700 Organometallics, Vol. 26, No. 3, 2007
Cruz et al.
(CHMe2). Anal. Calcd for C55H82N2O5K2: C, 71.07; H, 8.89; N,
3.01. Found: C, 71.16; H, 8.86; N, 3.10.
temperature and filtered, and the solvent was removed in Vacuo.
Hexanes (30 mL) were added, followed by sonication and filtration
1
to give 6 as a white solid (0.378 g, 0.36 mmol) in 59% yield. H
Na2[XA2] (3). NaH (0.100 g, 4.17 mmol) and H2[XA2] (0.700
g, 1.04 mmol) were refluxed in toluene (60 mL) for 2-12 days.66
The solution was then filtered to remove excess NaH, solvent was
removed in Vacuo, and hexamethyldisiloxane (30 mL) was added.
Sonication and filtration gave 0.555 g (0.866 mmol, 84%) of 3 as
NMR (C6D6, 600 MHz): δ 7.31 (m, 4H, J 7.5 Hz, Ar-H), 7.25 (m,
2H, J 7.5 Hz, Ar-H), 6.85 (d, 2H, J 1.8 Hz, CH3), 5.89 (d, 2H, J
1.8 Hz, CH1), 4.06 (sept, 4H, J 6.8 Hz, CHMe2), 3.04 (s, 4H,
OCH2), 2.25 (s, 6H, OCH3), 1.70 (s, 6H, CMe2), 1.47 (d, 12H, J
6.7 Hz, CHMe2), 1.25 (s, 18H, CMe3), 1.09 (d, 12H, J 6.9 Hz,
CHMe2). 13C{1H} NMR (C6D6, 150 MHz): δ 149.4 (Ar-Cortho),
147.1, 145.9, 141.3 (Xanth-Q), 142.0 (Ar-Cipso), 127.3 (Ar-CHpara),
125.4 (Ar-CHmeta), 111.7 (CH1), 111.4 (CH3), 71.0 (OCH2), 61.3
(OMe), 34.9 (CMe3), 34.1 (CMe2), 33.8 (CMe2), 31.7 (CMe3), 28.1
(CHMe2), 27.2, 24.8 (CHMe2). Anal. Calcd for C51H72Cl2N2O3Th:
C, 57.57; H, 6.82; N, 2.63. Found: C, 57.76; H, 6.89; N, 2.49.
1
a white solid. H NMR (C6D6, 600 MHz): δ 7.28 (d, 4H, J 7.65
Hz, Ar-H), 7.19 (t, 2H, J 7.6 Hz, Ar-H), 6.67 (d, 2H, J 2.0 Hz,
CH3), 6.34 (d, 2H, J 2.0 Hz, CH1), 2.98 (sept, 4H, J 6.9 Hz,
CHMe2), 1.81 (s, 6H, CMe2), 1.35 (s, 18H, CMe3), 1.29 (d, 12H,
J 6.8 Hz, CHMe2), 0.99 (d, 12H, J 7.1 Hz, CHMe2). 13C{1H} NMR
(C6D6, 150 MHz): δ 151.8, 148.8, 146.2, 133.0 (Xanth-Q), 137.4
(Ar-Cipso), 128.6 (Ar-Cortho), 125.0 (Ar-CHmeta), 121.2 (Ar-CHpara),
109.4 (CH3), 101.2 (CH1), 35.8 (CMe2), 34.4 (CMe3), 31.4 (CMe3),
28.3 (CMe2), 27.7 (CHMe2), 24.0, 23.4 (CHMe2). Anal. Calcd for
C47H62N2Na2O: C, 78.73; H, 8.72; N, 3.91. Found: C, 79.09; H,
8.65; N, 3.96.
[(BDPP)Th(CH2SiMe3)2] (7): Method A. ThCl4(dme)2 (0.750
g, 1.35 mmol) and LiCH2SiMe3 (0.510 g, 5.41 mmol) in toluene
(60 mL) were stirred for 1 h at -78 °C followed by 1 h at 0 °C.
The cloudy, colorless solution was then recooled to -78 °C, and a
solution of 2,6-bis(2,6-diisopropylanilinomethyl)pyridine (0.620 g,
1.35 mmol) in toluene (10 mL) was added dropwise. The solution
was allowed to warm to room temperature over ca. 2 h, stirred for
an additional 12 h, and then filtered to remove lithium salts. Solvent
was removed in Vacuo and hexamethyldisiloxane (30 mL) was
added, followed by sonication and filtration to afford 7 as an off-
white solid (0.949 g, 1.10 mmol) in 82% yield. Method B.
[(BDPP)ThCl2(dme)] (0.150 g, 0.18 mmol) and LiCH2SiMe3 (0.033
g, 0.35 mmol) in toluene (15 mL) were stirred for 30 min at room
temperature. The solution was filtered, and solvent was removed
in Vacuo. Hexamethyldisiloxane (10 mL) was added, followed by
sonication and filtration to afford 7 as an off-white solid (0.106 g,
Li2[BDPP] (4). nBuLi (2.0 M) in cyclohexane (2.20 mL, 4.37
mmol) was added dropwise to 2,6-bis(2,6-diisopropylanilinometh-
yl)pyridine (1.00 g, 2.19 mmol) in hexanes (30 mL) at -78 °C.
After stirring at -78 °C for 5 min the solution was warmed to
-45 °C for 5 min to give a yellow-brown solution with large
amounts of yellow precipitate. The mixture was then recooled to
-78 °C and filtered quickly on a precooled frit to provide 4 as a
1
yellow solid (0.898 g, 1.91 mmol) in 87% yield. H NMR (d8-
THF,30 -30 °C, 500 MHz): δ 7.58 (t, 1H, J 7.3 Hz, py-CH), 7.44
(d, 2H, J 7.3 Hz, py-CH), 6.71 (d, 4H, J 7.3 Hz, Ar-H), 6.23 (t,
2H, J 7.3 Hz, Ar-H), 4.78 (s, 4H, NCH2), 3.73 (sept, J 6.9 Hz,
CHMe2), 1.11 (d, 24H, J 6.7 Hz, CHMe2). 13C{1H} NMR (d8-THF,
-30 °C, 125 MHz): δ 166.4 (Py-Cortho), 160.1 (Ar-Cipso), 138.5
(Ar-Cortho), 133.0 (Py-CHpara), 120.8 (Ar-CHmeta), 115.9 (Py-CHmeta),
110.2 (Ar-CHpara), 62.4 (NCH2), 25.5 (CHMe2), 21.0 (CHMe2).
Anal. Calcd for C31H41N3Li2: C, 79.29; H, 8.80; N 8.95. Found:
C, 79.15; H, 9.21; N, 8.49.
1
0.12 mmol) in 68% yield. H NMR (C6D6): δ 7.24 (m, 6H, Ar-
H), 6.90 (t, 1H, J 7.7 Hz, py-CH), 6.49 (d, 2H, J 7.7 Hz, py-CH),
5.24 (s, 4H, NCH2), 3.75 (sept, 4H, J 6.8 Hz, CHMe2), 1.52 (d,
12H, J 6.8 Hz, CHMe2), 1.26 (d, 12H, J 6.8 Hz, CHMe2), -0.02
(s, 18H, SiMe3), -0.32 (s, 4H, ThCH2). 13C{1H} NMR (C6D6, 150
MHz): δ 164.8 (Py-Cortho), 148.1 (Ar-Cipso), 141.9 (Ar-Cortho), 138.4
(Py-CHpara), 126.8 (Ar-CHmeta), 125.0 (Ar-CHpara), 117.8 (Py-
CHmeta), 89.9 (ThCH2), 68.7 (NCH2), 28.7 (CHMe2), 27.3, 24.9
(CHMe2), 3.8 (SiMe3). Anal. Calcd for C39H63N3Si2Th: C, 54.33;
H, 7.37; N, 4.87. Found: C, 54.10; H, 7.35; N, 4.69.
[(BDPP)ThCl2(dme)] (5): Method A. ThCl4(dme)2 (0.600 g,
1.08 mmol) and LiCH2SiMe3 (0.204 g, 2.17 mmol) in toluene (60
mL) were stirred for 1 h at -78 °C followed by 1 h at 0 °C. A
solution of 2,6-bis(2,6-diisopropylanilinomethyl)pyridine (0.620 g,
1.35 mmol) in toluene (10 mL) was then added dropwise. The
solution was allowed to warm to room temperature over ca. 2 h,
stirred for an additional 12 h, and then filtered to remove lithium
salts. Solvent was removed in Vacuo, and hexanes (30 mL) were
added, followed by sonication and filtration to give 5 as a white
solid (0.781 g, 0.92 mmol) in 85% yield. Method B. ThCl4(dme)2
(0.140 g, 0.25 mmol) in benzene (10 mL) was placed in an ice-
water bath (the majority of the solution does not freeze, despite
the 6 °C freezing point of benzene). A solution of Li2[BDPP] (0.119
g, 0.25 mmol) in benzene30 (5 mL) was added dropwise (over 1-2
min). The solution was stirred for 1 h, followed by filtration and
removal of solvent in Vacuo. Hexanes (10 mL) were added,
followed by sonication and filtration to give 5 as a white solid (0.109
g, 0.13 mmol) in 51% yield. 1H NMR (C6D5Br, 600 MHz): δ 7.24
(t, 1H, J 7.6 Hz, py-CH), 7.17 (m, 6H, Ar-H), 6.85 (d, 2H, J 7.6
Hz, py-CH), 5.27 (s, 4H, NCH2), 4.19 (sept, J 6.7 Hz, CHMe2),
3.42 (s, 2H, OCH2), 2.38 (s, 3H, OCH3), 1.42, 1.15 (d, 24H, J 6.7
Hz, CHMe2). 13C{1H} NMR (C6D6, 150 MHz): δ 165.0 (Py-Cortho),
148.1 (Ar-Cipso), 147.6 (Ar-Cortho), 137.4 (Py-CHpara), 125.3 (Ar-
CHmeta), 116.8 (Py-CHmeta), 124.2 (Ar-CHpara), 70.6 (NCH2), 27.8
(CHMe2), 27.0, 24.3 (CHMe2). Anal. Calcd for C35H51Cl2N3O2Th:
C, 49.53; H, 6.06; N 4.95. Found: C, 49.85; H, 6.35; N, 4.37.
[(XA2)ThCl2(dme)] (6). ThCl4(dme)2 (0.416 g, 0.75 mmol) and
K2(dme)2[XA2] (0.700 g, 0.75 mmol) in toluene (60 mL) were
stirred for 16 h at 100 °C. The solution was cooled to room
[(XA2)Th(CH2SiMe3)2] (8): Method A. Complex 8 was
prepared in a similar fashion to 7 (method A) using 0.750 g (1.35
mmol) of ThCl4(dme)2, 0.510 g (5.41 mmol) of LiCH2SiMe3, and
0.909 g (1.35 mmol) of H2[XA2]. However, the crude filtered
product was sonicated in hexanes (20 mL) before filtration to give
0.710 g of 8 as a white solid (0.711 g, 0.66 mmol) in 49% yield.
Method B. Complex 8 was prepared in a similar fashion to 7
(method B) using [(XA2)ThCl2(dme)] (0.250 g, 0.25 mmol) and
LiCH2SiMe3 (0.048 g, 0.51 mmol). However, the crude filtered
product was sonicated in hexanes (10 mL) before filtration to afford
1
8 as a white solid (0.175 g, 0.16 mmol) in 65% yield. H NMR
(d8-toluene, 600 MHz): δ 7.26 (m, 6H, Ar-H), 6.77 (d, 2H, J 1.5
Hz, CH3), 6.00 (d, 2H, J 1.5 Hz, CH1), 3.54 (sept, 4H, J 7.0 Hz,
CHMe2), 1.66 (s, 6H, CMe2), 1.40 (d, 12H, J 7.0 Hz, CHMe2),
1.16 (d, 12H, J 7.0 Hz, CHMe2), 0.03 (s, 18H, SiMe3), -0.17 (s,
4H, ThCH2). 13C{1H} NMR (d8-toluene, 150 MHz): δ 146.2 (Ar-
Cortho), 148.5 (Xanth-Q), 142.6 (Ar-Cipso), 130.3 (Ar-CHpara), 129.7
(Ar-CHmeta), 110.7 (CH1), 110.9 (CH3), 35.6 (CMe3), 35.5 (CMe2),
31.4 (CMe2), 32.1 (CMe3), 29.5 (CHMe2), 26.8, 25.5 (CHMe2), 3.4
(SiMe3). Note: ThCH2 was not observed at room temperature but
was observed at +50 or -80 °C (see main text). Anal. Calcd for
C55H84N2OSi2Th: C, 61.31 H, 7.86; N, 2.60. Found: C, 61.41; H,
8.06; N, 2.37.
[Th(BDPP)2] (9): Method A. [(BDPP)Th(CH2SiMe3)2] (7)
(0.200 g, 0.23 mmol) and 2,6-bis(2,6-diisopropylanilinomethyl)-
pyridine (0.106 g, 0.23 mmol) in benzene (15 mL) were heated at
100 °C for 24 h in a sealed flask. Upon cooling, the reaction mixture
(66) The reaction time was not reproducible. Typically, no reaction is
observed for days, but once the reaction begins, it takes less than 24 h to
reach completion.