH(CH3) signal (2.47
1
ppm) in the H NMR spectrum, the NMR the yield was obtained.
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dx.doi.org/10.1021/om300410h | Organometallics 2012, 31, 6732−6740