B. Wrackmeyer et al. ■N-Silylaminotin Trichlorides
1013
moved in vacuo, and hexane
(
1
0
0
ml) was added to the
to 0 °C. Then SnCU (10,20 or 50 mmol) dissolved in pen-
residue. Insoluble material was filtered off, and hexane
tane ( 2
0
ml) was added dropwise to the stirred solutions.
was removed in vacuo. The stannylene 3d was obtained The solutions became colourless, and after warming to
as a dark-yellow, waxy solid (83%), and the plumby- room temperature a white precipitate (SnCl2) was filtered
lene 4d as a yellow solid (
temperature. 3d: ’H NMR (250.1 MHz; 25 °C; C
'H = 0.27 (s, 24H, MeSi), 0.80 (s, H, SiCH2); 13C of the compounds 1 and 2 in 1:1 to 4:1 ratio, depending
NMR (62.8 MHz; 25 °C, C D6): <513C = 4.0 (SiMe), 11.4 on the amount of SnCU used. These mixtures could not
8
8
%), which liquefies at room off. The pentane and the excess of SnCU were removed
6
D6):
in vacuo to leave yellowish waxy solids which consisted
6
8
6
(
2
=
<
SiCH2); 14N NMR (18.0 MHz; 25 °C; C
6
D6):
37 ± 2; 29Si NMR (49.7 MHz; 25 °C; C D6): <52 9Si
13.1 [< 10]; ll9Sn NMR (93.3 MHz; 25 °C; C
5U9Sn = 798.2. 4d: 'H NMR (250.1 MHz; 25 °C; C
5'H = 0.19 (s, 24H, MeSi), 0.82 (s,
NMR (62.8 MHz; 25 °C, C D6): <513C = 3.8 (SiMe), 14.1
SiCH2); I4N NMR (18.0 MHz; 25 °C; C D6): <5I4N -185
D6): 629Si = 11.4
D6): <52 07Pb =
6
14N -
be separated by distillation or sublimation.
6
6
6
D6):
D6):
Reactions of lithium amides Li(a) - Li(d) with SnCU in
1
:1 or smaller molar ratio
<
8
H, SiCH2); 13C
The lithium amides Li(a) - Li(d) (1 mmol) a suspen-
6
sions in pentane ( 1
0.26 - 1.3 g; 1 - 5 mmol) in pentane (10 ml) at 0 °C. Af-
ter filtration, all volatile material was removed in vacuo,
0
ml) were added to a solution of SnCU
(
±
6
(
2; 29Si NMR (49.7 MHz; 25 °C; C
6
[< 10]; 207Pb NMR (52.3 MHz; 25 °C; C
6
leaving again a mixture of the compounds
to 4:1 ratio.
1
and
2
in
1 : 2
4
962.
Preparation of the N-silylaminotin trichlorides 1 via the
plumbylenes 4
Reaction of the plumbylene 5 with SnCU
The plumbylenes 4a - 4d, respectively (5 mmol) were
dissolved in pentane (25 ml) and added dropwise to a solu-
A small amount (ca. 10 mg) of 5 was dissolved in CöD
in an NMR tube and cooled to 0 °C in an ice bath. Then
SnCU was injected through a syringe, and the mixture
6
tion of SnCU (
2
. 6 g;
1
0
mmol) in pentane
(
1
0
ml) at
0
°C.
The loss of the yellow colour of the plumbylene is accom-
panied by the precipitation of a colourless solid (PbCl2).
The mixtures were allowed to warm to room tempera-
ture, and kept stirring for another 30 min. After filtration
the solvent was removed in vacuo, the N-silylaminotin
was examined by NMR: the compounds
2 : 1 ) could be detected. After removing all volatile
material in vacuum, the residue was again dissolved in
. Compound was still present in the mixture, to-
gether with 7. After 5 h, all of was converted into 7 by
6
and 7 (ratio
«
C
6
Ö
6
6
6
trichlorides
waxy solids in 83-85% yield, la: m. p. 78 °C; 'H NMR
250.1 MHz; 25 °C; C D6): 6 1H = 0.19 (s, 9H, MeSi).
lb: m. p. 65 °C; 'H NMR (250.1 MHz; 25 °C; C D6):
SlH = 0.24 (s, 9H, MeSi); 1.21 (s, 9H, MeC). lc: m.
p. 59 °C; 'H NMR (250.1 MHz; 25 °C; C D6): <5'H =
.19 (s, 9H, MeSi); 1.27 (m, broad, 2H, BCH), 1.41-1.80
m, 12H, CH CB/CH CCB). ld: m. p. 62 °C; 'H NMR
250.1 MHz; 25 °C; C D6): <5*H = 0.18 (s, 12H, MeSi;
.80 (s,4H, CH2).
1
were left as colourless, moisture-sensitive,
elimination of SnCU which could be detected by ll9Sn
NMR and was also found as one of the volatile materials
present in this solution.
(
6
6
Preparation of the trimethyltin amides
elimination
8
via salt
6
0
(
(
2
2
The respective lithium amide Li(a) - Li(d) (1 mmol)
was suspended in hexane (15 ml), and the suspension was
cooled to -78 °C. Then MejSnCl (1.0 mmol; 0.20 g) was
added in several portions under stirring. The mixture was
allowed to warm to room temperature and insoluble mate-
rial was filtered off. After removing the solvent in vacuo,
6
0
Reaction of an excess ofplumbylenes 4 with SnCl4
Tin tetrachloride (0.26 to 1.3 g; 1to 5 mmol) in pentane
(
-
20 ml) were added to a solution of the plumbylenes 4a
the compounds
5% yield) which partially solidified to waxy solids. 8a:
H NMR (250.1 MHz; 25 °C; C D6): <5‘H = 0.17 (s, 18H,
a mixture of the compounds 1 and 2 in 1:1 to 4:1 ratio MeSi), 0.24 (s 9H, MeSn). 8b: 'H NMR (250.1 MHz;
8
were obtained as colourless oils (
8
8
-
4d, respectively (5 mmol) in pentane (10 ml) at 0 °C.
9
'
After filtration the pentane was removed in vacuo and
6
remeined (depending on the amount of SnCU), which
could not be separated, neither by crystallisaton nor by
distillation or sublimation (decomposition).
2
5 °C; C
MeSn), 1.24 (s, 9H, MeC). 8c: 'H NMR (250.1 MHz;
5 °C; C D6): *H = 0.16 ( s , 9H, MeSi), 0.25 (s, 9H,
MeSn), 1.30 (m, broad, 2H, BCH), 1.35-1.78 (m, 12H,
CH CB/CH CCB). 8d: 'H NMR (250.1 MHz; 25 °C;
D6): <5‘H = 0.13, (12H, MeSi), 0.19 (s, 9H, MeSn),
Si).
6
D6): <5‘H = 0.12 (s, 9H, MeSi), 0.29 (s, 9H,
2
6
6
Reactions of stannylenes 3 with SnCU in excess
2
2
The stannylenes 3a - 3d, respectively (5 mmol), were
C
6
dissolved in pentane ( 1
0
ml) and the solution was cooled 0.82 (s, 4H, CH
2
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