Convenient syntheses of aryl and perfluoroaryl trichlorogermanes and germatranes via an organotin route

Article abstract of DOI:10.1021/om0400189

Aryl- and (perfluoroaryl)trichlorogermanes ArGeCl₃(Ar = C ₆H₅, 2-FC₆H₄, 3,5-(CF ₃)₂C₆H₃, C₆F₅, 2,3,5,6-F₄C₅N) are easily obtained in 60-80% yields from the corresponding tributyl-stannanes and GeCl₄ (1:1) at 150 °C in the absence of a solvent. Although the tin-to-germanium transmetalation of C₆F₅ group is sluggish, it is facilitated by addition of 1-2 mol % AIBN (2,2′-azobis(isobutyronitrile)).

Full text of DOI:10.1021/om0400189

3184
Organometallics 2004, 23, 3184-3188
Con ven ien t Syn th eses of Ar yl a n d P er flu or oa r yl
Tr ich lor oger m a n es a n d Ger m a tr a n es via a n
Or ga n otin Rou te
Roman G. Kultyshev,† G. K. Surya Prakash,*,† George A. Olah,*,†
J ack W. Faller,‡ and J onathan Parr‡
Loker Hydrocarbon Research Institute and Department of Chemistry, University of Southern
California, 837 Bloom Walk, Los Angeles, California 90089, and Department of Chemistry,
Yale University, 225 Prospect Street, New Haven, Connecticut 06520
Received February 18, 2004
Aryl- and (perfluoroaryl)trichlorogermanes ArGeCl3 (Ar ) C6H5, 2-FC6H4, 3,5-(CF3)2C6H3,
C6F5, 2,3,5,6-F4C5N) are easily obtained in 60-80% yields from the corresponding tributyl-
stannanes and GeCl4 (1:1) at 150 °C in the absence of a solvent. Although the tin-to-
germanium transmetalation of C6F5 group is sluggish, it is facilitated by addition of 1-2
mol % AIBN (2,2′-azobis(isobutyronitrile)).
Ta ble 1. Rea ction of Ar yl Tr ibu tylsta n n a n es 1a -e
w ith GeCl4 (1:1) a t 150 °C
Recently there has been an interest in developing
germanium-based reagents for organic synthesis.1 In
particular, in palladium-catalyzed cross-coupling reac-
tions aryltri-2-furylgermanes have been shown to be
viable reagents for biaryl synthesis,1b while carba-1a and
oxagermatranes1c,d have been applied with various
degrees of success to the arylation, allylation, alkenyl-
ation, and ethynylation of aryl halides and triflates. Due
to our interest in the cross-coupling reactions of arylger-
matranes, we were looking for a convenient method of
synthesis of C6H5GeCl3 (2a ). Although it is commercially
available,2 it is quite expensive. Many of the reported
methods of its synthesis can hardly be employed in a
typical chemistry laboratory, due to the necessity of
using high temperature and pressure3a,b and/or reagents
that are not readily available.3c The method involving
transmetalation between diaryl mercurials and german-
ium tetrachloride works but suffers from the necessity
of dealing with presumably higly toxic compounds, as
well as the fact that only one aryl group is utilized.3d,e
The apparently straightforward route via reaction of
germanium tetrachloride with aryl iodides in the pres-
ence of copper was reported3f to fail when substituent-
(s) were introduced in the aromatic ring.
AIBN,
mol %
reacn
isolated yield
of ArGeCl3, %
entry
n-Bu3SnAr
C6H5, 1a
C6H5, 1a
C6F5, 1b
2,3,5,6-F4C5N, 1c
2,3,5,6-F4C5N, 1c
2-FC6H4, 1d
3,5-(CF3)2C6H3, 1e
3,5-(CF3)2C6H3, 1e
3,5-(CF3)2C6H3, 1e
time, h
1
2
3
4
5
6
7
8
9
12
22
33
5
13
12
15
15
12
76
76
73
72
69
60
59a
57a
70
2.1
1.3
2.1
2.0
a
Stannane not distilled prior to reaction.
Sch em e 1
germanes, it was only logical to extend these studies to
the transfer of aryl groups. Preliminary experiments
with n-Bu3SnC6H5 (1a ) and GeCl4 demonstrated that
the phenyl group transfer has to be carried out at a
higher temperature than those of the unsaturated
groups above. Heating the mixture of 1a and GeCl4 (1:
1) at 150 °C for 18 h resulted in complete conversion to
2a , which was isolated in 72% yield after vacuum
distillation. Neither the reduction of reaction time to
12 h nor addition of AIBN had significant impact on the
isolated yield of 2a (Table 1, entries 1 and 2). According
to the standard procedure5 2a was converted to phen-
Since transmetalation from tin to germanium had
been previously used for the syntheses of alkenyl,4a,b
alkynyl,4c,d propargyl,4e and various allylic4f trichloro-
* To whom correspondence should be addressed. E-mail: gprakash@
usc.edu (G.K.S.P.).
† University of Southern California.
‡ Yale University.
(1) (a) Kosugi, M.; Tanji, T.; Tanaka, Y.; Yoshida, A.; Fugami, K.;
Kameyama, M.; Migita, T. J . Organomet. Chem. 1996, 508, 255. (b)
Nakamura, T.; Kinoshita, H.; Shinokubo, H.; Oshima, K. Org. Lett.
2002, 4, 3165. (c) Faller, J . W.; Kultyshev, R. G. Organometallics 2002,
21, 5911. (d) Faller, J . W.; Kultyshev, R. G.; Parr, J . Tetrahedron Lett.
2003, 44, 451.
(2) For example, the Sigma-Aldrich price is $37.50 per gram.
(3) (a) Okamoto, M.; Asano, T.; Suzuki, E. Organometallics 2001,
20, 5583. (b) Chernyshev, E. A.; Komalenkova, N. G.; Yakovleva, G.
N.; Bykovchenko, V. G. Zh. Obshch. Khim. 1995, 65, 1869. (c)
Poskozim, P. S. J . Organomet. Chem. 1968, 12, 115. (d) Orndorff, W.
H.; Tabern, D. L.; Dennis, L. M. J . Am. Chem. Soc. 1927, 49, 2512. (e)
Seyferth, D.; Hetflejs, J . J . Organomet. Chem. 1968, 11, 253. (f)
Mironov, V. F.; Fedotov, N. S. Zh. Obshch. Khim. 1966, 36, 556.
(4) (a) Mironov, V. F.; Nuridzhanyan, A. K. Metalloorg. Khim. 1992,
5, 705. (b) Guillemin, J .-C.; Lassalle, L.; J anati, T. Planet. Space Sci.
1995, 43, 75. (c) Sharanina, L. G.; Zavgorodnii, V. S.; Petrov, A. A. Zh.
Obshch. Khim. 1966, 36, 1154. (d) Chrostowska, A.; Metail, V.; Pfister-
Guillouzo, G.; Guillemin, J .-C. J . Organomet. Chem. 1998, 570, 175.
(e) Guillemin, J .-C.; Malagu, K. Organometallics 1999, 18, 5259. (f)
Faller, J . W.; Kultyshev, R. G.; Parr, J . J . Organomet. Chem., accepted
for publication.
10.1021/om0400189 CCC: $27.50 © 2004 American Chemical Society
Publication on Web 05/18/2004

Trichlorogermanes and Germatranes
Organometallics, Vol. 23, No. 13, 2004 3185
ylgermatrane 3a , which was isolated in 93% yield
(Scheme 1).
It was of interest to explore the possibility of the
analogous pentafluorophenyl group transfer paving the
way to the preparation of C6F5Ge(OCH2CH2)3N (3b) and
its evaluation as a possible C6F5 transfer reagent. The
synthesis of C6F5GeCl3 (2b) from GeCl4 is known to be
nontrivial. With C6F5Li, (C6F5)3GeCl is the major
product,6a while using C6F5MgBr results in a mixture
of C6F5GeCl3-nBrn (n ) 0-3).6b Although both 2b and
C6F5GeBr3 have been previously prepared by Bardin et
al.6c via transmetalation between C6F5HgEt and GeX4,
the yields were moderate, not to mention the drawback
of working with organomercury compounds. An alterna-
tive reaction between iodopentafluorobenzene and GeCl4
in the presence of copper at 250 °C resulted in only a
30% yield of 2b contaminated with decafluorobiphenyl.6c
The same authors have also studied the reaction
between Me3SnC6F5 and GeX4 (X ) Cl, Br) at 240 °C
and reported very low conversions for X ) Cl. Not
surprisingly, the reaction between n-Bu3SnC6F5 (1b)
and GeCl4 at 150 °C was found to be sluggish as well.
However, addition of AIBN (2 mol %) to the reaction
mixture led to significant improvement with respect to
the rate of the transmetalation. Thus, the 119Sn and 19F
NMR spectra taken after 32 h at 150 °C were free of
the signals of stannane 1b. Instead, a new signal
ascribable to n-Bu3SnCl in the 119Sn NMR and three
new signals in the 19F NMR spectra due to 2b indicated
the completeness of the pentafluorophenyl group trans-
fer according to eq 1. The same reaction without AIBN
F igu r e 1. ORTEP drawing of 3b.
Ta ble 2. Metr ica l Da ta for 3b a n d 3a
3b
3a
Ge-N, Å
2.156(2)
1.990(3)
1.789(2)
176.3(1)
0.2(3)
2.212(3)
1.950(4)
1.802(3)
177.3(2)
-18.3(3)
0.252
Ge-C1, Å
Ge-O (mean), Å
N-Ge-C, deg
O3-Ge-C1-C6, deg
C1-C6 plane to Ge, Å
C1-C6 plane to N, Å
0.061
0.188
0.622
GeCl4 + n-Bu3SnC6F5 f C6F5GeCl3 + n-Bu3SnCl
(1)
BuGeCl3 would be seen in the product mixture. Dis-
carding the lowest boiling fraction after the vacuum
distillation of the reaction mixture resulted in 3b
containing only traces of n-BuGe(OCH2CH2)3N. Ger-
matrane 3b was easily purified by recrystallization from
CH2Cl2-hexanes. The molecular structures of both 3b
and 3a were determined by single-crystal X-ray diffrac-
tion analysis at low temperature (Figure 1).7 Relevant
metrical data and crystallographic parameters are
reported in Tables 2 and 3 and in the Supporting
Information. Most notably, the N-Ge distance in 3b,
although shorter than that in 3a , falls somewhere in
the middle of the range reported8 for various ger-
matranes (2.01-2.29 Å), despite the strong electron-
withdrawing character of the C6F5 group. Within ex-
perimental error the perfluorophenyl ring is eclipsed
with a Ge-O bond in the solid state, whereas there is
an 18° twisting in the phenyl case. In 3a there is a
displacement of Ge and N out of the C1-C6 plane
(pointed out by Lukevics8). This is less pronounced in
the perfluorinated analogue 3b (Table 2).
is much slower. Thus, when two reactions were run in
parallel and checked after 23 h, almost all of the 1b
reacted in the presence of AIBN, while only about 25%
of 1b was consumed without AIBN. Trichlorogermane
2b isolated after vacuum distillation was converted to
germatrane 3b (Scheme 1). The latter was apparently
contaminated with another germatrane, as indicated by
characteristic methylene signals in its 1H NMR spec-
trum. GC-MS analysis of the distillate obtained from
the reaction mixture revealed the presence of a byprod-
uct, n-BuGeCl3 (m/z 200 (BuGeCl2+), 178 (GeCl3+), 165
(BuGeCl+), 143 (GeCl2+), 108 (GeCl+), 57 (C4H9+)). In
1
addition, n-BuGeCl3 was identified by its H3c and 13C
NMR spectra. The 2b to n-BuGeCl3 molar ratio in the
distillate, estimated from the integration of the meth-
ylene signals in the 1H NMR spectrum of the 3b/n-
BuGe(OCH2CH2)3N mixture, was 9:1. In contrast, only
1
a trace amount of n-BuGeCl3 was observed in the H
NMR spectrum after the phenyl transfer reaction. This
suggests the correlation between the ease of transmeta-
lation of an aryl group and the amount of n-BuGeCl3
formed as a byproduct. The rate of the n-Bu transfer
must be very slow compared to that of the phenyl group,
but as the aryl group becomes less prone to transmeta-
lation, the reaction time increases and more of n-
Another perfluoroaryl moiety readily available for the
tin-to-germanium transmetalation study is the 2,3,5,6-
tetrafluoropyridyl group. Two methods have been evalu-
ated for the synthesis of the corresponding tin precursor,
both using an exchange reaction with n-BuLi (Scheme
2). The reaction with 2,3,5,6-tetrafluoropyridine is
preferred, because it yields stannane n-Bu3SnC5NF4
(5) Gar, T. K.; Khromova, N. Yu.; Sonina, N. V.; Nikitin, V. S.;
Polyakova, M. V.; Mironov, V. F. Zh. Obshch. Khim. 1979, 49, 1516.
(6) (a) Fenton, D. E.; Massey, A. G.; Urch, D. S. J . Organomet. Chem.
1966, 6, 352. (b) Bochkarev, M. N.; Vyazankin, N. S.; Maiorova, L. P.;
Razuvaev, G. A. Zh. Obshch. Khim. 1978, 48, 2706. (c) Bardin, V. V.;
Aparina, L. N.; Furin, G. G. Zh. Obshch. Khim. 1991, 61, 1414.
(7) The room-temperature X-ray molecular structure of 3a has been
reported.8
(8) Lukevics, E.; Ignatovich, L.; Belyakov, S. J . Organomet. Chem.
1999, 588, 222.

3186 Organometallics, Vol. 23, No. 13, 2004
Kultyshev et al.
Ta ble 3. Cr ysta llogr a p h ic Da ta for 3b
the compounds ArGeCl3 and ArGe(OCH2CH2)3N in good
yields. The amount of n-BuGeCl3 formed as a byproduct
seems to indicate that the facility of transmetalation
decreases in the following order: C6H5 ≈ 2,3,5,6-F4C5N
> 3,5-(CF3)2C6H3 ≈ 2-FC6H4 . C6F5. In the C6F5 case
addition of AIBN (1-2 mol %) accelerates the reaction
considerably, making this route synthetically viable.
The scope of the reaction is obviously limited by the
availability of the precursor stannanes, as well as the
proximity of the boiling points of ArGeCl3 and n-Bu3-
SnCl, unless the separation from the latter can be
achieved by a method other than distillation.
color, shape
empirical formula
formula wt
radiation, λ/Å
T/K
colorless, needle
12H12F5GeNO3
385.81
Mo KR (monochr), 0.71073
183
C
cryst syst
space group
unit cell dimens
a/Å
monoclinic
P21/c (No. 14)
6.7491(2)
9.6839(3)
20.7819(7)
94.713(1)
1353.66(7)
4
1.893
23.33
0.037
b/Å
c/Å
â/deg
V/Å3
Z
D
calcd/g cm-3
µ/cm-1 (Mo KR)
Exp er im en ta l Section
Rint
no. of params, restraints
199, 0
0.033, 0.033, 1.06
-0.44, 0.39
Gen er a l In for m a tion . Ether and toluene were dried over
sodium/benzophenone and distilled prior to use. n-Bu3SnC6F5
was prepared according to the method of Deacon et al.10
Germanium tetrachloride, bromopentafluorobenzene (Strem),
2,3,5,6-tetrafluoropyridine (Lancaster), and all other reagents
(Aldrich) were used as received. NMR spectra were obtained
on Varian Unity 300 (1H, 299.9 MHz; 13C, 75.4 MHz; 19F, 282.2
MHz; 119Sn, 111.9 MHz) and Mercury 400 (1H, 400.1 MHz)
spectrometers. 1H NMR spectra were referenced versus re-
sidual CHCl3 in CDCl3 (7.27 ppm). 13C NMR spectra were
referenced versus CDCl3 (77.0 ppm). 19F spectra were refer-
enced externally to CFCl3 in CDCl3, and 119Sn spectra were
referenced externally to 50% (CH3)4Sn in CDCl3 (in both cases
δ 0.0 ppm). Coupling constants are reported in Hz. Hydrogen
atoms of the aryl substituent in 1d , 2d , and 3d are numbered
consecutively, starting with the atom nearest to tin or german-
ium and ending with the atom next to the fluorine. Elemental
analyses were performed by Atlantic Microlab, Inc. Trichlo-
rogermanes 2b-e were not analyzed, due to their tendency
toward hydrolysis. Instead, the high-resolution mass spectra
were obtained at the UCLA mass spectrometry facilities. The
1H NMR spectrum of 3a agreed with that reported in the
literature.8
R1,a wR2,b GOF
min, max resid density/e Å-3
a
b
2
R1 ) ∑||Fo| - |Fc||/∑|Fo|, for all I > 3σ(I). wR2 ) [∑[w(Fo
-
Fc2)2]/∑[w(Fo2)2]]1/2
.
Sch em e 2
(1c) in higher purity using a substantially cheaper
starting material.9 Transmetalation between 1c and
GeCl4 in the presence of AIBN was over in less than 5
h, leading to the isolation of 2,3,5,6-F4C5NGeCl3 (2c)
(Table 1, entry 4) containing only traces of n-BuGeCl3.
The ease of transmetalation prompted us to carry out
the same reaction without AIBN. According to the 19F
and 119Sn NMR spectra of the reaction mixture, there
was still some unreacted 1c left after 6 h. Additional
heating at 150 °C for 4 h resulted in complete disap-
pearance of the corresponding signals. Thus, although
in the presence of AIBN the transmetalation occurs
faster, the reaction without AIBN is still complete in
less than 10 h, a behavior very different from that of
the pentafluorophenyl group.
Gen er a l P r oced u r e for th e Syn th esis of Ar yltr ich lo-
r oger m a n es. A 17-20 cm heavy-walled pressure tube (Ace
Glass) equipped with a magnetic stirring bar was charged in
air with 5-10 mmol of an aryltributylstannane. Under a dry
argon atmosphere in a glovebox an equimolar amount of
germanium tetrachloride was added via a syringe. When
needed, AIBN (1-2 mol %) was added to the stannane prior
to the addition of GeCl4. The tube was sealed with a PTFE
cap and immersed in an oil bath that was preheated to 150
°C. After 5-33 h the tube was cooled to room temperature.
With CH2Cl2 its content was quickly transferred in air in a
distillation apparatus consisting of a 25 mL round-bottom
flask, 10 cm Vigreaux column, micro distillation head, ther-
mometer, and receiving flask. Without heating the flask, a
dynamic vacuum was applied slowly to remove the solvent.
After its removal and replacement of the receiving flask, three
to four fractions of aryltrichlorogermane were collected by
heating the 25 mL flask in an oil bath. The lowest boiling
fraction usually contained some n-BuGeCl3. The distillation
was stopped after an appreciable amount of n-Bu3SnCl could
be detected in the fraction being collected (usually more than
6-7 mol %).
Transmetalation of the partially fluorinated aryl
groups 2-FC6H4 and 3,5-(CF3)2C6H3 from tin to german-
ium did not seem to benefit from the use of AIBN. For
example, the yields of 2e were almost identical, regard-
less of the AIBN presence (Table 1, entries 7 and 8).
1
J udging by H NMR spectra of the crude products, the
amounts of n-BuGeCl3 formed in these reactions were
obviously higher than in the phenyl case, indicating that
partial fluorination results in reduced reactivity toward
transmetalation. The lower isolated yield of 2d relative
to 2e is probably due to the higher boiling point of the
former, resulting in its less efficient separation from
n-Bu3SnCl. Both 2-FC6H4Ge(OCH2CH2)3N (3d ) and 3,5-
(CF3)2C6H3Ge(OCH2CH2)3N (3e) obtained from the cor-
responding trichlorogermanes 2d and 2e were easily
purified by recrystallization.
(P en taflu or oph en yl)tr ich lor oger m an e (2b). GeCl4 (13.94
mmol), 1b (13.96 mmol), and AIBN (0.19 mmol) gave 10.14
mmol of 2b (73%) as a colorless liquid after vacuum distilla-
tion; bp 59-62 °C/ 4 mm (lit.6c bp 85-88 °C/20 mm). 19F{1H}
NMR (CDCl3): δ -126.7 (m, Fo), -143.4 (tt, 3J ) 19.9, 4J )
6.1, Fp), -157.7 (m, Fm).
In conclusion, transmetalation from tin to germanium
provides a convenient approach to the preparation of
(9) 2,3,5,6-Tetrafluoropyridine can be obtained from Lancaster for
$23.50 per gram.
(10) Deacon, G. B.; Gatehouse, B. M.; Nelson-Reed, K. T. J .
Organomet. Chem. 1989, 359, 267.

Trichlorogermanes and Germatranes
Organometallics, Vol. 23, No. 13, 2004 3187
(P en ta flu or op h en yl)ger m a tr a n e (3b). Triethanolamine
(9.57 mmol) and 2b (9.59 mmol) gave 8.62 mmol of 3b (90%)
as a white solid after recrystallization from CH2Cl2-hexanes;
mp 169-171 °C. 1H NMR (CDCl3, 300 MHz): δ 3.93 (t, 6H, 3J
) 5.7, CH2O), 2.98 (t, 6H, 3J ) 5.7, CH2N). 13C{1H} NMR
(CDCl3): δ 57.1, 52.1. 19F{1H} NMR (CDCl3): δ -125.1 (m,
phase was washed with a fresh portion of dichloromethane
followed by combining two organic phases, drying over MgSO4,
and filtering. The solvent was removed on the rotary evapora-
tor, leaving behind the crude product as an oil. Upon distil-
lation of this oil under vacuum using a 10 cm Vigreaux column,
three fractions were collected. The first fraction contained
significant amounts of impurities, while the other two yielded
3.955 g of clean 1d as a colorless oil (62%); bp 143-146 °C/6
mm (lit.11 127-130 °C/12 mm). 1H NMR (CDCl3, 300 MHz): δ
3
Fo), -153.7 (t, J ) 19.9, Fp), -161.9 (m, Fm). Anal. Calcd for
C
12H12O3F5NGe: C, 37.36; H, 3.14; N, 3.63; F, 24.62. Found:
C, 37.50; H, 3.12; N, 3.64; F, 24.35.
3
4
4
7.44 (ddd, 1H, J HH ) 6.9, J HF ) 3.9, J HH ) 2.0, H1), 7.38-
1-(Tr i-n -bu tylsta n n yl)-2,3,5,6-tetr a flu or op yr id in e (1c).
A 100 mL Schlenk flask equipped with a magnetic stirbar and
a rubber septum was charged under nitrogen with 40 mL of
dry ether, followed by 1.64 mL of 97% 2,3,5,6-tetrafluoropy-
ridine (15.8 mmol). The resulting solution was cooled to -78
°C, followed by addition of 6.40 mL of 2.47 M n-BuLi in
hexanes (15.8 mmol) within a 10 min period. The reaction
mixture was stirred for 25 min before 4.40 mL of 96% n-Bu3-
SnCl (15.6 mmol) was added within 5 min. After 1.5 h of
stirring at -78 °C, the flask was removed from the cold bath,
and the stirring was continued overnight (12 h) at room
temperature. The reaction mixture was transferred into a 250
mL round-bottom flask using ether, and the volatiles were
removed on a rotary evaporator. The residue was partitioned
between dichloromethane and water in a separatory funnel.
Ammonium chloride was added to assist in phase separation.
The aqueous phase was washed with a fresh portion of
dichloromethane, followed by combining two organic phases,
drying over MgSO4, and filtering. The solvent was removed
on the rotary evaporator, leaving behind the crude product as
an oil. Upon distillation of this oil under vacuum using a 10
cm Vigreaux column, three fractions were collected. The first
fraction contained significant amounts of impurities, while the
other two yielded 4.781 g of clean 1c as a colorless oil (70%);
bp 145-149 °C/4 mm. 1H NMR (CDCl3, 300 MHz): δ 1.62-
1.48 (m, 6H, CH2), 1.40-1.26 (m, 12H, CH2CH2), 0.90 (t, 9H,
3J ) 7.2, CH3). 13C{1H} NMR (CDCl3): δ 28.7 (2J CSn ) 21.6),
3
4
7.29 (m, 1H, H3), 7.16 (dddd, 1H, J HH ) 7.2; 7.2, J HH ) 5J HF
) 1.2, H2), 7.09-6.98 (m, 1H, H4), 1.72-1.46 (m, 6H, CH2CH2-
Sn), 1.38 (qt, 6H, 3J HH ) 7.3, 7.3, CH2CH2CH3), 1.28-1.04 (m,
3
6H, CH2Sn), 0.94 (t, 9H, J HH ) 7.3, CH3). 13C{1H} NMR
(CDCl3): δ 167.3 (1J CF ) 234), 137.3 (3J CF ) 15.6, 2J CSn ) 16.1),
4
130.2 (3J CF ) 7.5, J CSn ) 7.1), 126.9 (2J CF ) 46.3), 124.1 (4J CF
) 3.0, 3J C
) 30.8, 3J C
) 35.8), 114.2 (2J CF ) 28.2, 3J CSn
119
117
Sn
Sn
) 16.3), 29.0 (2J CSn ) 20.1), 27.3 (3J CSn ) 61), 13.7, 9.9 (4J CF
)
1.0, 1J C
) 336, 1J C
) 353). 19F{1H} NMR (CDCl3): δ
119
117
Sn
Sn
-94.0. 119Sn{1H} NMR (CDCl3): δ -37.9 (d, 3J SnF ) 35.7). Anal.
Calcd for C18H31FSn: C, 56.13; H, 8.11. Found: C, 56.06; H,
8.30.
1-(Tr ich lor oger m yl)-2-flu or oben zen e (2d ). GeCl4 (8.42
mmol) and 1d (8.39 mmol) gave 5.04 mmol of 2d (60%) as a
1
colorless liquid after vacuum distillation; bp 78 °C/4 mm. H
3
4
NMR (CDCl3, 400 MHz): δ 7.73 (ddd, 1H, J HH ) 7.2, J HF
)
4
5.6, J HH ) 1.8, H1), 7.69-7.62 (m, 1H, H3), 7.36 (br dd, 1H,
3J HH ) 7.6, 7.6, H2), 7.24 (ddd, 1H, 3J HF ) 8.2, 3J HH ) 8.2, 4J HH
) 1.0, H4). 13C{1H} NMR (CDCl3): δ 164.1 (d, J CF ) 249),
1
3
3
4
135.8 (d, J CF ) 8.1), 133.1 (d, J CF ) 5.5), 125.1 (d, J CF
)
3.0), 121.3 (d, 2J CF ) 25.2), 116.5 (d, 2J CF ) 22.2). 19F{1H} NMR
(CDCl3): δ -99.7. HRMS (EI): calcd for C6H4F35Cl374Ge, m/z
273.8565; obsd, m/z 273.8574.
(2-F lu or op h en yl)ger m a tr a n e (3d ). Triethanolamine (4.83
mmol) and 2d (4.84 mmol) gave 3.67 mmol of 3d (76%) as a
white solid after recrystallization from CH2Cl2-hexanes; mp
219-221 °C. 1H NMR (CDCl3, 400 MHz): δ 7.79 (ddd, 1H, 3J HH
) 7.3, 4J HF ) 5.2, 4J HH ) 2.0, H1), 7.31-7.25 (m, 1H, H3), 7.07
27.1 (3J CSn ) 65), 13.5, 11.4 (1J C
) 343, 1J C
) 358). 19F-
119
117
Sn
Sn
{1H} NMR (CDCl3): δ -94.0 (m, Fm-Sn), -125.3 (m, Fo-Sn).
3
4
119Sn{1H} NMR: δ -18.1 (tt, J SnF ) 12.6, J SnF ) 6.3). Anal.
Calcd for C17H27F4NSn: C, 46.39; H, 6.18; N, 3.18; F, 17.27.
Found: C, 46.65; H, 6.26; N, 3.21; F, 17.57.
3
4
5
(dddd, 1H, J HH ) 7.2, 7.2, J HH ) J HF ) 1.0, H2), 6.99 (ddd,
3
3
4
3
1H, J HH ) J HF ) 8.4, J HH ) 1.0, H4), 3.92 (t, 6H, J ) 5.7,
CH2O), 2.95 (t, 6H, 3J ) 5.7, CH2N). 13C{1H} NMR (CDCl3): δ
1
3
3
1-(Tr ich lor oger m yl)-2,3,5,6-tetr a flu or op yr id in e (2c).
GeCl4 (6.14 mmol) and 1c (6.14 mmol) gave 4.25 mmol of 2c
(69%) as a colorless liquid after vacuum distillation; bp 58-
59 °C/4 mm. 19F{1H} NMR (CDCl3): δ -87.2 (m, Fm-Ge), -129.5
(m, Fo-Ge). HRMS (EI): calcd for C5NF435Cl374Ge, m/z 328.8234;
obsd, m/z 328.8246.
165.4 (d, J CF ) 242), 135.7 (d, J CF ) 10.6), 131.1 (d, J CF
)
2
4
2
8.5), 125.2 (d, J CF ) 31), 123.6 (d, J CF ) 3.0), 115.1 (d, J CF
) 25), 56.9, 51.9. 19F{1H} NMR (CDCl3): δ -99.2 (ddd, 3J FH
)
9.3, 4J FH ) 5.9, 5.9). Anal. Calcd for C12H16O3NFGe: C, 45.92;
H, 5.14; N, 4.46; F, 6.05. Found: C, 46.08; H, 5.22; N, 4.54; F,
6.10.
(2,3,5,6-Tetr a flu or op yr id yl)ger m a tr a n e (3c). Triethan-
olamine (3.50 mmol) and 2c (3.42 mmol) gave 3.02 mmol of
3c (88%) as a white solid after recrystallization from CH2Cl2-
1-(Tr i-n -b u t ylst a n n yl)-3,5-b is(t r iflu or om e t h yl)b e n -
zen e (1e). A 100 mL Schlenk flask equipped with a magnetic
stirbar and a rubber septum was charged under nitrogen with
20 mL of dry ether followed by 4.20 mL of 99% 3,5-bis-
(trifluoromethyl)-1-bromobenzene (24.1 mmol). The resulting
solution was cooled to -78 °C, followed by addition of 10.05
mL of 2.40 M n-BuLi in hexanes (24.1 mmol) within a 15 min
period. The reaction mixture was stirred for 10 min before 6.80
mL of 96% n-Bu3SnCl (24.1 mmol) was added within 6 min.
After the mixture was stirred for 2 h at -78 °C, the flask was
removed from the cold bath and stirring was continued at room
temperature for 16 h. The reaction mixture was transferred
into a 250 mL round-bottom flask using ether, and the volatiles
1
hexanes; mp 182-194 °C dec. H NMR (CDCl3, 300 MHz): δ
3.96 (t, 6H, 3J ) 5.7, CH2O), 3.02 (t, 6H, 3J ) 5.7, CH2N). 13C-
{1H} NMR (CDCl3): δ 57.1, 52.1. 19F{1H} NMR (CDCl3): δ
-93.6 (m, Fm-Ge), -128.1 (m, Fo-Ge). Anal. Calcd for C11H12
-
O3F4N2Ge: C, 35.82; H, 3.28; N, 7.60; F, 20.60. Found: C,
35.91; H, 3.30; N, 7.52; F, 20.75.
1-(Tr i-n -bu tylsta n n yl)-2-flu or oben zen e (1d ). A 100 mL
Schlenk flask equipped with a magnetic stirbar and a rubber
septum was charged under nitrogen with 25 mL of dry ether
followed by 7.00 mL of 2.40 M n-BuLi in hexanes (16.8 mmol).
The resulting solution was cooled to -78 °C. After 15 min
addition of 1.83 mL of 99% 2-fluoro-1-bromobenzene (16.6
mmol) started, which was finished in 10 min. The reaction
mixture was stirred for 15 min before 4.70 mL of 96% n-Bu3-
SnCl (16.6 mmol) was added within 8 min. After 2 h of stirring
at -78 °C the flask was removed from the cold bath and the
stirring was continued at room temperature for 16 h. The
reaction mixture was transferred into a 250 mL round-bottom
flask using ether, and the volatiles were removed on a rotary
evaporator. The residue was partitioned between dichlo-
romethane and water in a separatory funnel. The aqueous
were removed on
a rotary evaporator. The residue was
partitioned between dichloromethane and water in a separa-
tory funnel. The aqueous phase was washed with a fresh
portion of dichloromethane followed by combining two organic
phases, drying over MgSO4, and filtering. The solvent was
removed on the rotary evaporator, leaving behind the crude
product as an oil. Upon distillation of this oil under vacuum
using a 10 cm Vigreaux column, three fractions were collected.
(11) J aura, K. L.; Churamani, L. K.; Sharma, K. K. Indian J . Chem.
1966, 4, 329.

3188 Organometallics, Vol. 23, No. 13, 2004
Kultyshev et al.
2
The first fraction contained significant amounts of impurities,
(CDCl3): δ 143.0, 133.9 (br s), 130.3 (q, J CF ) 33), 123.7 (q,
1J CF ) 273), 122.7 (septet, 3J CF ) 3.9), 56.7, 51.6. 19F{1H} NMR
(CDCl3): δ -62.7. Anal. Calcd for C14H15O3F6NGe: C, 38.94;
H, 3.50; N, 3.24; F, 26.39. Found: C, 39.03; H, 3.51; N, 3.31;
F, 26.53.
while the other two yielded 9.662 g of clean 1e as a colorless
1
oil (80%); bp 138-142 °C/8 mm. H NMR (CDCl3, 300 MHz):
3
δ 7.89 (br s with Sn satellites, 2H, J HSn ) 34, H2, H6), 7.80
(br s, 1H, H4), 1.60-1.51 (m, 6H, CH2CH2Sn), 1.36 (qt, 6H,
3J HH ) 7.3, 7.3, CH2CH2CH3), 1.28-1.04 (m, 6H, CH2Sn), 0.91
(t, 9H, 3J HH ) 7.3, CH3). 13C{1H} NMR (CDCl3): δ 145.8, 135.9
Str u ctu r e Deter m in a tion a n d Refin em en t of 3b . Crys-
tals of 3b were obtained by crystallization from methylene
chloride/ethylcyclohexane. Data were collected on a Nonius
Kappa CCD (Mo KR radiation) and corrected for absorption.
The structure was solved by direct methods and refined on F
for all reflections. Non-hydrogen atoms were refined with
anisotropic displacement parameters. Hydrogen atoms were
included at calculated positions. Crystallographic data collec-
tion and refinement parameters are summarized in Table 3.
3
2
1
(2J CSn ) 28, J CF ) 2.0), 130.3 (q, J CF ) 34), 123.8 (q, J CF
)
273), 121.8 (septet, J CF ) 4.0), 28.9 (2J CSn ) 20.7), 27.2 (3J CSn
3
) 57.9), 13.6, 9.8 (1J C
) 332, 1J C
) 347). 19F{1H} NMR
119
117
Sn
Sn
(CDCl3): δ -63.3. 119Sn{1H} NMR (CDCl3): δ -33.8. Anal.
Calcd for C20H30F6Sn: C, 47.74; H, 6.01. Found: C, 47.61; H,
6.11.
1-(Tr ich lor oger m yl)-3,5-bis(t r iflu or om et h yl)ben zen e
(2e). GeCl4 (7.89 mmol) and 1e (7.89 mmol) gave 5.52 mmol
of 2e (70%) as a colorless liquid after vacuum distillation, bp
63 °C/3 mm. 1H NMR (CDCl3, 300 MHz): δ 8.20 (br s, 2H, H2,
H6), 8.14 (br s, 1H, H4). 13C{1H} NMR (CDCl3): δ 137.4, 132.9
Ack n ow led gm en t. Support of our work at USC by
the Loker Hydrocarbon Research Institute is gratefully
acknowledged.
2
3
(q, J CF ) 34), 131.7 (br s), 126.8 (septet, J CF ) 4), 122.6 (q,
1J CF ) 274). 19F{1H} NMR (CDCl3): δ -63.1. HRMS (EI): calcd
for C8H3F635Cl374Ge, m/z 391.8416; obsd, m/z 391.8402.
(3,5-Bis(tr iflu or om eth yl)p h en yl)ger m a tr a n e (3e). Tri-
ethanolamine (3.97 mmol) and 2e (3.90 mmol) gave 3.48 mmol
of 3e (89%) as a white solid after recrystallization from CH2-
Cl2-hexanes; mp 192-204 °C dec. 1H NMR (CDCl3, 300
MHz): δ 8.20 (br s, 2H, H2, H6), 7.80 (br s, 1H, H4), 3.91 (t,
Su p p or tin g In for m a tion Ava ila ble: Text giving NMR
spectroscopic data for n-BuGeCl3 and synthetic procedures for
germatranes 3a -e, tables giving crystallographic data for 3a
and 3b, and an ORTEP drawing of 3a . This material is
available free of charge via the Internet at http://pubs.acs.org.
3
3
6H, J ) 5.7, CH2O), 2.96 (t, J ) 5.7, CH2N). 13C{1H} NMR
OM0400189