Synthesis of ansa-zirconocenes based on 2-(phenylethynyl)-1H-indene. the crystal and molecular structure of the complex [μ-CH2CH 2(η5-2-PhC≡CInd)2]ZrCl2 (Ind is inden-1-yl)

Article abstract of DOI:10.1007/s11172-007-0012-5

Alkynyl-substituted indene was first used as a ligand for the synthesis of transition metal complexes. ansa-Zirconocenes containing ethylene and dimethylsilylene bridges were synthesized starting from 2-(phenylethynyl)-1H- indene. The structure of the for

Full text of DOI:10.1007/s11172-007-0012-5

Russian Chemical Bulletin, International Edition, Vol. 56, No. 1, pp. 70—76, January, 2007
70
Synthesis of ansaꢀzirconocenes based on 2ꢀ(phenylethynyl)ꢀ1Hꢀindene.
The crystal and molecular structure of the complex
[µꢀCH2CH2(η5ꢀ2ꢀPhC≡CInd)2]ZrCl2 (Ind is indenꢀ1ꢀyl)
P. V. Ivchenko,aꢀ I. E. Nifant´ev,a and Sh. G. Mkoyanb
aDepartment of Chemistry, M. V. Lomonosov Moscow State University,
1 Leninskie Gory, 119992 Moscow, Russian Federation.
Fax: +7 (495) 939 4523. Eꢀmail: inpv@org.chem.msu.ru
bInstitute of Problems of Chemical Physics, Russian Academy of Sciences,
1 prosp. Akad. Semenova, 142432 Chernogolovka, Moscow Region, Russian Federation
Alkynylꢀsubstituted indene was first used as a ligand for the synthesis of transition metal
complexes. ansaꢀZirconocenes containing ethylene and dimethylsilylene bridges were syntheꢀ
sized starting from 2ꢀ(phenylethynyl)ꢀ1Hꢀindene. The structure of the former compound was
established by Xꢀray diffraction.
Key words: indanꢀ2ꢀone, 2ꢀ(phenylethynyl)ꢀ1Hꢀindene, ansaꢀzirconocenes, Xꢀray diffracꢀ
tion study.
For more than 20 years, starting from the pioneering
larly true for alkynylindenes. The only known representaꢀ
tive of this group of compounds, 3ꢀethynylꢀ1Hꢀindene
(3), is unstable and its chemical properties are virtually
unknown.6 In addition, compound 3 contains the acidic
hydrogen atom at the terminal triple bond (Scheme 1)
and, consequently, it can hardly be used for the synthesis
of metallocenes.
studies,1—3 bisꢀindenyl ansaꢀcomplexes of Group IV eleꢀ
ments, predominantly, zirconium(IV) complexes 1, have
been considered as one of the most promising classes of
catalysts for alkene polymerization.4,5 Hundreds of new
bisꢀindenyl ansaꢀzirconocenes have been synthesized, and
the relationship between the structure of metallocenes
and their catalytic properties has been established. It was
found that compounds containing short bridges, such as
CR2, CR2CR2, or SiR2, have high activity. Symmetric
ansaꢀcomplexes exist as mixtures of two diastereomeric
forms of 2, viz., the rac form, which has C2 symmetry and
catalyzes isotactic αꢀolefin polymerization, and the
meso form, which has Cs symmetry and catalyzes atactic
polymerization. Hence, isolation of pure rac forms is one
of problems associated with the synthesis of metallocenes
as potential polymerization catalysts.
Scheme 1
B– is a base
Z = CR2, CR2CR2, SiR2
In our opinion, metallocenes based on alkynylindenes
are of interest both from the point of view of the influence
of the substituent on the properties of the complex and as
the starting compounds for further transformations into
In spite of the fact that numerous indenes have been
synthesized and transformed into metallocenes, some of
these compounds remain poorly studied. This is particuꢀ
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 68—73, January, 2007.
1066ꢀ5285/07/5601ꢀ0070 © 2007 Springer Science+Business Media, Inc.

ansaꢀZirconocenes from 2ꢀ(phenylethynyl)indene
Russ.Chem.Bull., Int.Ed., Vol. 56, No. 1, January, 2007
71
more complicated, including supramolecular, structures.
Due to the presence of the reactive triple bond, metalloꢀ
cenes can be considered as potential substrates in reacꢀ
tions with nucleophilic reagents and dienes. In the present
study, we synthesized 2ꢀ(phenylethynyl)ꢀ1Hꢀindene (4)
and used it for the preparation of ansaꢀzirconoꢀ
cenes 5 and 6.
Synthesis of bisꢀindenyl bridged compounds. We chose
bis(2ꢀphenylethynyl)indenyl compounds with CH2CH2
and SiMe2 bridges as potential ligands for the synthesis of
ansaꢀzirconocenes.
An attempt to synthesize the first of these compounds,
viz., 2ꢀ(phenylethynyl)ꢀ3ꢀ{2ꢀ[2ꢀ(2ꢀphenylethynyl)ꢀ1Hꢀ
indenꢀ3ꢀyl]ethyl}ꢀ1Hꢀindene (7), according to a known
procedure8 (by the reaction of the lithium derivative of
compound 4 with 1,2ꢀdibromoethane in THF) failed. An
analysis of the reaction mixture demonstrated that the
yield of the target compound was no higher than 15%,
and the mixture contained substantial amounts of
1ꢀ(2ꢀbromoethyl)ꢀ1Hꢀindene 8 and spiro derivative 9
(Scheme 3). In diethyl ether, the reaction proceeded very
slowly. A satisfactory yield of compound 7 was achieved
in the reaction in diethyl ether in the presence of catalytic
amounts of CuNCS, which has recently found use as an
efficient catalyst for the reaction of indenyllithium with
chlorosilanes.9 Therefore, we demonstrated that copper
salts can catalyze not only silylation but also alkylation of
indenes.
Evidently, the reaction of the lithium derivative of
indene 4 with dibromoethane produces a mixture of bisꢀ
indenyl compounds isomeric on double bond location in
the indenyl ring, which is confirmed by the appearance of
signals at δ 1.3—1.4 (—CH2CH2CH<) and the presence
of signals for the vinyl protons of the fiveꢀmembered
ring. To simplify the isolation of the product, this mixꢀ
ture was treated with two equivalents of nꢀbutyllithium
followed by hydrolysis. The resulting most stable isoꢀ
mer 7 was isolated by crystallization in 31% yield (see
Scheme 3).
We chose the phenylethynyl substituent for the indene
molecule because phenylacetylenes are more stable than
alkylacetylenes.
Results and Discussion
Synthesis of 2ꢀ(phenylethynyl)ꢀ1Hꢀindene (4). We synꢀ
thesized indene 4 by the reaction of PhC≡CMgBr with
indanꢀ2ꢀone followed by hydrolysis and acidꢀcatalyzed
dehydration of intermediate alcohol (Scheme 2).
The reaction of two equivalents of the lithium derivaꢀ
tive of indene 4 with SiMe2Cl2 (in particular, in the presꢀ
ence of CuNCS as the catalyst) produced dimethyl{bis[2ꢀ
(phenylethynyl)ꢀ1Hꢀindenꢀ1ꢀyl]}silane (10) in satisfacꢀ
tory yield (>70%). However, we failed to isolate product
10 in pure form, because is does not crystallize and is
insufficiently stable for preparative column chromatoꢀ
graphy.
Scheme 2
It appeared that, unlike usual Grignard reagents, which
cause deprotonation of indanꢀ2ꢀones,7 the PhC≡CMgBr
reagent rather smoothly adds to the C=O bond to give,
after dehydration, compound 4 in 67% yield. Unlike
ethynylindene 3, compound 4 is thermally stable and can
easily be purified by recrystallization.
Indenes can be used as ligands for the synthesis of
complexes of Group IV elements mainly due to their abilꢀ
ity to form rather stable alkali metal derivatives, which
can be subjected to further transformations. Compound 4
reacts in diethyl ether with a solution of nꢀbutyllithium to
form a precipitate of its lithium derivative, which remains
unchanged in appearance on storage. The lithium derivaꢀ
tive of indene 4 was not isolated and was used in situ in the
subsequent steps of the synthesis of bisꢀindenyl bridged
compounds.
Hence, we decided to perform the synthesis of comꢀ
pound 10 in two steps. First, (dimethyl)chloro[2ꢀ(phenylꢀ
ethynyl)ꢀ1Hꢀindenꢀ1ꢀyl]silane (11) was prepared in 97%
yield by the reaction of the lithium derivative of indene 4
with excess SiMe2Cl2 in the absence of a catalyst. Then
the reaction of silane 11 with the lithium derivative of
indene 4 was performed in the presence of CuNCS
1
(Scheme 4). The H NMR spectroscopic study demonꢀ
strated that the reaction mixture contained virtually pure
bisꢀindenyl compound 10, which made it possible to use
this mixture after minimal purification (from inorganic
impurities).
Synthesis of ansaꢀzirconocenes. As a rule, ansaꢀzirꢀ
conocenes are prepared by the reaction of dilithium deꢀ
rivatives of the corresponding bisꢀindenyl compounds

72
Russ.Chem.Bull., Int.Ed., Vol. 56, No. 1, January, 2007
Ivchenko et al.
Scheme 3
Scheme 4
mic form of 5 was isolated by recrystallization from
dimethoxyethane in 68% yield (Scheme 5).
Scheme 5
Compound 6 was synthesized according to a convenꢀ
tional procedure by the reaction of dilithium derivative 10
with ZrCl4 (Scheme 6). After recrystallization from
dimethoxyethane, the yield of racꢀ6 was 34%.
with ZrCl4. The reaction can be performed in various
solvents (most commonly, in diethyl ether or THF).
The reaction of the dilithium derivative of compound 7
with ZrCl4 both in diethyl ether and THF produces the
target compound, viz., ansaꢀzirconocene 5, in very low
yield (1H NMR spectroscopic data for the reaction mixꢀ
ture). One of the possible ways of increasing the yield of
ansaꢀzirconocenes is based on the use of distannylated
derivatives of bisꢀindenyl compounds instead of dilithium
derivatives.10 We synthesized bis(triethylstannyl) derivaꢀ
tive 12 in quantitative yield (NMR spectroscopic data for
the reaction mixture) and used it for the synthesis of
zirconocene 5 without additional purification. The reacꢀ
tion was performed in dichloromethane. The pure raceꢀ
Scheme 6
The structures of compounds 5 and 6 were established
by NMR spectroscopy. The conclusion that compound 6
exists in the rac rather than in the meso form was
1
made based on the analysis of the H and 13C NMR

ansaꢀZirconocenes from 2ꢀ(phenylethynyl)indene
Russ.Chem.Bull., Int.Ed., Vol. 56, No. 1, January, 2007
73
C(6)
C(5)
C(13)
C(7)
C(1)
C(8)
C(14)
C(10)
C(12)
C(11)
C(4)
C(3)
C(9)
C(2)
C(15)
C(18)
Zr
C(17)
Cl(1)
Cl(2)
C(16)
C(19)
C(28)
C(32)
C(21)
C(22)
C(30)
C(33)
C(34)
C(35)
C(20)
C(23)
C(24)
C(29)
C(27)
C(31)
C(36)
C(26)
C(25)
Fig. 1. Molecular structure of compound 5.
spectra, which show one signal of the Me groups of the
—SiMe2— bridge. It is impossible to assign compound 5
containing the dimethylene bridge to the rac or meso form
based only on the NMR spectroscopic data. Hence,
we established the structure of compound 5 by Xꢀray difꢀ
fraction.
Xꢀray diffraction study of compound 5. Single crystals
of compound 5 were grown by diffusion crystallization
from a CH2Cl2—diethyl ether mixture, and compound 5
was studied by Xꢀray diffraction, which confirmed that
molecule 5 exists as the rac isomer (Fig. 1).
The bond lengths and bond angles in molecule 5 are
given in Table 1.
In the molecule of ansaꢀcomplex 5, the zirconium
atom is η5ꢀcoordinated by the indenyl fragment and two
chlorine atoms. The molecule has distortions characterisꢀ
tic of ansaꢀmetallocenes due to the presence of the short
bridge between two indenyl fragments. The C(1)—C(18)
and C(19)—C(20) bonds deviate from the planes of the
indenyl rings, whereas no noticeable deviations of the
bond lengths and bond angles from the expected values
were found. The indenyl ring and the phenyl ring of the
2ꢀPhC≡C fragment are noncoplanar. The C≡C bond
lengths (1.186 and 1.200 Å) are typical of acetylene and
substituted acetylenes. The C(sp2)—C(sp)—C(sp) bond
angles (173.8—177.7°) are close to theoretical values.
The structure of the bisꢀindenyl ansaꢀzirconocene fragꢀ
ment in molecule 5 is similar to those in molecules of
other ethyleneꢀbridged bisꢀindenyl complexes, 13 (see
Ref. 8) and, particularly, 14.11 In the latter compound,
the Zr—Cl and Zr—C bond lengths and the geometry of
the bridging fragment are virtually identical.
Table 1. Bond lengths (d) and bond angles (ω) in molecule 5
Bond
d/Å
Bond
d/Å
Angle
ω/deg
Zr—Cl(2)
Zr—Cl(1)
Zr—C(1)
2.4046(9)
2.4236(8)
2.485(3)
2.499(3)
2.498(3)
2.508(3)
2.541(3)
2.547(3)
2.561(2)
2.596(3)
2.623(3)
2.657(3)
1.434(4)
1.186(4)
1.439(4)
C(1)—C(18)
C(18)—C(19)
C(19)—C(20)
C(28)—C(29)
C(29)—C(30)
C(30)—C(31)
Zr—CCp(1)
Zr—CCp(2)
Zr—Cp(1)centr
Zr—Cp(2)centr
1.494(4)
1.533(4)
1.504(4)
1.424(4)
1.200(4)
1.433(4)
2.542(3)
2.5612(3)
2.235(3)
2.258(3)
C(11)—C(10)—C(9)
C(10)—C(11)—C(12)
C(1)—C(18)—C(19)
C(20)—C(19)—C(18)
C(30)—C(29)—C(28)
C(29)—C(30)—C(31)
С—С—ССр(1)
177.7(3)
176.4(3)
111.4(2)
111.2(2)
173.8(3)
Zr—C(9)
Zr—C(20)
Zr—C(28)
Zr—C(8)
Zr—C(27)
Zr—C(2)
Zr—C(21)
Zr—C(7)
Zr—C(26)
C(9)—C(10)
C(10)—C(11)
C(11)—C(12)
177.6(3)
106.2(2)—109.4(2)
106.6(2)—108.8(3)
99.48(4)
С—С—ССр(2)
Cl(2)—Zr—Cl(1)
Cl(1)—Zr—Cp(1)centr
Cl(2)—Zr—Cp(1)centr
Cl(1)—Zr—Cp(2)centr
Cl(2)—Zr—Cp(2)centr
Ср(1)centr—Zr—Ср(2)centr
Ср(1)—Ср(2)
107.0(7)
107.3(7)
107.3(6)
106.0(7)
126.5(2)
58.6(2)
Note. Cp(1) and Cp(2) are the cyclopentadienyl fragments C(1)C(2)C(7)C(8)C(9) and C(20)C(21)C(26)C(27)C(28),
respectively; Cр(1)centr and Cр(2)centr are the centroids of these fragments.

74
Russ.Chem.Bull., Int.Ed., Vol. 56, No. 1, January, 2007
Ivchenko et al.
2ꢀ(Phenylethynyl)ꢀ3ꢀ{2ꢀ[2ꢀ(2ꢀphenylethynyl)ꢀ1Hꢀindenꢀ3ꢀ
yl]ethyl}ꢀ1Hꢀindene (7). A BuLi solution (20.6 mL, 33 mmol)
was added to a suspension of indene 4 (6.49 g, 30 mmol) in
diethyl ether (80 mL) with cooling to –40 °C for 5 min. The
slightly turbid reaction mixture was allowed to warm to ~20 °C,
stirred for 2 h, and cooled to –40 °C. Then CuNCS (0.36 g,
3 mmol) was added. The reaction mixture turned slightly red.
After 5 min, a solution of 1,2ꢀdibromoethane (1.3 mL, 15 mmol)
in diethyl ether (10 mL) was rapidly added, cooling being mainꢀ
tained. The reaction mixture was stirred with cooling for 1 h,
allowed to warm to ~20 °C, stored for 16 h, and cooled to
–20 °C. Then BuLi (22 mL) was added. The reaction mixture
was allowed to warm to ~20 °C and stirred for 1 h. Then a 10%
aqueous NH4Cl solution (100 mL) and CH2Cl2 (300 mL) were
gradually added with cooling. The organic phase was separated,
washed with water to neutral pH, and dried over MgSO4. The
solvents were removed under reduced pressure, and the residue
was recrystallized from diethyl ether (100 mL). The colorless
finely crystalline powder that precipitated was filtered off and
dried in vacuo. Product 7 was obtained in a yield of 2.12 g (31%).
Found (%): C, 94.34; H, 5.66. C36H26. Calculated (%): C, 94.29;
Therefore, the possibility of synthesizing early transiꢀ
tion metal complexes containing the alkynyl substituent
in the indenyl ring was exemplified by the synthesis of two
simplest bisꢀindenyl ansaꢀzirconocenes with short bridges.
Experimental
All experiments were performed under argon. The lithium
derivatives and zirconium complexes were synthesized in allꢀ
sealed Schlenkꢀtype glassware. Ethereal solvents were distilled
from sodium benzophenone ketyl. Dichloromethane was puriꢀ
fied by distillation over CaH2. Indanꢀ2ꢀone (Acros) was used
without prepurification. Phenylacetylene (Acros) was distilled
under reduced pressure before use. The 1H and 13C NMR specꢀ
tra were recorded on a Varian VXRꢀ400 instrument. Elemental
analysis was carried out on a CarloꢀErba analyzer.
1
H, 5.71. H NMR (CDCl3, 20 °C), δ: 3.18 and 3.56 (both s,
4 H each, —CH2—); 7.18—7.35 (group of m, 14 H, H arom.);
7.40 (d, 2 H, H arom., 3J = 7.8 Hz); 7.56 (d, 2 H, H arom., 3J =
7.6 Hz). 13C NMR (CDCl3, 20 °C), δ: 26.1, 41.5 (—CH2—);
86.2, 96.1 (—C≡); 119.4, 123.6, 126.4, 127.8, 128.1, 131.3,
125.6 (—CH=); 123.4, 123.6, 142.9, 144.4, 149.5 (>C=).
The reaction in THF afforded a complex mixture of prodꢀ
1
2ꢀ(Phenylethynyl)ꢀ1Hꢀindene (4). An EtBr solution (44.7 mL,
0.6 mol) in Et2O (600 mL) was added to Mg chips (14.6 g,
0.6 mol) in Et2O (20 mL) at such a rate that steady reflux of the
reaction mixture was maintained. The reaction mixture was
stirred for 1 h. Then a solution of phenylacetylene (68.1 mL,
0.62 mol) in Et2O (200 mL) was added at ~20 °C for 30 min. The
reaction mixture was stirred at ~20 °C for 1 h and then under
reflux for 2 h followed by cooling to 0 °C. A solution of indanꢀ2ꢀ
one (52.9 g, 0.4 mol) in diethyl ether (200 mL) was added for
10 min. The mixture was allowed to warm to ~20 °C. After 16 h,
a 10% aqueous NH4Cl solution was added until the precipitate
was completely dissolved. The organic phase was separated, and
the aqueous phase was extracted with Et2O (4×100 mL). The
combined organic phases were dried over MgSO4, and the solꢀ
vent was removed under reduced pressure (10 Torr) at 80 °C; the
major portion of phenylacetylene was distilled off. The residue
was dissolved in benzene (200 mL). Then pꢀtoluenesulfonic acid
(0.5 g) and ethanol (2 mL) were added, and the reaction mixture
was refluxed using a Dean—Stark trap until elimination of water
ceased (1.5 h). The resulting redꢀbrown solution was cooled,
washed with water, a Na2CO3 solution, and water to neutral pH,
and dried over MgSO4. The solvent was removed under reꢀ
duced pressure, and the residue was recrystallized from hexane
(100 mL). The precipitate that formed was filtered off, washed
with cold diethyl ether (50 mL), and dried in vacuo. The product
was obtained in a yield of 58.0 g (67.4%) as a finely crystalline
paleꢀyellow powder. Found (%): C, 94.37; H, 5.63. C17H12.
Calculated (%): C, 94.41; H, 5.59. 1H NMR (CDCl3, 20 °C), δ:
3.68 (br.s, 2 H, —CH2—); 7.22 (br.s, 1 H), 7.28—7.50 (group
of m, 7 H), 7.58 (m, 2 H) (H arom., —CH=). 13C NMR (CDCl3,
20 °C), δ: 42.6 (—CH2—); 86.6, 94.0 (—C≡); 121.3, 123.4,
125.6, 126.6, 128.1, 128.2, 131.4, 137.2 (—CH=); 123.2, 127.2,
142.8, 144.0 (>C=).
ucts. The H NMR spectrum of the mixture shows signals of
compound 7 and the isomeric bisꢀindenyl compounds, as well as
characteristic signals of compounds 8 (δ 2.57 and 3.44, both m,
CH2CH2Br) and 9 (δ 1.72 and 1.93, both m, CH2CH2). After
distillation at 140—150 °C (0.5 Torr), the fraction containing
virtually pure compound 9 and an insignificant impurity of inꢀ
dene 4 was distilled off.
1
Compound 9. H NMR (CDCl3, 20 °C), δ: 1.72 and 1.93
(both m, 2 H each, —CH2— of the cyclopropane ring); 7.27
(br.s, 1 H, =CH— of the fiveꢀmembered ring); 7.07—7.63
(group of m, 9 H, —CH=). 13C NMR (CDCl3, 20 °C), δ: 15.5
(—CH2—); 34.6 (>C<); 83.3, 95.8 (—C≡); 117.6, 121.8, 125.1,
125.8, 128.2, 131.3, 131.4, 132.7 (—CH=); 123.0, 132.4, 137.2,
147.6 (>C=).
(Dimethyl)chloro[2ꢀ(phenylethynyl)ꢀ1Hꢀindenꢀ1ꢀyl]silane
(11). A BuLi solution (15 mL, 24 mmol) was added to a suspenꢀ
sion of indene 4 (4.32 g, 20 mmol) in diethyl ether (70 mL) with
cooling to –40 °C for 5 min. The slightly turbid reaction mixture
was allowed to warm to ~20 °C and stirred for 2 h. Then the
reaction mixture was cooled to –40 °C, and SiMe2Cl2 (3.6 mL,
30 mmol) was added. The reaction mixture was stirred with
cooling for 1 h, allowed to warm to ~20 °C, stored for 16 h, and
filtered. The filtrate was concentrated under reduced pressure.
The residue (a paleꢀyellow oil) was dried in vacuo. The yield of
product 11 was 5.98 g (97%). Found (%): C, 73.99; H, 5.65.
C19H17ClSi. Calculated (%): C, 73.88; H, 5.55. 1H NMR
(CDCl3, 20 °C), δ: 0.20 and 0.82 (both s, 3 H each, Me); 4.00 (s,
1 H, —CH<); 7.37—7.47 (group of m, 6 H), 7.57 (br.d, 1 H,
3J = 7.2 Hz), 7.64 (m, 2 H), 7.78 (br.d, 1 H, 3J = 7.2 Hz)
(H arom., —CH=). 13C NMR (CDCl3, 20 °C), δ: 1.67, 1.87
(Me); 49.8 (—CH<); 87.0, 95.4 (—C≡); 121.4, 123.7, 125.3,
126.1, 128.2, 128.3, 131.1, 136.6 (—CH=); 123.1, 126.6, 143.0,
143.3 (>C=).

ansaꢀZirconocenes from 2ꢀ(phenylethynyl)indene
Russ.Chem.Bull., Int.Ed., Vol. 56, No. 1, January, 2007
75
Dimethyl{bis[2ꢀ(phenylethynyl)ꢀ1Hꢀindenꢀ1ꢀyl]}silane (10).
A BuLi solution (12.5 mL, 20 mmol) was added to a suspension
of indene 4 (4.11 g, 19 mmol) in diethyl ether (80 mL) with
cooling to –40 °C for 5 min. The reaction mixture was allowed
to warm to ~20 °C, stirred for 2 h, and cooled to –40 °C. Then
CuNCS (0.24 g, 2 mmol) was added. After 5 min, a solution of
silane 11 (5.87 g, 19 mmol) in diethyl ether (20 mL) was added
for 10 min, cooling being maintained. The reaction mixture was
stirred with cooling for 1 h. Then the mixture was allowed
to warm to ~20 °C, stirred for 16 h, and cooled to 0 °C.
A 10% aqueous NH4Cl solution (20 mL) was added. The orꢀ
ganic phase was separated, washed with water to neutral pH,
and dried over MgSO4. The solvent was removed under reduced
pressure, and the residue was dried in vacuo. The reaction prodꢀ
uct (9.3 g, a darkꢀyellow viscous oil) contained a mixture of rac
and meso diastereomers and was virtually free of impurities of
indene 4. The product was used without additional purification.
Found (%): C, 88.65; H, 5.88. C36H28Si. Calculated (%):
Table 2. Principal crystallographic data for compound 5
Parameter
Characteristic
Molecular formula
Molecular weight
C
36H24Cl2Zr
618.67
Crystal dimension/mm
Crystal system
Space group
0.2×0.2×0.2
Monoclinic
P21/n
a/Å
b/Å
c/Å
α/deg
16.814(3)
17.702(4)
9.258(2)
90
β/deg
94.42(3)
90
3275.3(11)
8
1.291
0.075
γ/deg
V/Å3
Z
dcalc/g cm–3
µ/mm–1
1
C, 88.48; H, 5.78. H NMR (CDCl3, 20 °C), δ: –0.29, –0.21,
Number of reflections
Number of independent reflections
Rint
4444
4023
0.0217
and –0.08 (all s, 6 H, Me); 4.52 and 4.76 (both s, 2 H, —CH<);
7.20—7.72 (group of m, 20 H, H arom., —CH=).
5
µꢀ{Bis[η ꢀ2ꢀ(phenylethynyl)ꢀ1Hꢀindenꢀ1ꢀyl]ꢀ1,2ꢀethaneꢀ
Extinction coefficient
R1, wR2 based on reflections
with F > 2σ(F )
0.0018(4)
0.0257, 0.0723
diyl}dichlorozirconium(IV) (5). A BuLi solution (2 mL, 3.2 mmol)
was added with stirring and cooling to –20 °C to a solution of
compound 7 (0.50 G, 1.09 mmol) in diethyl ether (40 mL),
which gave rise to a lemonꢀyellow dilithium derivative. The
reaction mixture was allowed to warm to ~20 °C, stirred for
1.5 h, and cooled to –40 °C. Then Et3SnCl (0.54 mL, a minimal
excess with respect to BuLi) was added. The resulting paleꢀ
yellow solution of compound 12 was separated from LiCl by
decantation, the solvent was removed, and a small amount was
taken for NMR spectroscopy. Then CH2Cl2 (40 mL) was added,
the mixture was cooled to –20 °C, and ZrCl4 (0.254 g, 1.1 mmol)
was added with vigorous stirring. The reaction mixture was stirred
for 1 h without cooling and kept for ~14 h. The solution was
separated by decantation, and the precipitate was washed with
small portions of CH2Cl2. The solvent was removed (the residue
fully crystallized out), and diethyl ether (20 mL) was added. The
precipitate was washed with diethyl ether (4×10 mL), recrystalꢀ
lized from dimethoxyethane, and dried in vacuo. The yield of the
R1, wR2 based on all reflections
0.0622, 0.0887
40 mmol) was added to a solution of compound 10 (9.4 g,
19.23 mmol) in diethyl ether (80 mL) with cooling to –20 °C.
The mixture was allowed to warm to ~20 °C, stirred for 16 h,
and cooled to –40 °C. Then ZrCl4 (4.48 g, 19.23 mmol) was
added, after which a yellowꢀorange precipitate was immediately
formed. The reaction mixture was allowed to warm to ~20 °C
and stirred for 16 h. The precipitate was separated by filtration,
recrystallized from dimethoxyethane, and dried in vacuo. The
yield of the rac form of 6 was 2.12 g (34%). 1H NMR (CD2Cl2,
3
3
20 °C), δ: 1.52 (s, 6 H, Me); 6.70 (dd, 2 H, J = 8.9 Hz, J =
6.7 Hz), 7.09 (s, 2 H), 7.35 (dd, 2 H, 3J = 8.9 Hz, 3J = 6.7 Hz),
3
7.45 and 7.52 (both m, 6 H each), 7.76 (d, 2 H, J = 8.9 Hz)
1
rac form of 5 was 210 mg (68%). H NMR (CD2Cl2, 20 °C), δ:
(all H arom.). 13C NMR (CD2Cl2, 20 °C), δ: 0.75 (Me); 86.3,
88.5 (—C≡); 96.8, 115.6, 122.9, 127.0, 133.6 (>C=); 122.7,
125.4, 126.2, 127.7, 129.0, 128.5, 129.5, 131.6 (—CH=).
Xꢀray diffraction study of compound 5. The unit cell paꢀ
rameters and the Xꢀray diffraction set were measured on
an automated fourꢀcircle KMꢀ4 diffractometer (KUMA
DIFFRACTION) at 293.0(2) K (MoꢀKα radiation, λ =
0.71073 Å, ωꢀscanning technique). The structure was solved by
direct methods and refined by the fullꢀmatrix leastꢀsquares
method against F 2. The hydrogen atoms were located from a
difference Fourier map and refined isotropically. The bond
lengths and bond angles in molecule 5 are given in Table 1. The
Xꢀray data collection and refinement statistics are listed in
Table 2.
4.10 (AA´BB´ system, 4 H, —CH2CH2—); 6.73 (s, 2 H,
3
3
H arom.); 6.90 (dd, 2 H, H arom., J = 9.2 Hz, J = 7.2 Hz);
7.31 (dd, 2 H, H arom., 3J = 8.4 Hz, 3J = 7.2 Hz); 7.82 (d, 2 H,
H arom., 3J = 9.2 Hz); 7.42 (d, 2 H, H arom., 3J = 8.4 Hz); 7.47
(m, 6 H, H arom.); 7.61 (m, 4 H, H arom.). 13C NMR (CD2Cl2,
20 °C), δ: 28.9 (—CH2—); 83.6, 97.6 (—C≡); 112.4, 122.7,
123.0, 130.2 (>C=); 114.4, 124.0, 125.3, 126.2, 127.7, 129.0,
129.5, 131.9 (—CH=).
The 1H NMR spectrum of intermediate compound 12 (benꢀ
zeneꢀd6, 20 °C, δ): 0.97 (m, 12 H, Sn—CH2—); 1.18 (m, 18 H,
Sn—CH2CH3); 3.62—3.76 (group of m, —CH2CH2—); 4.32
and 4.33 (both s, 2 H, >CH—); 7.10—8.10 (group of m, 18 H,
H arom.). 13C NMR (benzeneꢀd6, 20 °C), δ: 1.8 (Sn—C); 8.4
(—CH2CH2—); 10.0 (>CH—); 11.1 (Sn—CH2CH3); 28.1, 28.2,
29.6, 30.2 (>C= of the fiveꢀmembered ring); 87.7, 87.8, 96.6,
96.7 (—C≡); 120.3, 120.4, 122.0, 122.1, 124.6, 124.8, 128.6,
128.7, 131.5, 131.6 (—CH=); 111.8, 144.2, 144.3, 146.8,
146.9 (>C=).
References
5
µꢀ{Bis[η ꢀ2ꢀ(phenylethynyl)ꢀ1Hꢀindenꢀ1ꢀyl]dimethylsilaneꢀ
1. J. Ewen, J. Am. Chem. Soc., 1984, 106, 6355.
diyl}dichlorozirconium(IV) (6). A 1.6 M BuLi solution (25 mL,
2. US Pat. 4,522,982; Chem. Abstrs, 1985, 103, P124098c.

76
Russ.Chem.Bull., Int.Ed., Vol. 56, No. 1, January, 2007
Ivchenko et al.
3. W. Kaminsky, K. Kulper, H. Brintzinger, and F. Wild, Angew.
Chem., Int. Ed. Engl., 1985, 24, 507.
4. H. H. Brintzinger, D. Fischer, R. Mulhaupt, B. Rieger, and
R. M. Waymouth, Angew. Chem., Int. Ed. Engl., 1995,
34, 1143.
5. L. Resconi, L. Cavallo, A. Fait, and F. Piemontesi, Chem.
Rev., 2000, 100, 1253.
6. A. Padwa, D. J. Austin, Y. Gareau, J. M. Kassir, and S. L.
Xu, J. Am. Chem. Soc., 1993, 115, 2637.
8. F. Piemontesi, I. Gamurati, L. Resconi, D. Balboni,
A. Sironi, M. Moret, R. Ziegler, and N. Piccolrovazzi, Orꢀ
ganometallics, 1995, 14, 1256.
9. Eur. Pat. Appl. EP 617,044; Chem. Abstrs, 1995, 122, 10262p.
10. I. E. Nifant´ev and P. V. Ivchenko, Organometallics, 1997,
16, 713.
11. R. Leino, H. J. G. Luttikhedde, A. Lehtonen, P. Ekholm,
and J. H. Nasman, J. Organomet. Chem., 1998, 558, 181.
7. H. Morrison and D. Giacherio, J. Org. Chem., 1982,
47, 1058.W
Received May 23, 2006;
in revised form October 18, 2006