Reactions of bis(phenylethynyl)ytterbium with trimethylsilicon, triphenylgermanium, and triphenyltin chlorides

Article abstract of DOI:10.1023/B:RUGC.0000007638.44196.89

The ytterbium phenylethynyl compound (PhC=C)₂Yb(THF)₄ reacts with trimethylsilicon, triphenylgermanium, and triphenyltin chloride in tetrahydrofuran (THF) at room temperature to give the corresponding cross-coupling products: phenyle

Full text of DOI:10.1023/B:RUGC.0000007638.44196.89

Russian Journal of General Chemistry, Vol. 73, No. 8, 2003, pp. 1188 1189. Translated from Zhurnal Obshchei Khimii, Vol. 73, No. 8, 2003,
pp. 1258 1260.
Original Russian Text Copyright
2003 by Pimanova, Zhil’tsov, Druzhkova.
Reactions of Bis(phenylethynyl)ytterbium with Trimethylsilicon,
Triphenylgermanium, and Triphenyltin Chlorides
N. A. Pimanova, S. F. Zhil’tsov, and O. N. Druzhkova
Nizhny Novgorod State Pedagogical University, Nizhny Novgorod, Russia
Received July 20, 2001
Abstract The ytterbium phenylethynyl compound (PhC C)2Yb(THF)4 reacts with trimethylsilicon, tri-
phenylgermanium, and triphenyltin chloride in tetrahydrofuran (THF) at room temperature to give the cor-
responding cross-coupling products: phenylethynylytterbium chloride PhC CYbCl(THF)2 and ytterbium
chloride YbCl2(THF)2.
We have reported previously [1] that the most
convenient synthetic route to homoleptic phenylethyn-
yl derivatives of lanthanides is reaction of phenyl-
ethynylsodium with rare-earth metal iodides. The
resulting compounds were isolated pure. They are
highly reactive [2, 3]. In particular, it is known [4 6]
that organolanthanide analogs of Grignard reagents,
RLnX (R = alkyl, aryl; Ln = Yb, Eu, Sm, Ce; X = I,
Br, Cl), prepared in situ, react with trimethylsilicon
and triphenyltin chlorides, as well as with alkyl and
aryl halides, in the presence of palladium and nickel
complexes to give the cross-coupling products in high
yields:
THF
(PhC C)2Yb(THF)4 + R3ECl
R3EC CPh
R3EC CPh
+ (PhC C)YbCl(THF)2,
THF
(PhC C)YbCl(THF)2 + R3ECl
+ YbCl2(THF)2.
As seen from the table, bis(phenylethynyl)ytterbi-
um is dealkynylated most readily under the action of
trimethylsilicon chloride. Replacement of the methyl
group by phenyl (Ph3GeCl, Ph3SnCl) results in de-
creased yield of ytterbium chloride. The yield of the
cross-coupling product decreases also.
Pd(PPh3)4
PhLnX + R I
Ph R + LnXI.
Thus, bis(phenylethynyl)ytterbium reacts with tri-
methylsilicon, triphenylgermanium, and triphenyltin
chlorides under mild conditions without a catalyst,
giving cross-coupling products in high yields.
THF, 25 C
In this study, we examined the reactivity of lantha-
nide phenylethynyl derivatives. As an example, we
chose the reactions of bis(phenylethynyl)ytterbium
with mixed organometallic compounds R3ECl (R =
CH3, Ph; E = Si, Ge, Sn).
EXPERIMENTAL
All manipulations with air- and moisture-sensitive
compounds were performed in evacuated sealed am-
We found that bis(phenylethynyl)ytterbium reacts
with trimethylsilicon, triphenylgermanium, and tri-
phenyltin chlorides in THF at room temperature even
in the course of mixing the reactants. The mixture,
however, was allowed to stand for 24 h to bring the
reaction to completion. As seen from the table, the
major reaction products are the corresponding unsym-
metrical organic derivatives of silicon, germanium,
and tin (cross-coupling products), phenylethynyl-
ytterbium chloride PhC CYbCl(THF)2, and ytterbium
chloride YbCl2(THF)2.
Reactions of bis(phenylethynyl)ytterbium with R3ECl
(E = Si, Ge, Sn; R = CH3, C6H5; molar ratio 1 : 2) in THF
at room temperature for 24 h
R3ECl Reaction products, moles per mole of starting
(PhC C)2Yb(THF)4
PhC CER3 PhC CYbCl(THF)2 YbCl2(THF)2
Me3SiCl
Ph3GeCl
Ph3SnCl
1.90
1.35
1.36
0.15
0.64
0.40
0.85
0.33
0.39
The mechanism of formation of the reaction prod-
ucts apparently involves stepwise dealkynylation of
the organolanthanide compound.
1070-3632/03/7308-1188$25.00 2003 MAIK Nauka/Interperiodica

REACTIONS OF BIS(PHENYLETHYNYL)YTTERBIUM WITH TRIMETHYLSILICON
1189
pules using thoroughly dried and degassed solvents.
The IR spectra were recorded on an IKS-25 spectrom-
eter; samples were prepared as mulls in mineral oil
under argon. The ytterbium phenylethynyl derivative
was prepared by the reaction of ytterbium diiodide
with phenylethynylsodium in THF. The melting (or
decomposition) points of the starting compounds and
reaction products were determined in sealed capillaries
(the uncorrected values are given).
9.48; Yb 41.93. C16H21O2YbCl. Calculated, %: C
42.33; H 4.63; Cl 9.30; Yb 45.34.
From the combined hexane extracts, the solvent
was evaporated, and 0.26 g of Ph3GeC CPh was ob-
tained as a white air-stable crystalline substance,
mp 84 C, readily soluble in THF, benzene, and hex-
1
ane. IR spectrum, , cm : 3040 s, 2165 s (C C),
1480 s, 1425 m, 1085 s, 1065 w, 1020 w, 995 m,
730 s, 690 s, 460 s. Found, %: C 74.10; H 6.04.
C26H20Ge. Calculated, %: C 74.45; H 6.56.
Reaction of (PhC C)2Yb(THF)4 with Me3SiCl.
An 0.40-g portion of Me3SiCl was added to a solution
of 0.81 g of (PhC C)2Yb(THF)4 in 30 ml of THF.
The solution changed color, and a precipitate formed.
The mixture was allowed to stand for a day at room
temperature. The solvent was vacuum-evaporated, and
the residue was treated with hexane. The precipitate
formed in THF contained 0.54 g of YbCl2(THF)2, a
light yellow substance unstable in air and insoluble
in THF and hexane; mp >350 C. Found, %: Cl 15.46;
Yb 41.68. C8H16Cl2O2Yb. Calculated, %: Cl 18.29;
Yb 44.58.
Reaction of (PhC C)2Yb(THF)4 with Ph3SnCl.
A 0.50-g portion of Ph3SnCl was added to a solution
of 0.43 g of (PhC C)2Yb(THF)4 in 30 ml of THF.
The mixture was allowed to stand for a day at room
temperature, the solvent was vacuum-evaporated, and
the residue was treated with hexane. The precipitate
formed in THF contained 0.10 g of YbCl2(THF)2.
Found, %: Cl 20.02; Yb 42.98, C8H16O2YbCl2. Cal-
culated, %: Cl 18.29; Yb 44.58.
The yellow solid insoluble in hexane was vacuum-
dried for 1 h at room temperature; 0.12 g of PhC C
YbCl(THF)2. was obtained. Its IR spectrum coincided
with that of the similar product obtained in the reac-
tion with Me3SiCl. Found, %: Cl 5.48; Yb 36.33.
C16H21O2YbCl. Calculated, %: Cl 7.82; Yb 38.14.
The yellow solid insoluble in hexane was vacuum-
dried for 1 h at room temperature; 0.10 g of PhC C
YbCl(THF)2 was obtained as a yellow amorphous
substance, mp 285 290 C, sensitive to atmospheric
oxygen and moisture, soluble in THF and benzene,
1
and insoluble in hexane. IR spectrum, , cm : 2200
From the combined hexane extracts, the solvent
was slowly evaporated, and 0.39 g of Ph3SnC CPh
was obtained as a colorless air-stable crystalline sub-
stance, mp 62 C (in agreement with published data
[7]), readily soluble in THF, benzene, and hexane.
Found, %: C 69.53; H 4.39. C26H20Sn. Calculated,
%: C 69.33; H 4.44.
m (PhC C), 2050 m (C C), 1880 w, 1790 w, 1445 s,
1380 s, 1300 s, 1070 m, 1025 s, 995 s, 730 m, 670 s,
490 m; 1040 m, 840 m (coordinated THF). Found, %:
Cl 6.48; Yb 37.23; C16H21ClO2Yb. Calculated, %:
Cl 7.82; Yb 38.14.
From the combined hexane extracts, the solvent
was slowly removed, and 0.46 g of Me3SiC CPh was
obtained as an air-stable yellow oily substance, bp
82 C (6 mm) [5], readily soluble in THF, benzene,
and hexane. Found, %: C 75.36; H 7.90. C11H14Si.
Calculated, %: C 75.86; H 8.04.
REFERENCES
1. Druzhkova, O.N., Pimanova, N.A., and Bochkarev, L.N.,
Zh. Obshch. Khim., 1999, vol. 69, no. 11, p. 1801.
2. Shustov, S.B., Bochkarev, L.N., and Zhil’tsov, S.F.,
Metalloorg. Khim., 1990, vol. 3, no. 3, p. 624.
3. Zhil’tsov, S.F, Shustov, S.B., and Shustova, L.V.,
Metalloorg. Khim., 1992, vol. 5, no. 4, p. 729.
Reaction of (PhC C)2Yb(THF)4 with Ph3GeCl.
An 0.34-g portion of Ph3GeCl was added to a solution
of 0.32 g of (PhC C)2Yb(THF)4 in 30 ml of THF.
The mixture was allowed to stand for a day at room
temperature, the solvent was vacuum-evaporated, and
the residue was treated with hexane. The precipitate
formed in THF contained 0.063 g of YbCl2(THF)2.
Found, %: Cl 23.09; Yb 40.68. C8H16Cl2O2Yb. Cal-
culated, %: Cl 18.29; Yb 44.58.
4. Rybakova, L.F., Syutkina, O.P., Petrov, E.S., Shifri-
na, R.R., and Beletskaya, I.P., Izv. Akad. Nauk SSSR,
Ser. Khim., 1984, no. 6, p. 1413.
5. Gailyunas, G.A., Biktimirov, R.Kh., Nurtdinova, G.V.,
Monakov, Yu.B., and Tolstikov, G.A., Izv. Akad. Nauk
SSSR, Ser. Khim., 1984, no. 6, p. 1435.
6. Rybakova, L.F., Syutkina, O.P., Garbar, A.V., and Pet-
rov, E.S., Zh. Obshch. Khim., 1988, vol. 58, no. 5,
p. 1053.
The yellow solid insoluble in hexane was vacuum-
dried for 1 h at room temperature; 0.12 g of PhC C
YbCl(THF)2 was obtained. Its IR spectrum coincided
with that of the similar product obtained in the reac-
tion with Me3SiCl. Found, %: C 42.44; H 4.47; Cl
7. Hartmann, H. and Honig, H., Angew. Chem., 1957,
vol. 69, no. 18/19, p. 614.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 73 No. 8 2003