Mendeleev Commun., 2017, 27, 99–100
Me3SiON
C O
O
Me3SiONSiPhCl2
O
PhSiCl3
PhSiCl3
5
2
– Me3SiCl
– Me3SiOSiPhCl2
Me3SiONCOSiMe3
O=COSiMe3
Me3SiOCN
70 °C
– Me3SiCl
7
9
SiMe3
Me3SiN C O
6
5
O
O
Me3SiCl
2H
Scheme 2
Me3SiOCNH2
Me3SiOCNHSiMe3
10
However, it turned out that moving from Et3SiCl to PhSiCl3
hanges the direction of the reaction. The reaction was accompanied
O
c
Me3SiOCNHSiMe3
by the violent release of carbon dioxide and did not afford the
target 2. According to chromato-mass spectrometry data, another
organosilicon isocyanate, trimethylsilyl isocyanate 6 was un-
expectedly found in thermolysis products (see Scheme 2). In
addition, (Me3Si)2O, Me3SiOSiCl2Ph, Me3SiOSi(OSiMe3)ClPh,
and PhSi(OSiMe3)3 were also produced and characterized.
We can assume that after transsilylation of carbamate 5 with
HN
C
O
6
– (Me3Si)2O
– CO2
11
– Me3SiNH2
Scheme 4
References
1 V. P. Kozyukov, V. D. Sheludyakov and V. F. Mironov, Russ. Chem. Rev.,
1973, 42, 662 (Usp. Khim., 1973, 42, 1451).
2 E. V. Muzovskaya, V. P. Kozyukov and V. F. Mironov, Organosilil-
psevdogalogenidy i ikh ispol’zovanie v organicheskom sinteze (Organo-
silylpseudohalides and Their Use in Organic Synthesis), NIITEKHIM,
Moscow, 1985, p. 28 (in Russian).
PhSiCl3, partial desilylation of intermediate 7 occurs giving highly
reactive trimethylsilylnitrene 8 and carbon dioxide (Scheme 3).
Reasoning on this, we should expect the formation of oxygen along
with carbon dioxide. However, monitoring of gas released allowed
us to qualitatively identify the presence of carbon dioxide only.
3 V. F. Mironov and V. P. Kozyukov, Zh. Obshch. Khim., 1984, 54, 1217
(in Russian).
4 A. D. Kirilin, L. O. Belova, M. V. Pletneva, V. D. Sheludyakov and
A. A. Korlyukov, Russ. J. Gen. Chem., 2011, 81, 2252 (Zh. Obshch.
Khim., 2011, 81, 1799).
5 L. O. Belova, M.V. Pletneva, M. G. Shamina, N.A. Golub,A.A. Korlyukov
and A. D. Kirilin, Russ. J. Gen. Chem., 2014, 84, 1115 (Zh. Obshch.
Khim., 2014, 84, 932).
Me3SiONSiPhCl2
CO2
– O2
PhSiCl3
5
Me3SiN
6
– Me3SiCl
– Me3SiOSiPhCl2
– CO2
O=COSiMe3
8
7
Scheme 3
6 N. Sh. Pirkuliev, V. K. Brel, N. G. Akhmedov, N. S. Zefirov and P. J. Stang,
Mendeleev Commun., 2001, 171.
7 N. Sh. Pirkuliev, V. K. Brel, N. G. Akhmedov, N. S. Zefirov and P. J. Stang,
Mendeleev Commun., 2001, 172.
8 P. Salan´ski, Y. K. Ko and K.-I. Lee, Mendeleev Commun., 2006, 16, 48.
9 V. D. Sheludyakov, Reaktsii b-eliminirovaniya azotkremniisoderzha-
shchikh soedinenii so strukturnym fragmentom SiNCX (Reactions of
b-Elimination of Nitrogen and Silicon-containing Compounds with
SiNCX fragments), NIITEKHIM, Moscow, 1986, p. 67 (in Russian).
10 V. D. Sheludyakov, A. B. Dmitrieva, V. Yu. Tumanov, V. N. Bochkarev,
A. D. Kirilin and E. A. Chernyshev, Zh. Obshch. Khim., 1982, 52, 2142
(in Russian).
Apparently, after transsilylation of initial O-silylurethane 5
with PhSiCl3, an intermediate 7 is generated. Then the forma-
tion of (trimethylsiloxycarbonyl)nitrene 9 and its conversion
into N,O-bis(trimethylsilyl)carbamate 10 occur. The latter gives
isocyanic acid 11, whose silylation, finally, produces trimethyl-
silyl isocyanate 6 (Scheme 4).
In conclusion, we found a promising version for the produc-
tion of methyl isocyanate. Our findings in the study of trimethyl-
silyloxyl isocyanate synthesis can be of fundamental and practical
interest.
11 V. D. Sheludyakov, A. B. Dmitrieva, A. D. Kirilin and E. A. Chernyshev,
Zh. Obshch. Khim., 1983, 53, 706 (in Russian).
12 D. T. Hurd, J. Am. Chem. Soc., 1945, 67, 1545.
13 M. G. Voronkov and B. N. Dolgov, Zh. Obshch. Khim., 1954, 24, 1082
(in Russian).
The work was performed within the framework of the govern-
mental task no. 1984 ‘New polymeric materials based on organic
silicon compounds modified with carbon-containing fillers and
metal oxides’.
14 G. S. Forbes and H. H. Anderson, J. Am. Chem. Soc., 1948, 70, 1222.
‡
Thermolysis of trimethylsilyl N-trimethylsilyl-N-(trimethylsilyloxy)-
carbamate 5. Compound 5 (10 g, 0.034 mol) was added under stirring
to phenyltrichlorosilane (10.50 g, 0.05 mol), then additional amount of
phenyltrichlorosilane (10.50 g, 0.05 mol) was added. The reaction mass
was heated with the total refluxing head to 70°C, distilling 13.2 g of
volatile products. Final redistillation afforded 10.90 g (99%) of trimethyl-
chlorosilane, bp 56.8–57.0°C, nD20 = 1.3890 (lit., bp 57.7°C,12 nD20
=
= 1.389513) and 2.30 g (60%) of trimethylsilyl isocyanate 6, bp 90–91°C,
nD20 = 1.3948 (lit.,14 bp 91°C, nD20 = 1.3950). IR (KBr, n/cm–1): 2275
(N=C=O). MS, m/z: 115 [M–H]+ (calc. for C4H9NOSi, m/z: 115.2059).
Received: 10th March 2016; Com. 16/4869
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