230
A. Xia et al. / Journal of Organometallic Chemistry 682 (2003) 224ꢂ232
/
were obtained on a Haake-Buchler HBI digital melting
point apparatus and are uncorrected.
4.3. Synthesis of magnesium cyclopentadienyl amidinate
complexes
2
t
4
2
.3.1. Preparation of (CpMg(h - BuC(NAr) )) (Arꢃ
/
2
i
,6- Pr C H ) (3)
2
6
3
4
.2. Synthesis of amidines
A 100-ml Schlenk flask was charged with Cp Mg
2
(0.155 g, 1.00 mmol), MgMe (0.054 g, 1.0 mmol), and
Et O (30 ml). The solution was stirred at ambient
temperature for 1 h, and then 1 (0.840 g, 2.00 mmol)
was added. The resultant mixture was stirred for an
additional 18 h. Removal of the volatile components
2
2
t
4
2
.2.1. Preparation of BuC(NAr)(NHAr) (Arꢃ
/
i
,6- Pr C H ) (1)
2
6
3
A 1000-ml flask was charged with 1-chloro-1-(2,6-
diisopropylphenylimino)-2,2-di-methylpropane [23]
20.0 g, 71.6 mmol). Benzene (500 ml) and 2,6-diisopro-
pylaniline (12.7 g, 71.6 mmol) were added. The resultant
colorless solution was flushed with argon and then
refluxed for 24 h. The solution was cooled to 0 8C and
under reduced pressure afforded 3 as a white solid (0.860
ꢀ1
(
g, 87%): m.p. 280ꢂ282 8C; IR (Nujol, cm ) 1619 (w),
/
1
7
6
583 (w), 1178 (m), 1006 (m), 968 (m), 778 (s), 762 (m),
1
27 (m); H-NMR (benzene-d ): d 7.02 (m, 6H, C H ),
6
6
3
.34 (s, 5H, C H ), 3.23 (sept, 4H, (CH ) CH), 1.22 (d,
5
5
3 2
filtered through a coarse glass frit to afford 1×
white solid. Crude 1×HCl was dissolved in dichloro-
/
HCl as a
Jꢃ6.6 Hz, 24H, (CH ) CH), 0.78 (s, 9H, (CH ) C);
/
3 2 3 3
/
13
1
C{ H}-NMR (benzene-d , ppm): 178.96 (C- Bu),
t
6
methane (500 ml) and was then treated with 0.1 M
aqueous sodium carbonate (3.80 g, 35.8 mmol). The
dichloromethane layer was separated from the aqueous
layer, and removal of the dichloromethane afforded
crude 1 as a white solid. Recrystallization of the crude
material from EtOH afforded 1 as colorless crystals
1
42.94 (Cipso), 142.40 (Cortho), 124.49 (Cpara), 123.13
(
(
(
Cmeta), 106.70 (C H ), 43.21 (CH ) C), 30.03
5
CH(CH ) ),
3
CH(CH )(CH )?), 22.00 ((CH ) C). Anal. Calc. for
5
3 3
28.92
(CH(CH )CH )?),
25.45
2
3
3
3
3
3 3
C H MgN : C, 80.22; H, 9.50; N, 5.50. Found: C,
80.10; H, 9.61; N, 5.47%.
3
4
48
4
ꢀ
1
(
21.1 g, 70%): m.p. 138ꢂ
/
140 8C; IR (Nujol, cm ) 3416
(
m), 1656 (s), 1622 (m), 1607 (m), 1306 (m), 1230 (m),
2 t
.3.2. Preparation of (CpMg(THF)(h - BuC(NAr) ))
4
(
2
1
1
(
3
169 (m), 1127 (m), 1030 (m), 854 (m), 727 (s); H-NMR
benzene-d ): d 7.26ꢂ6.93 (m, 6H, Ph), 5.45 (s, 1H, NH),
.48 (septet, 2H, (CH ) CH), 3.29 (septet, 2H,
Arꢃ
In a procedure similar to the preparation of 3,
treatment of Cp Mg (0.077 g, 0.50 mmol) and MgMe
/
2,4,6-Me C H ) (4)
3 6 2
/
6
3
2
2
2
(
CH ) CH), 1.39 (d, Jꢃ6.4 Hz, 6H, (CH ) CH), 1.23
/
3
2
3 2
(
(
2
0.027 g, 0.50 mmol) with 2 (0.336 g, 1.00 mmol) in THF
20 ml) afforded 4 as a white solid (0.380 g, 76%): m.p.
1
3
(
d, Jꢃ6.4 Hz, 6H, (CH ) CH); C-NMR spectra
/
3 2
revealed extremely broad resonances, both at 23 and
0 8C in benzene-d , and are thus not reported. Anal.
ꢀ1
40 8C (dec); IR (Nujol, cm ) 1660 (m), 1621 (m), 1607
7
Calc. for C H N : C, 82.80; H, 10.54; N, 6.66. Found:
1
m), 1187 (m), 1009 (m), 854 (m), 764 (s), 727 (s); H-
6
(
NMR (benzene-d ): d 6.88 (s, 4H, C H ), 6.33 (s, 5H,
2
9
44
2
6
6
2
C, 83.02; H, 10.29; N, 6.66%.
C H ), 3.15 (m, 4H, THF), 2.36 (s, 12H, o-CH ), 2.24 (s,
5
5
3
6
H, p-CH ), 1.11 (m, 4H, THF), 0.94 (s, 9H, (CH ) C);
3 3 3
1
3
1
C{ H}-NMR (benzene-d , ppm): 175.81 (C- Bu),
t
6
t
4
Me C H ) (2)
.2.2. Preparation of BuC(NAr)(NHAr) (Arꢃ
/
2,4,6-
145.81 (Cipso), 131.74 (Cortho), 130.86 (Cpara), 128.99
(Cmeta), 105.47 (C H ), 68.62 (THF), 41.79 ((CH ) C),
3
6
2
5
5
3 3
In a fashion similar to the preparation of 1, treatment
of 1-chloro-2,2-dimethyl-1-(2,4,6-trimethylphenylimi-
no)propane [23] (32.0 g, 137.1 mmol) with 2,4,6-
trimethylaniline (18.6 g, 137.1 mmol) in benzene (600
29.39 (o-CH ), 24.67 (p-CH ), 20.90 (THF), 19.90
3 3
((CH ) C). Anal. Calc. for C H MgN O: C, 77.33;
3
3
32 44
2
H, 8.92; N, 5.64. Found: C, 76.91; H, 8.94; N, 5.67%.
ml) afforded 2×
/
HCl. Subsequent treatment with sodium
carbonate (7.27 g, 68.6 mmol), followed by recrystalliza-
4.3.3. Sublimation of 4
Compound 4 (0.250 g) was slowly heated to 160 8C in
a sublimation tube under reduced pressure (0.05 torr).
After 1 h under these conditions, the heating was
stopped and the tube was cooled to ambient tempera-
tion from EtOH, afforded 2 as white crystals (35.0 g,
ꢀ
1
7
6%): m.p. 159ꢂ
/
160 8C; IR (Nujol, cm ) 3396 (m),
3
332 (m), 1655 (m), 1613 (s), 1583 (m), 1321 (m), 1256
w), 1208 (w), 1169 (w), 1099 (w), 802 (w), 757 (m), 724
(
(
(
(
ture. The colorless crystals collected at the hot end were
1
Cp Mg (0.030 g, 77%) as determined by H-NMR (d
1
m); H-NMR (benzene-d ): d 6.84 (bs, 2H, Ph), 6.62
broad s, 2H, Ph), 4.94 (broad s, 1H, NH), 2.23, 2.08
6
2
1
3
5.96) and C-NMR (107.7 ppm) analyses, while the
1
broad s, 9H, CH ), 1.17 (broad s, 9H, C(CH ) ); C-
3
2 t
residue in the cold end was Mg(h - Bu(NAr) ) (Arꢃ
/
3
3 3
2
NMR spectra revealed extremely broad resonances,
both at 23 and 70 8C in benzene-d , and are thus not
2,4,6-Me C H ) (0.135 g, 77%, 5). Complex 5 can also
be prepared from MgBu (1.0 ml, 1.0 M in heptane) and
2
3
6
2
6
reported. Anal. Calc. for C H N : C, 82.09; H, 9.58;
2
2 (0.673 g, 2.00 mmol) in hexane in 95% yield: m.p. 277ꢂ
279 8C; IR (Nujol, cm ) 1654 (w), 1621 (m), 1605 (m),
/
6
38
2
ꢀ
1
N, 8.32. Found: C, 81.92; H, 9.68; N, 8.24%.