Direct displacement of chlorine or iodine in reactions of (Me3Si)3CSiRR′X with metal salts

Article abstract of DOI:10.1016/S0022-328X(99)00709-3

Direct nucleophilic displacement of halide X (X=Cl or I) takes place when the compounds (Me₃Si)₃CSiRR′X with R=Me, R′=(C₆H₄Me-p), (C₆H₄OMe-p), CH₂=CH R=Bu, R′=Cl, or R=Ph, R′=Ph

Full text of DOI:10.1016/S0022-328X(99)00709-3

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 598 (2000) 222–227
Direct displacement of chlorine or iodine in reactions of
(Me3Si)3CSiRR%X with metal salts
Kazem D. Safa *, Mohammad G. Asadi, Abdolreza Abri, Ali Mohammadpour,
Hadi Kiae
Faculty of Chemistry, Uni6ersity of Tabriz, Tabriz, Iran
Received 1 December 1998; received in revised form 7 November 1999
Abstract
Direct nucleophilic displacement of halide X (X=Cl or I) takes place when the compounds (Me3Si)3CSiRR%X with R=Me,
R%=(C6H4Me-p), (C6H4OMe-p), CH2ꢀCH R=Bu, R%=Cl, or R=Ph, R%=Ph are treated with solutions of KOCN, KSCN,
KCN, or NaN3 in CH3CN or MeOH, and H2O in DMSO, or CH3CN. © 2000 Elsevier Science S.A. All rights reserved.
Keywords: Silicon; Steric Hindrance; Trisyl
The presence of even one hydride ligand reduces the
steric hindrance considerably and we have seen that for
such compounds nucleophilic substitution takes place
fairly readily.
In this work we synthesised new compounds with
different groups and did some nucleophilic reactions on
them with linear nucleophiles, namely N−3 , SCN−,
OCN− and CN−, to examine the ease of reactions on
Si bearing the bulky trisyl group.
1. Introduction
The effect of severe steric hindrance on direct nucleo-
philic attack at functional silicon centres bearing the
bulky trisyl group (denoted here by Tsi) or a related
group has allowed the observation of previously inac-
cessible mechanisms of reactions [1]. For example, un-
usual rearrangement and migration in TsiSiR2X species
take place through bridged silicocationic intermediates.
When the steric hindrance at the functional silicon
centres is reduced, or linear nucleophiles like N−3 ,
SCN−, OCN− and CN− are used, direct biomolecular
displacement takes place. Earlier work had indicated
that nucleophilic substitution, while relatively easy for
TsiSiMe2X, was very slow for TsiSiPh2I [2–5]. But we
have now shown that under suitable conditions such
substitution reactions provide a satisfactory route to
TsiSiPh2X and some related species.
We have also shown that with less hindered systems
the chlorides can be satisfactorily used instead of
iodides. For example, TsiSiMe(CHꢀCH2)Cl and TsiSi-
BuCl2 undergo direct nucleophilic reactions to give the
corresponding products. The chlorides (C6H4OMe-p)-
SiMeHCl and (C6H4Me-p)SiMeHCl react with TsiLi to
give trisyl derivatives containing a hydride substituent.
2. Results and discussion
In our earlier work we have shown that the synthesis
of TsiSiAn2I by the reaction of TsiSiAn2H with ICl was
unsuccessful [1]. An attempt to make TsiSi (C6H4Me-
p)2F by reaction of TsiLi with (C6H4Me-p)2SiF2 was
also unsuccessful. For that reason in order to reduce
steric hinderance we have chosen methylanisyl and
methyltolyl derivatives to prepare TsiSi(C6H4OMe-
p)MeI and TsiSi(C6H4Me-p)MeI, respectively and stud-
ied the reaction of the iodides with electrophiles,
nucleophiles and alkoxides. When steric hinderance of
the functional silicon centre is reduced or linear nucle-
ophiles such as NCS−, NCO−, CN− are used, such
bimolecular displacement reactions take place and no
rearrangement is observed.
* Corresponding author.
E-mail address: g-asadi@ank.tabriz.ac.ir (K.D. Safa)
0022-328X/00/$ - see front matter © 2000 Elsevier Science S.A. All rights reserved.
PII: S0022-328X(99)00709-3

K.D. Safa et al. / Journal of Organometallic Chemistry 598 (2000) 222–227
223
When Me is substituted with a bulky anisyl group in
3.2. Spectra
TsiSi(C6H4OMe-p)2H the iodide derivative TsiSi-
(C6H4OMe-p)MeI was successfully prepared by the
reaction of TsiSi(C6H4OMe-p)MeH with ICl. So we
think that by reducing steric hinderance around the Si
centre, the cleavage of the SiꢁAryl bond was not
favoured.
1
The H-NMR spectra were recorded using an FT-
NMR Bruker (100 MHz) and FT-NMR 90 MHz spec-
trometer with solutions in CDCl3. The IR spectra were
recorded on an FTIR, DR.8001-Shimadzu spectrome-
ter. Mass spectra were obtained with a Finnigan-Mat
model 8400, 70 eV. Melting points were determined
with a 9100 Electrothermal apparatus.
2.1. Preparation of TsiSiRR%X
3.3. Preparation of trisyldiphenylisocyanato silane
TsiSiPh2NCO
These compounds were obtained by reaction of TsiLi
with (a) n-BuSiCl3; (b) (C6H4OMe-p)SiMeHCl; (c)
(C6H4Me-p)SiMeHCl; (d) CH2ꢀCHSiMeCl2; (e)
Ph2SiF2.
A mixture of TsiSiPh2I (0.5 g, 0.93 mmol), KOCN (2
g, 24.7 mmol) and crown ether (0.2 g, 0.55 mmol) in
CH3CN (50 cm3) was refluxed for 16 days. The mixture
was treated with methanol (20 cm3), n-hexane (40 cm3),
and a little NaCl aqueous solution, washed several
times with water, and the organic layer was separated,
dried (MgSO4), evaporated and the residue recrys-
tallised from EtOH (78%); m.p. 178–179°C FTIR
(KBr, cm−1) w(SiꢁNCO)2278.1, (CꢁSi) 1245.1H-NMR
(CDCl3): 0.12 (s, 27H, Tsi), and 7.13–7.50 ppm (m,
10H, ArylꢁH). m/z (EI): 440 (20%, [MꢁMe]+), 413
(38%, [MꢁNCO]+), 335 (100%, [MꢁPhꢁSiMe]+), 247
(60%, [Mꢁ2PhꢁCH2SiC]+), 197 (38%, [MꢁTsiꢁSi]+).
(Found: C, 60.2; H, 8.1; N, 3.02, C23H37Si4NO Calc.: C,
60.66; H, 8.13; N, 3.07%).
2.2. Reactions of TsiSiRR%X (R=Me, n-Bu, Ph, and
R%=p-C6H4OMe, p-C6H4Me, Cl, CH2ꢀCH)
(i) The butyl compound TsiSiBuCl2 was only reacted
with KSCN and KN3 in CH3CN. The difluoride deriva-
tive of this compound was prepared and unlike other
derivatives of trisyl compounds is a liquid.
(ii) The vinyl compound TsiSiMe(CHꢀCH2)Cl was
found to react with KSCN, NaN3, KCN, and KOCN
in CH3CN to give TsiSiMe(CHꢀCH2)Y (Y=NCS,
NCO, N3, CN).
(iii) The methyltolyl and methylanisyl compounds
TsiSi(C6H4Me-p)MeI, TsiSi(C6H4OMe-p)MeI were re-
acted with KSCN in CH3CN, and H2O in DMSO,
CH3CN [6–9]. The hydrides TsiSi(C6H4Me-p)MeH,
TsiSi(C6H4OMe-p)MeH were subsequently made by
the treatment of TsiLi with (C6H4Me-p)MeSiHCl and
(C6H4OMe-p)MeSiHCl, respectively.
(iv) The diphenyl compound TsiSiPh2I was found to
react with KSCN, KOCN in CH3CN containing crown
ether and NaN3 in MeOH containing crown ether. The
reaction of TsiSiPh2I with KSCN in CH3CN was previ-
ously reported requiring 30 days [10], but we found that
it to be complete in 3 days in a mixture of CH3CN and
18-crown-6. We also found that TsiSiPh2I did not react
with KCN in MeOH. The reaction of the
TsiSi(C6H4ꢁMe-p)MeI, TsiSi(C6H4ꢁOMe-p)MeI with
H2O, DMSO, CH3N give the silanol derivatives,
TsiSi(C6H4ꢁMe-p)MeOH, TsiSi(C6H4ꢁOMe-p)MeOH.
3.4. Preparation of trisylazidodiphenylsilane TsiSiPh2N3
A mixture of TsiSiPh2I (0.5 g, 0.93 mmol), NaN3 (2
g, 30.7 mmol) and crown ether (0.2 g, 0.55 mmol) in
MeOH (50 cm3) was refluxed for 14 days. The mixture
was treated with methanol (20cm3), n-hexane (40 cm3),
and a little NaCl aqueous solution, washed several
times with water, and the organic layer was separated,
dried (MgSO4), evaporated and the residue recrystal-
lized from EtOH. (83%); m.p. 137.5–138.5°C. FTIR
(KBr, cm−1), w(SiꢁN3) 2143.3. 1H-NMR (CDCl3):
0.112 (s, 27H, Tsi), and 7.12–7.65 ppm (m, 10 H,
ArylꢁH). m/z (EI): 440 (8%, [MꢁMe]+), 397 (2%,
[MꢁN3]+), 335 (41%, [MꢁPhꢁSiMe]+), 247 (25%,
[Mꢁ2PhꢁCH2SiC]+), 197 (12%, [MꢁTsiꢁSi]+), 175
(15%,[Mꢁ2(SiMe3)ꢁPhMeꢁ3N]+). (Found: C, 58.2; H,
8.4; N, 8.7. C22H37Si4N3 Calc.: C, 58.02; H, 8.13; N,
9.2%).
3. Experimental
3.5. Preparation of trisyldiphenylisothiocyanatosilane
TsiSiPh2NCS
3.1. Sol6ents and reagents
A mixture of TsiSiPh2I (0.5 g, 0.93 mmol), KSCN
(0.9 g, 9.26 mmol) and crown ether (0.02 g, 0.05 mmol)
in CH3CN (50 cm3) was refluxed for 3 days. The
mixture was treated with methanol (20 cm3), n-hexane
(40 cm3), and a little NaCl, washed several times with
Reactions involving lithium metal, organolithium or
organomagnesum reagents and LiAlH4 were carried out
under dry argon. Solvents were dried by standard
methods.

224
K.D. Safa et al. / Journal of Organometallic Chemistry 598 (2000) 222–227
water, the organic layer was separated, dried (MgSO4),
evaporated and the residue recrystallised from EtOH.
(87%); m.p. 139–141°C. FTIR (KBr, cm−1), (SiꢁNCS)
2073.8. 1H-NMR (CDCl3): 0.99 (s, 27H, Tsi), and
7.12–7.62 ppm (m, 10H, ArylꢁH). m/z (EI): 456 (48%,
[MꢁMe]+), 397 (40%, [MꢁMe3SiH]+), 378 (72%,
[MꢁPhꢁCH4]+), 340 (15%, [MꢁMe3SiꢁNCS]+), 325
(15%, [Mꢁ(Me3Si)2]+), 145 (11%, [MꢁSiMe3ꢁCSiPh2-
NCS]+), 135 (85%, [SiMe2Ph]+,), 135 (85%,
[MꢁTsiꢁSiPh]+). (Found: C, 58.3; H, 7.9; N, 3.2.
C23H37Si4SN Calc.: C, 58.5; H, 7.8; N, 3.0%).
refluxed for 48 h. The mixture was treated with diethyl
ether and water, the organic layer separated, dried
(MgSO4), evaporated and the residue recrystallised
from EtOH (79%), m.p. 275°C. FTIR (KBr, cm−1),
1
(SiꢁN3) 2139.4, H-NMR (CDCl3): 0.27 (s, 27 H, Tsi),
0.57 (s, 3H, SiꢁMe) and 5.7–6.5 ppm (m, 3H,
CHꢀCH2). m/z (EI): 328 (12%, [MꢁMe]+), 284 (8%,
[MꢁN3ꢁCH4]+), 228 (14%, [MꢁMe3SiN3]+), 200 (18%,
[MꢁMe3SiN3ꢁ(CHꢀCH2)]+).
3.9. Preparation of trisylcyanidomethyl6inylsilane
TsiSi(CH3)(CHꢀCH2)CN
3.6. Preparation of trisylmethyl6inylchlorosilane
TsiSi(CH3)(CHꢀCH2)Cl
A mixture of TsiSi(CH3)(CHꢀCH2)Cl (1 g, 3 mmol),
KCN (2 g, 43.4 mmol) in CH3CN (150 cm3) was
refluxed for 38 h. The mixture was treated with diethyl
ether and water, the organic layer separated, dried
(MgSO4), evaporated, and purified by column chro-
matography (Silicagel, n-hexane as eluant). (87%); m.p.
Dichloromethylvinylsilane
Cl2Si(CH3)(CHꢀCH2)
(7.05 g, 50 mmol) was added dropwise with stirring to
a solution of TsiLi (50 mmol) in THF (50 cm3) that had
been made by reaction of TsiH (11.5 g, 50 mmol) with
MeLi (0.84 g, 120 mmol). The mixture was refluxed for
45 min. Then aqueous NH4Cl was added and the
organic compound was extracted with Et2O. The ex-
tract was dried (MgSO4), filtered and evaporated, and
the residue recrystallized from EtOH, then purified by
column chromatography (silica gel, n-hexane as eluant)
to give TsiSi(CH3)(CHꢀCH2)Cl (55%), m.p. 340°C
FTIR (KBr, cm−1), (ꢀCꢁH) 3061.5, (CꢁH aliphatic)
1
328°C. FTIR (KBr, cm−1), (SiꢁCN) 2185.7, H-NMR
(CDCl3): 0.33 (s, 27H, Tsi), 0.62 (s, 3H, SiꢁMe) and
5.6–6.4 ppm (m, 3H, vinyl). m/z (EI): 312 (38%,
[MꢁMe]+), 285 (28%, [Mꢁ(CHꢀCH2)ꢁMe]+), 224 (24%,
[MꢁMe3Siꢁ2Me]+), 213 (99%, [MꢁMe3SiꢁMeꢁCN]+),
201 (46%, [MꢁTsiꢁ2Me]+), 155 (33%, [Mꢁ(Me3Si)2ꢁ
CN]+).
1
2962.2, 2987.2, (CꢀC) 1592.5. H-NMR (CDCl3): 0.31
3.10. Preparation of trisylisocyanatomethyl6inylsilane
TsiSi(CH3)(CHꢀCH2)NCO
(s, 27H, Tsi), 0.702 (s, 3H, SiꢁMe), and 5.7–6.7 ppm
(m, 3H, vinyl). m/z (EI) 321 (38%, [MꢁMe]+), 301 (4%,
[MꢁCl]+), 213 (100%, [MꢁMe3SiClꢁMe]+), 105(5%,
[MꢁTsi]+). (Found: C, 46.4; H, 9.7. C13H33Si4Cl Calc.:
C, 46.4; H, 9.8%).
A mixture of TsiSi(CH3)(CHꢀCH2)Cl (1 g, 3 mmol),
KOCN (3.5 g, 44 mmol) in CH3CN (150 cm3) was
refluxed for 30 h. The mixture was treated with diethyl
ether and water, separated the organic layer, dried
(MgSO4), evaporated, and the residue recrystallised
from EtOH. (78%), m.p. 324°C. FTIR (KBr, cm−1),
3.7. Preparation of trisylisothiocyanatomethyl6inylsilane
TsiSi(CH3)(CHꢀCH2)NCS
1
(SiꢁNCO) 2284, H-NMR (CDCl3): 0.277 (s, 27H, Tsi),
A mixture of TsiSi(CH3)(CHꢀCH2)Cl (1 g, 3 mmol),
KSCN (3.5 g, 36 mmol) in CH3CN (150 cm3), was
refluxed for 3 h. The mixture was treated with
petroleum ether and water, and the organic layer sepa-
rated, dried (MgSO4), evaporated and the residue was
recrystallised from EtOH. (80%), m.p. 308°C. FTIR
0.52 (s, 3H, SiꢁMe) and 5.5–6.5 ppm (m, 3H, vinyl).
m/z (EI): 328 (15%, [MꢁMe]+), 285 (10%,
[MꢁNCOꢁCH4]+), 240 (20%, [MꢁMe3Siꢁ2Me]+), 213
(58%, [MꢁMe3SiNCOꢁMe]+), 201 (20%, [MꢁTsiꢁ
2Me]+). (Found: C, 47.2; H, 9.5; N, 3.9, C14H33Si3NO
Calc.: C, 49.1; H, 9.6; N, 4%).
1
(KBr, cm−1), (SiꢁNCS), 2076, H NMR (CDCl3): 0.29
(s, 27H, Tsi), 0.567 (s, 3H, SiꢁMe) and 5.7–6.3 ppm (m,
3H, vinyl). m/z (EI): 344 (98%, [MꢁMe]+), 301 (2%,
[MꢁNCS]+) 285 (39%, [MꢁMe3Si]+), 256 (15%,
[MꢁMe3SiꢁMe]+), 213 (46%, [Mꢁ(Me3Si)2]+), 154
(19%, [Mꢁ(Me3Si)2ꢁNCS]+). (Found: C, 46.2; H, 8.9;
N, 3.7. C14H33Si3NS Calc.: C, 46.9; H, 9.2; N, 3.9%).
3.11. Preparation of trisyl(p-methylphenyl)methylsilane
TsiSi(C6H4Me-p)MeH
(C6H4Me-p)SiMeHCl (8.52 g, 50 mmol) was added
dropwise with stirring to
a
solution of TsiLi
(50mmol)in THF (100 cm3) that had been made by
reaction of TsiH (11.5 g, 60 mmol) with MeLi (0.84 g,
120 mmol). The mixture was refluxed for 4 h. The
aqueous NH4Cl was added and the organic compound
was extracted with Et2O.The extract was dried
(MgSO4), filtered, evaporated, and the residue recrys-
tallised from EtOH and was purified with preparative
3.8. Preparation of trisylazidomethyl6inylsilane
TsiSi(CH3)(CHꢀCH2)N3
A mixture of TsiSi(CH3)(CHꢀCH2)Cl (1 g, 3 mmol),
NaN3 (2.8 g, 43.4 mmol) in CH3CN (150 cm3) was

K.D. Safa et al. / Journal of Organometallic Chemistry 598 (2000) 222–227
225
TLC (silica gel, n-hexane as eluant), (45%), m.p. 107–
108°C. FTIR (KBr, cm−1), (SiꢁH) 2107.7, 1H-NMR
(CDCl3) 0.21 (s, 27H, Tsi), 0.44 (d, 3H, SiꢁMe), 2.33 (s,
3H, Meꢁaryl), 4.58 (q, 1H, SiꢁH), 7.06–7.66 ppm (m,
4H, aryl-H). m/z (EI) 366 (2%, [M]+), 365 (4%,
[MꢁH]+), 351 (18%, [MꢁMe]+), 275 (5%, [Mꢁtolyl]+),
261 (22%, [MꢁtolylꢁMe]+), 73(100), 45 (18). (Found: C,
58.5; H, 10.2. C18H38Si4 Calc.: C, 59.0; H, 10.3%).
(10%, [MꢁSCN]+), 347 (30%, [MꢁPh]+), 201 (18%,
[MꢁtolylꢁMe3SiꢁSCN]+). (Found: C, 53.8; H, 8.7; N,
3.4. C19H37NSi4 Calc.: C, 53.9; H, 8.7; N, 3.3%).
3.15. Preparation of trisylbutyldichlorosilane
TsiSiBuCl2
n-BuSiCl3 (9.575 g, 50 mmol) was added dropwise
with stirring to a solution of TsiLi (50 mmol) in THF
(50 cm3) that had been made by reaction of TsiH (11.5
g, 50 mmol) with MeLi (0.84 g, 120 mmol). The mix-
ture was refluxed for 30 min, then aqueous NH4Cl was
added and the organic layer was extracted with Et2O.
The extract was dried (MgSO4), filtered, evaporated,
and the residue recrystallised from EtOH. A pure
product was obtained by preparative TLC (silica gel,
hexane as eluant) to give TsiSiBuCl2 (48%), m.p. 119°C.
FTIR (KBr, cm−1), (CꢁH aliphatic) 2961.2, (CꢁSi)
3.12. Preparation of trisyl(p-methylphenyl)-
methyliodosilane TsiSi(C6H4Me-p)MeI
A solution of iodine monochloride (0.24 g, 1.4
mmol), in carbon tetrachloride (20 cm3), was added
dropwise to TsiSi(C6H4Me-p)MeH (0.5 g, 10 mmol) in
carbon tetrachloride (10 cm3) at room temperature.
When the addition was complete, the solvent was re-
moved and the solid residue was recrystallised from
EtOH to yield TsiSi(C6H4Me-p)MeI, (90%), m.p.
1
1250, 850, (SiꢁCl) 675.2, H-NMR (CDCl3) 0.347 (s,
1
179°C. FTIR (KBr, cm−1), (CꢁSi) 1245, 850, H-NMR
27H, Tsi) and 0.4–1.5 ppm (m, 9H, Bu). m/z (EI): 386
(5%, [M]+), 371 (95%, [MꢁMe]+), 315 (65%, [Mꢁ2Cl]+),
221 (70), 73 (87), 45 (38). (Found: C, 42.6; H, 9.3.
C10H36Cl2Si4 Calc.: C, 43.1; H, 9.3%).
(CDCl3), 0.328 (s, 27H, Tsi), 1.38 (s, 3H, MeꢁSi) and
2.35 ppm (s, 3H, MeꢁAryl). m/z (EI): 477(10%,
[MꢁMe]+), 386 (5%, [MꢁMeꢁtolyl]+), 365 (90%,
[MꢁI]+). (Found: C, 44.4; H, 7.6. C18H37ISi4 Calc.: C,
43.9; H, 7.5%).
3.16. Preparation of trisylbutyldiisothiocyanatosilane
TsiSiBu(SCN)2
3.13. Preparation of trisyl(p-methylphenyl)-
hydroxymethylsilane TsiSi(C6H4Me-p)MeOH
A mixture of TsiSiBuCl2 (1.5 g, 3.8 mmol), KSCN
(3.5 g, 36 mmol) and CH3CN (100 cm3) was refluxed
for 48 h. The mixture was treated with water and Et2O,
the organic layer separated, dried (MgSO4), and evapo-
rated. A pure product was obtained by preparative
TLC (silica gel, n-hexane as eluent), (60%), m.p. 100°C.
A mixture of TsiSi(C6H4Me-p)MeI (0.5 g, 1.3 mmol),
DMSO (25 cm3), H2O (4 cm3), and CH3CN (12 cm3)
was refluxed for 24 h. The solution was treated with
water and petroleum ether, dried (Na2SO4) and evapo-
rated. A pure product was obtained by preparative
TLC (silica gel, 1:1, cyclohexane: dichloromethane as
eluant), (75%), m.p. 150°C. FTIR (KBr, cm−1),
1
FTIR (KBr, cm−1), (SiꢁNCS)2100, H-NMR (CDCl3)
0.348 (s, 27H, Tsi), and 0.5–1.5 ppm (m, 9H, Bu). m/z
(EI): 417 (100%, [MꢁMe]+), 374 (60%, [MꢁSCN]+),
361 (20), 244 (42), 73 (82), 45 (10). (Found: C, 44.1; H,
8.5; N, 6.0. C16H36S2N2Si4 Calc.: C, 44.4; H, 8.3; N,
6.0%).
1
(SiꢁOH) 3600, (CꢁSi) 1245, H-NMR (CDCl3) 0.25 (s,
27H, Tsi), 0.59 (s, 3H, MeꢁSi), 1.76 (s, b, 1H, OH), 2.34
(s, 3H, Meꢁaryl) and 7.0–7.7 ppm (m, 4H, arylꢁH).
m/z (EI): 367 (30%, [MꢁMe]+), 352 (18%,
[MꢁMeꢁtolyl]+). (Found: C, 56.6; H, 9.9. C18H38OSi4
Calc.: C, 56.5; H, 9.9%).
3.17. Preparation of trisylbutyldiazidosilane
TsiSiBu(N3)2
3.14. Preparation of trisyl (p-methylphenyl)-
methylisothiocyanatosilane TsiSi(C6H4Me-p)MeNCS
A mixture of TsiSiBuCl2 (1.5 g, 3.8 mmol) and NaN3
(2.8 g, 43.4 mmol) in CH3CN (100 cm3) was refluxed
for 96 h. The mixture was treated with n-hexane and
water, the organic layer was separated, dried (MgSO4),
evaporated, and the residue recrystallised from EtOH.
A pure product was obtained by preparative TLC
(silica gel, n-hexane as eluant), (40%), m.p. 136°C.
A mixture of TsiSi(C6H4Me-p)MeI (0.5 g, 1.1 mmol)
with KSCN (1 g, 10 mmol) in CH3CN (50 cm3) was
refluxed for 10 days. Then it was treated with water and
petroleum ether (40–60), the organic layer separated,
dried (Na2SO4) and evaporated. The residue recrys-
tallised from EtOH. (70%), m.p. 128°C. FTIR (KBr,
1
FTIR (KBr, cm−1), (SiꢁN3) 2120, H-NMR (CDCl3)
0.304 (s, 27H, Tsi) and 0.5–1.5 ppm (m, 9H, Bu). m/z
(EI): 385.5 (18%, [MꢁMe]+), 358.5 (100%, [MꢁN3]+),
330 (25), 172 (40), 73 (30), 45 (5). (Found: C, 40.3; H,
9.0; N, 20.4. C14H36N6Si4 Calc.: C, 41.9; H, 9.0; N,
20.9%).
1
cm−1), (SiꢁNCS) 2080, (SiꢁC) 1245, H-NMR (CDCl3)
0.27 (s, 27H, Tsi), 0.73 (s, 3H, MeꢁSi), and 2.36 ppm (s,
3H, Meꢁtolyl). m/z (EI): 408 (20%, [MꢁMe]+), 350
(35%, [MꢁMe3Si]+), 377 (5%, [Mꢁ2(Me3Si)]+), 365

226
K.D. Safa et al. / Journal of Organometallic Chemistry 598 (2000) 222–227
3.18. Preparation of trisyl (p-methoxy phenyl)
methylsilane TsiSi (C6H4OMe-p)MeH
3.21. Preparation of trisyldichloro
(p-methoxyphenyl)silane TsiSi (C6H4OMe-p)Cl2
(C6H4OMe-p)SiMeHCl (9.3 g, 50 mmol) was added
dropwise with stirring to a solution of TsiLi (50 mmol)
in THF (100 cm3) that had been made by reaction of
TsiH (11.5 g, 60 mmol) with MeLi (0.84 g, 120 mmol).
The mixture was refluxed for 4 h, the aqueous NH4Cl
was added and the organic material was extracted with
Et2O. The extract dried (Na2SO4), filtered and evapo-
rated, and the residue recrystallised from EtOH, then
was purified by preparative TLC (silica gel, n-hexane as
eluant), (40%) m.p. 107–108°C. FTIR (KBr, cm−1),
(C6H4OMe-p)SiCl3 (12 g, 50 mmol) was added drop-
wise with stirring to a solution of TsiLi (50 mmol) in
THF (100 cm3) that had been made by reaction of TsiH
(11.5 g, 50 mmol) with Li (0.84 g, 120 mmol). The
mixture was refluxed for 4 h, the aqueous NH4Cl was
added and the organic material was extracted with
Et2O. The extract dried (Na2SO4), filtered, evaporated
and the residue recrystallised from EtOH, then sub-
limed at 100°C/0.1 mmHg, (60%) m.p. 165°C. FTIR
(KBr, cm−1), (SiꢁC) 1245, 1H-NMR (CDCl3) 0.3160 (s,
27H, Tsi), 3.8254 (s, 3H, OMeꢁanisole), 6.9261 (m, 4H,
C6H4). m/z (EI): 368 (5%, [M]+), 367 (1.3%, [MꢁH]+),
353 (96%, [MꢁMe]+), 351 (85%, [MꢁMeꢁ2H]+), 337
(4%, [MꢁOMe]+), 277(35%, [Mꢁ(Me3Si)ꢁCH4ꢁ2H]+),
260 (25%, [MꢁArꢁH]+), 187 (16%, [Mꢁ3(Me3Si)ꢁ
ArꢁH]+). (Found: C, 46.5; H, 7.8. C17H34Cl2OSi4
Calc.: C, 46.6; H, 7.8%).
1
(SiꢁH) 2107.7, H-NMR (CDCl3) 0.19 (s, 27 H, Tsi),
and 0.42 (d, 3H, MeꢁSi), and 3.79 (s, 3H,
MeOꢁanisole), and 4.57 (q, 1H, SiꢁH), and 6.50–7.50
(m, 4 H, arylꢁH). m/z (EI): 382 (5%, [M]+), 367 (58%,
[MꢁMe]+), 274 (35%, [Mꢁanisole]+), 260 (5%,
[MꢁanisoleꢁMe]+), 201 (27%, [MꢁanisoleꢁSiMe3]+).
(Found: C, 54.0; H, 10.0. C18H38OSi4 Calc.: C, 56.5; H,
9.9%).
3.22. Preparation of trisyldiisothiocyanato-
(p-methoxyphenyl)silane TsiSi(C6H4OMe-p)(NCS)2
3.19. Preparation of trisyl (p-methoxyphenyl)
methyliodosilane TsiSi (C6H4OMe-p)MeI
A mixture of TsiSi (C6H4OMe-p)Cl2 (0.3 g, 0.6
mmol), KSCN (0.1 g, 1 mmol) and CH3CN (50 cm3)
was refluxed for 10 days. Then was treated with water
and petroleum ether (40–60), the organic layer sepa-
rated, dried (Na2SO4) and evaporated. The residue
recrystallised from EtOH (40%) m.p. 130°C. FTIR
A solution of iodine monochloride (0.93 g, 6 mmol)
in carbon tetrachloride (10 cm3) was added dropwise to
one of TsiSi(C6H4OMe-p)MeH (1.4 g, 4 mmol) in
carbon tetrachloride (20 cm3) at room temperature.
When the addition was complete the solvent was re-
moved and the solid product was recrystallised from
EtOH to yield TsiSi(C6H4OMe-p)MeI (90%), m.p.
182°C. FTIR (KBr, cm−1), (SiꢁC) 1245, 1H-NMR
(CDCl3) 0.22 (s, 27H, Tsi), 1.30 (s, 3H, SiꢁMe), 3.70 (s,
3H, MeOꢁanisole), and 6.5–7.5 ppm (m, 4H, arylꢁH).
m/z (EI): 493 (4%, [MꢁMe]+), 401 (15%, [Mꢁanisole]+
), 381 (65%, [MꢁI]+), 366 (8%, [MꢁMeꢁI]+), 362 (7%,
[MꢁMeꢁ3(Me3Si)]+), 277 (12%, [MꢁTsi]+). (Found: C,
42.3; H, 7.3. C18H37IOSi4 Calc.: C, 42.5; H, 7.3%).
1
(KBr, cm−1), (SiꢁNCS) 2070, (SiꢁC) 1245, H-NMR
(CDCl3) 0.2398 (s, 27H, Tsi), 3.7920 (s, 3H,
MeOꢁanisole), and 6.8–7.8 ppm (m,4H, arylꢁH). m/z
(EI): 482 (3%, [M]+), 467 (33%, [MꢁMe]+), 409 (28%,
[MꢁSCNꢁMe]+), 351 (5% [Mꢁ(SCN)2ꢁMe]+). (Found:
C, 46.6; H, 7.8; N, 5.8. C19H34N2OS2Si4 Calc.: C, 47.3;
H, 7.00; N, 5.8%).
Acknowledgements
3.20. Preparation of trisyl (p-methoxyphenyl)-
methylisothiosyanato silane TsiSi(C6H4OMe-p)MeNCS
We thank Dr P.D. Lickiss and Professor C. Eaborn
for helpful comments.
A mixture of TsiSi (C6H4OMe-p)MeI (0.1 g, 1
mmol), KSCN (0.1 g, 1 mmol) and CH3CN (50 cm3)
was refluxed for 10 days, then was treated with water
and petroleum ether (40–60), the organic layer seper-
ated, dried (Na2SO4) and evaporated. The residue re-
crystallised from EtOH (50%).m.p. 130°C. FTIR (KBr,
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[MꢁOMe]+), 381 (20%, [MꢁSCN]+), 366 (14%,
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