Novel nine-membered titanaheterocycles - Structure, ab initio calculations, and preparative use towards the selective synthesis of substituted cyclopentanols

Article abstract of DOI:10.1002/(SICI)1099-0682(199809)1998:9<1253::AID-EJIC1253>3.0.CO;2-H

Reactions of Cp₂Ti(CO)₂ (3) with two equivalents of α,β-unsaturated ketones 4 yield the novel titana-2,9-dioxacyclonona-3,7-dienes 5. Cross-coupling of 3 with two different ketones 4 and 6 to give 7 can be achieved under certain reaction conditions. Hydrolysis of 5 or 7 may generate diketones 9, cyclopentanols 10/11, or cyclopentenes 12/13, depending on substituents and conditions. The X-ray crystal structure of 5a, the first nine-membered bis(η⁵-cyclopentadienyl)-substituted titanaheterocycle containing carbon, is presented. Ab initio calculations were performed for 5a and for titana-2-oxacyclopentene 1, a conceivable intermediate in the coupling reaction.

Full text of DOI:10.1002/(SICI)1099-0682(199809)1998:9<1253::AID-EJIC1253>3.0.CO;2-H

FULL PAPER
Novel Nine-Membered Titanaheterocycles – Structure, ab initio Calculations,
and Preparative Use towards the Selective Synthesis of Substituted
Cyclopentanols
a
b
a
a
a
Frank Hampel , Nico van Eikema Hommes* , Sven Hoops , Faramarz Maaref , and Rainer Schobert*
Institut für Organische Chemie der Universität Erlangen-Nürnberga,
Henkestr. 42, D-91054 Erlangen, Germany
Fax: (internat.) ϩ 49(0)9131/856864
E-mail: schobert@organik.uni-erlangen.de
Computer-Chemie-Centrum der Universität Erlangen-Nürnbergb,
Nägelsbachstr. 25, D-91052 Erlangen, Germany
Fax: (internat.) ϩ 49(0)9131/856566
E-mail: hommes@ccc.uni-erlangen.de
Received March 24, 1998
Keywords: Cyclizations / Cross-coupling / Ab initio calculations / Titanium / Metallacycles
Reactions of Cp
unsaturated ketones
2
Ti(CO)
2
(3) with two equivalents of α,β-
yield the novel titana-2,9-
depending on substituents and conditions. The X-ray crystal
structure of 5a, the first nine-membered bis(η -
5
4
dioxacyclonona-3,7-dienes 5. Cross-coupling of 3 with two
different ketones 4 and 6 to give 7 can be achieved under
certain reaction conditions. Hydrolysis of 5 or 7 may generate
diketones 9, cyclopentanols 10/11, or cyclopentenes 12/13,
cyclopentadienyl)-substituted titanaheterocycle containing
carbon, is presented. Ab initio calculations were performed
for 5a and for titana-2-oxacyclopentene 1, a conceivable
intermediate in the coupling reaction.
Introduction
on the title complexes 5 and on conceivable intermediates
like titana-2-oxacyclopent-3-enes 1, which are hitherto un-
Titanaheterocycles are known with ring sizes ranging
from three to ten and with different degrees of “unsatu-
ration”. Whereas most of the publications focussed on sys-
known[ in contrast to their zirconium analogues
16]
[17]
and
their isomers, the titanacyclopent-4-enes 2.[
9][10]
[
1]
[2][3][4]
[4][5]
tems featuring four- , six-
, eight-
or ten-mem-
Results and Discussion
[
5]
bered rings, we were interested in the chemistry of the
odd-numbered chelate complexes, like titanaheterocyclo-
Synthesis of “Symmetric” Titana-2,9-dioxacyclonona-3,7-dienes 5;
Scope and Limits
[
3]
propanes,
titanaheterocyclopentanes
and
-pen-
[
4][5][6][7][8][9][10][11]
tenes,
or titana-2,7-dioxacyclohepta-3,5-
We have recently shown that α,β-unsaturated arylketones
[
6][11][12]
dienes.
Structurally characterized nine-membered (e.g. 4a) readily react under mild, non-basic conditions with
titanacycles are known as well, but most of them lack car- dicarbonyltitanocenes 3[
18]
to furnish the corresponding
[4][13]
bon in their metallacycle, as for instance TiS systems.
nine-membered bis-unsaturated metallacycles 5 right away
8
[
14]
5
We reported
on the synthesis of “carbon-rich” bis(η - without five-membered species of type 1 being detectable
cyclopentadienyl)titanadioxacyclononadienes 5 by a novel intermediates[ . Oxidative addition of two ketone units,
14]
coupling of two α,β-unsaturated ketones with Cp Ti(CO) , loss of two equivalents of CO and exclusive trans-β,β coup-
2
2
and recently Okuda[ published the X-ray structures of ling are the features of this reaction, which at first seemed
15]
nine-membered titanacycles built up from a 2,2Ј-ethylene- to be restricted to bis(aryl)-substituted ketones, though.
bisphenol and simple TiR precursors. We now present the
structure and preparative use of the titanacycles 5, as well
4
Scheme 1
as cross-coupling variants of our reaction with two different
ketones. We also took a closer look at the mechanism of
the coupling process and performed ab initio calculations
Figure 1. Unknown (1) and stable (2) 1-titana-2-oxacyclopentenes
Eur. J. Inorg. Chem. 1998, 1253Ϫ1262

WILEY-VCH Verlag GmbH, D-69451 Weinheim, 1998
1434Ϫ1948/98/0909Ϫ1253 $ 17.50ϩ.50/0
1253

F. Hampel, N. van Eikema Hommes, S. Hoops, F. Maaref, R. Schobert
FULL PAPER
2
We now found, that the residues R may also be aliphatic Scheme 3
1
to give equally high yields of 5 (5b), whereas R adjacent
to the carbonyl function is more crucial to the course of
the reaction. Aryl groups, alkyl systems not bearing an α-
hydrogen atom, like tert-butyl (5c), or vinyl units are com-
1
patible as R . Ketones 4 with methyl or saturated primary
or secondary alkyl groups next to the carbonyl function do
usually not give any metallacycles 5 on reaction with 3 in
isolable yields.
α,β;γ,δ-Bis(unsaturated) ketones (4d) do not give metalla-
cycles with larger rings but merely the corresponding vinyl-
substituted cyclononadienes (5d). Remarkably, reaction of
3
with the tris(unsaturated) ketone 4e yields exclusively the
symmetric 5,6-diphenyl-substituted derivative 5e by a β,β- Table 1. Symmetric titanadioxacyclononadienes 5 from 3 and keto-
nes 4[
a]
CϪC coupling at the “short ends” of the trienones. This
pathway may be preferred due to kinetic reasons or due to
5
R1
R2
Yield[b] m.p.[c]
the highest degree of olefinic conjugation of the product
compared with 11- or 13-membered metallacycles, which
would result from β,δ-CϪC and δ,δ-CϪC coupling reac-
tions, respectively. Reactions of 3 with carbocyclic ketones
like 4f also give rise to the corresponding metallacycles like
a
b
c
d
e
f
Ph
Ph
52
63
70
85
55
93
12
204
170
181
125
135
125
170
Ph
Me
tBu
Ph
Ph
PhCHϭCH
Ph
PhCHϭCHCHϭCH
see Scheme 2
Me
5
f without providing evidence for the intermediacy of Ϫ
Ph
g
see Scheme 3
now bicyclic and thus in principle more stable Ϫ species of
type 1. 5f is also the first derivative carrying substituents at
each ring carbon atom.
[a]
Conditions: 24 h, room temperature, 1 mmol of 3, 2 mmol of 4.
[b]
[c]
Ϫ
Isolated yield in [%] based on 4. Ϫ M. p. in [°C].
Scheme 2
analysis could be obtained from a solution in toluene kept
in the dark at room temperature for twenty days. To our
knowledge, the structure obtained from these crystals is the
first one of an unsaturated nine-membered titanacycle ex-
cept for the non-cyclopentadienyl systems Ti[2,2Ј-ethyl-
enebis(6-tert-butyl-4-methylphenolato)]X2[
OiPr, CH (SiMe ) ].
15]
[X
ϭ
Br,
2
3 2
Figure 2. Molecular structure of 5a; hydrogen atoms are omitted[a]
The most attractive extension of this basic reaction would
be cross-coupling variants of 3 with two different unsatu-
rated carbonyl moieties. Intramolecular cross-coupling does
not take place, however, with ketones bearing a second un-
saturated keto or ester group at an appropriate distance.
Reaction of 3 with the keto ester 4g, for instance, proceeds
with 1:2 stoichiometry and with formation of titanacycle 5g
in low yield. Although bearing an α-hydrogen atom at a
1
saturated residue R , complex 5g is as stable as more typical
derivatives of 5 bearing vinyl, aryl or tert-butyl residues at
C3 and C8. 5g is the only example of a titanacycle with this
structural feature.
Table 1 shows a representative collection of new “sym- C3ϪC4 1.344, C4ϪC5 1.494, C5ϪC6 1.587, C6ϪC7 1.506, C7ϪC8
metric” titanadioxacyclononadienes prepared from 4 and 3
[
a]
˚
Selected bond lengths [A], angles [°] and dihedral angles [°]:
Ti1ϪO2 1.885, Ti1ϪO9 1.892, O2ϪC3 1.359, O9ϪC8 1.356,
1
.346; Ti1ϪO2ϪC3 144.7, Ti1ϪO9ϪC8 143.1, O2ϪTi1ϪO9 101.8,
O2ϪC3ϪC4 121.0, O9ϪC8ϪC7 121.7, C3ϪC4ϪC5 124.3,
C4ϪC5ϪC6 110.8, C5ϪC6ϪC7 111.5, C6ϪC7ϪC8 123.1;
Ti1ϪO2ϪC3ϪC4 Ϫ67.9, Ti1ϪO9ϪC8ϪC7 Ϫ63.6, O2ϪTi1Ϫ
O9ϪC8 68.6, O2ϪC3ϪC4ϪC5 5.0, O9ϪTi1ϪO2ϪC3 68.0,
C3ϪC4ϪC5ϪC6 Ϫ58.1, C3ϪC4ϪC5ϪC15 174.2, C4ϪC5Ϫ
C6ϪC7 150.8, C4ϪC5ϪC6ϪC16 Ϫ78.6, C5ϪC6ϪC7ϪC8 Ϫ62.0,
C5ϪC6ϪC16ϪC26 Ϫ90.9, C6ϪC5ϪC15ϪC25 93.4, C6ϪC7Ϫ
C8ϪO9 2.9, C15ϪC5ϪC6ϪC7 Ϫ79.3, C15ϪC5ϪC6ϪC16 51.3,
in a 2:1 stoichiometry.
X-ray Crystal Structure of Complex 5a
So far, only a few titanaheterocycles with ring sizes larger
than six have been characterized by X-ray analysis[
5][13]
.
Single crystals of 5a suitable for an X-ray crystal structure C16ϪC6ϪC7ϪC8 167.9.
1254
Eur. J. Inorg. Chem. 1998, 1253Ϫ1262

Novel Nine-Membered Titanaheterocycles
Scheme 4
FULL PAPER
6 of sufficiently different reactivity towards 3. In principle,
three distinct products could result from reactions of a mix-
ture of 3, 4, and 6. Formation of complex 8 from 3 and two
equivalents of the more reactive ketone 6 can be supressed
by dropwise addition of 6 to a mixture of 4 (lower reactiv-
ity) and 3. The ratio of chelate complexes 5 and 7 is strongly
influenced by the reaction temperature. The yields of the
cross-coupled products 7 increase markedly with increasing
temperature. Best results are obtained by preparing a mix-
ture of 3 and 4 at 50°C, followed immediately by dropwise
addition of 6. Only cases where 7 is formed exclusively are
of synthetic interest, as separation of mixtures of 5, 7, and
8
is cumbersome due to their lack of air-stability and to
similar chromatographic behaviour. Table 2 shows a couple
of such well-defined examples.
5
a features roughly C symmetry about an axis through
2
the titanium atom and the opposite ring bond between C5
and C6. All bonds of the chelate have lengths as expected,
with only small differences for the pairs of corresponding
bonds. Only the C5ϪC6 bond (1.59 A) is slightly longer
than an average carbonϪcarbon single bond (1.55 A).The
adjoining bonds (C4ϪC5 and C6ϪC7) are both roughly
.50 A long. The CϭC bonds C3ϪC4 and C7ϪC8 have
lengths of 1.34 and 1.35 A. Both CϪO bonds have very
similar lengths (1.36 A), as have the TiϪO bonds (1.89 A).
The cyclopentadienyl rings in 5a are staggered by an angle
of 132°. In contrast, the few other published nine-mem-
bered Cp Ti-chelates all show eclipsed Cp ligands.
titanium atom is coordinated pseudo-tetrahedrally, with the
Hydrolysis of Titanadioxacyclononadienes 5 and 7
˚
Acidic hydrolysis of the “symmetric” titanacycles 5 leads
to only one racemic pair of highly substituted cyclopenta-
˚
nols 10, bearing four stereocentres, by a selective aldol reac-
˚
1
[14]
tion.
In most cases some diketone 9 and/or cyclopentene
˚
1
2 is formed as well but can be easily removed by column
˚
˚
chromatography. The trans orientation of the substituents
at C3 (B) and C4 (D) is defined in the course of the β-β
coupling leading to 5. The keto function at C2 then is ori-
ented trans to B and the hydroxy group at C1 is finally
formed cis to this keto group due to favourable hydrogen
bond interactions. The unambiguous assignment of the
relative stereochemistry of 10 and proof of the absence of
further diastereomers (or epimers) is based on NMR spec-
tra. Table 3 shows some new examples for the formation of
cyclopentanols 10 from titanacycles 5 to illustrate the wid-
ened scope and the limits of the method and the influence
of the solvent used for hydrolysis. As a rule of thumb, low
temperatures and the use of ethereal instead of aqueous
solutions of hydrogen chloride favour the formation of
cyclopentanols 10 over that of diketones 9. Hydrolysis of
the unusual titanacycle 5f gives rise to the interesting spiro
compound 10b (besides minor amounts of diketone 9b) fea-
turing five stereocentres about the central cyclopentane
core, although rather unselectively. All possible eight iso-
mers (plus enantiomers), when a trans orientation of the
[13]
The
2
angle OϪTiϪO being 102°, which is in the typical range.
The metallacyclic system is puckered about the C axis, the
2
angle between the OϪTiϪO plane and the opposite C5ϪC6
bond is roughly 90°, both CϭC bonds are cis configured.
In 5a, the angles TiϪOϪC are 143° and 145°, which are
common values for unstrained cycles. All four dihedral
angles including TiϪO segments are close to 70°, the di-
hedral angles C3ϪC4ϪC5ϪC6 and C5ϪC6ϪC7ϪC8 are
ca. 60°, and the angle C4ϪC5ϪC6ϪC7 is 151°. This results
in coplanarity of the phenyl groups at C5 and C6, which
are oriented formally trans to each other. Crystals of 5a
pertinaciously contain half an equivalent of toluene per
molecule.
Synthesis of Cross-Coupled Nine-Membered Metallacycles 7
“
Unsymmetric” cross-coupled titanacycles 7 can be pre- phenyl groups is assumed, are found in rather arbitrary ra-
pared in special cases from two unsaturated ketones 4 and tios and can be separated by HPLC. Hydrolyses of the “un-
Table 2. Titanadioxacyclononadienes 7 from two different ketones 4/6[a]
7
R1
R2
R3
R4
Yield[b]
m.p.[c]
starting
compounds
[
e]
a
b
c
p-(MeO)C
p-(MeO)C
p-(MeO)C
Ph
6
6
6
H
H
H
4
4
4
CHϭCHPh
CHϭCHPh
CHϭCHPh
CHϭCHPh
CHϭCHPh
CHϭCHPh
CHϭCHPh
Ph
Ph
69
60
65
68
66
81
65
101
115
114
Ϫ
160
152
79
4h, 6a
4h, 6b
4h, 6c
4e, 6d
4e, 6b
4e, 6c
o,p-(MeO)
2
C
6
6
6
H
4
3
3
Ph
p-(MeO)C
H
H
Ph
d
p-(MeO)C
4
H
6 4
p-(MeO)C H
[
d]
e
f
Ph
o,p-(MeO)
2
C
6
Ph
Ph
Ph
Ph
Ph
6 4
p-(MeO)C H
[
e]
g
Ph
4e, 6a
[
a]
[b]
Conditions: 1 h, 50°C, 1 mmol of 3, 1 mmol of 4, 1 mmol of 6, dropwise addition of 6. Ϫ Isolated yield in [%] based on 4 and 6.
Ϫ [ M.p. in [°C]. Ϫ Additionally, 7% of 5d was obtained. Ϫ Identical to 4a.
c]
[d]
[e]
Eur. J. Inorg. Chem. 1998, 1253Ϫ1262
1255

F. Hampel, N. van Eikema Hommes, S. Hoops, F. Maaref, R. Schobert
Table 3. Hydrolysis of titanacycles 5 and 7 with ethereal (C) and aqueous (D) hydrogen chloride
FULL PAPER
9؊13
method[a]
9
10
yield
11
yield
12
yield
13
yield
starting
compound
yield[
b]
[b]
[b]
[b]
[b]
[
[
[
[
c]
c]
c]
c]
a
a
b
c
d
e
e
f
D
C
C
D
D
D
C
C
89
35
13
9
5d
5d
5f
5g
7d
7e
7e
7f
42
80
45
10
11
56
55
7
8
35
38
25
27
[
a]
2 2
Method C: excess HCl in Et O, 3 h, Ϫ10°C; method D: excess HCl in H
O, 3 h, room temperature. Ϫ [b] Isolated yield in [%] based
[
c]
on 4 and 6. Ϫ 11 identical to 10.
Scheme 5. Hydrolysis of titanadioxacyclononadienes 5[a] and 7
Figure 3. MP2-optimized structures of titana-2-oxacyclopentenes 1
1,2 1,2 [a]
(
R
ϭ H), left, and 2 (R ϭ H), right
[
a]
˚
Selected bond lengths [A] and angles [°]: 1: TiϪO 1.9734, TiϪC3
.4512, TiϪC4 2.5199, TiϪC5 2.2670, C3ϪC4 1.3942, C4ϪC5
.4461; TiϪOϪC3 93.8; 2: TiϪO 1.8280, TiϪC5 2.1638, C3ϪC4
2
1
1
.5031, C4ϪC5 1.3524; TiϪOϪC3 125.2.
ular CϪC single and double bonds (bond lengths are 1.506
and 1.343 A, respectively). The computed values agree well
with those obtained in the crystal structure determination
of the diphenyl derivative, the main difference being a slight
[
a]
1
3
˚
If 5 is involved instead of 7, for all compounds applies R ϭ R
2
4
and R ϭ R ; only one regioisomer of cyclopentanol (designated
0 in Table 3) or cyclopentene is possible.
1
folding of the five-membered ring in the experimental struc-
symmetric” titanacycles 7 are of little synthetic use, as lead-
ing merely to mixtures of alcohols 10/11 and of cyclopen-
tenes 12/13. Two typical examples are enclosed in Table 3.
[9][10]
ture.
In the computed structure of 1, however, the ring
is strongly folded, with significant delocalization (CϪC
˚
bond lengths are 1.446 and 1.394 A for the formal single
and double bonds, respectively). As far as we know, no bis-
Ab Initio Calculations on Five- and Nine-Membered Metallacycles
(
cyclopentadienyl)-substituted five-membered titanacycles
As mentioned above, all our attempts to obtain even with structures deviating significantly from planarity are
trace amounts of the expected intermediate titana-2-oxacy- published. Thus, instead of a titanacyclopentene with a
clopent-3-enes 1 instead of the exclusively formed corre- TiϪC σ bond, our calculations predict a strong interaction
sponding nine-membered titanacycles 5 were unsuccessful. of the titanium centre with the CH moiety and the CϪC
2
On the other hand, stable examples of the isomeric titana-2- double bond in a π-allylic fashion. While unusual in orga-
oxacyclopent-4-ene 2 have been reported by several research notitanium compounds, π-allylic bonding is common for
˚
groups. In order to understand this difference, we per- the later transition metals. With 2.267 A, the computed
˚
formed ab initio (MP2) and hybrid density functional TiϪCH distance is roughly 0.1 A longer than a regular
2
(
B3LYP) calculations on 1, 2, 5, and some related spe- TiϪC single bond. The distances to the double bond car-
[
19][20][21][22][23]
˚
cies.
With one exception (see below), both bon atoms are 2.451 and 2.520 A. Due to the short distance
methods yield essentially the same results. The calculated between the metal centre and the double bond, an excep-
geometries are in good agreement with available experimen- tionally small value of 94° results for the TiϪOϪC angle.
tal data. Figure 3 shows the MP2-optimized structures of 1 Analysis of the electronic structure reveals a strong do-
and 2.
nation from the π-bond to the metal centre and an in-
Titana-2-oxacyclopent-3-ene 1 is computed to be 10 kcal/ creased polarity of the TiϪCH σ bond. Thus, 1 is best
2
mol more stable than its isomer 2. The five-membered ring described as a C-nucleophilic electron-rich (18 valence elec-
in 2 is planar, with bond lengths and angles indicating reg- trons) allyl complex.
1256
Eur. J. Inorg. Chem. 1998, 1253Ϫ1262

Novel Nine-Membered Titanaheterocycles
FULL PAPER
Two conformations are possible for 5, which differ in the Schlenk-type glassware. Solvents were dried and distilled under ar-
gon prior to use according to standard procedures. The starting
orientation of the organic fragment with respect to the
complex 3[ as well as most of the unsaturated ketones were pre-
18]
Cp TiO moiety. The geometric data of the experimental
2
2
[24]
[25]
[26]
pared as published [4b
p-methoxyphenyl)-5-phenylpentadien-1-one][25], 6b؊d
condensation]. Compound 4a (ϭ 6a) is commercially available
Fluka). Ϫ Melting points are not corrected, boiling points quoted
by Wittig reaction, 4cϪe , 4f , 4h [1-
conformer are in good agreement with the X-ray structure.
The relative stability of the two conformers is predicted dif-
ferently by the MP2 and B3LYP methods, although the ac-
tual difference is small. At MP2/TZ2p, the experimental
conformer is 1.2 kcal/mol more stable, whereas B3LYP/
TZ2p predicts it to be less stable by 1.1 kcal/mol.
[25]
(
by aldol
(
for Kugelrohr distillations refer to the temperature of the air bath.
Ϫ NMR: Jeol JNMX GX-400 and PMX-60; δ given in ppm; TMS
as internal standard. Ϫ IR: Bruker IFS 48, Beckmann Acculab A1,
A possible route to 5 involves addition of 1 to propenal. A3. Ϫ MS: Varian MAT CH-4B (EFO-4B-source), Varian MAT
This reaction is calculated to be 49 kcal/mol exothermic. 311A (EI/FD source). Ϫ MA: Heraeus Mikromat C-H-N. Ϫ
HPLC: Shimadzu LC-10 AT, SIL-10 A, CBM 10 A, SPD-10 M
A, FCV-10 AL; column: Macherey-Nagel Nucleosil ET 200/4. Ϫ
The activation barrier appears to be very low: several at-
tempts, with different starting geometries, were made to
compute the structure of the initial complex for the ad-
dition but in all cases, the structure collapsed to 5 during
Isomeric ratios were determined from the relative intensities of the
1
pertaining H-NMR signals or by analytic HPLC.
the optimization. We believe the combination of the un-
1. Synthesis of Ketone 4g. Ϫ Synthesis of Methyl (o-Formyl-trans-
usual bonding features in 1, in particular the lengthening cinnamate): 2.24 g (16.7 mmol) of phthaldialdehyde were dissolved
in 40 ml of THF and stirred at 60°C. A solution of 4.95 g (16.7
and corresponding weakening of the TiϪCH bond, and
the significant exothermicity of the reaction to be respon-
sible for this behaviour.
We probed alternative mechanisms via complexes of ti-
tanocene and two propenal moieties. These gave the same
result as above (optimization leads to 5 without activation
barrier), but in all cases, high-energy intermediates must be
2
[
27]
mmol) of (methoxycarbonylmethylene)triphenylphosphorane
00 ml of THF was added dropwise over a period of 1 h and the
mixture was then stirred overnight. The solvent was then removed
in vacuo and most of the PPh O by repeated chromatography over
silica gel using neat CH Cl as the eluent. GC analysis of the eluate
showed 58% of product, 17% of starting dialdehyde, 10% of
double-olefination product, and 8% of PPh O. Final purification
in
1
3
2
2
3
involved. Hence, we consider these alternatives less prob- by Kugelrohr distillation (110Ϫ120°C, 0.5 mbar) gave 1.54 g (8.0
1
able than reaction via 1.
mmol; 48%) of the cinnamate as a bright yellow viscous oil. Ϫ H
3
NMR (60 MHz, CDCl
Hz, 1 H, CHϭCHCϭO), 7.4Ϫ7.9 (m, 4 H, H ), 8.5 (d, J ϭ 16
Hz, 1 H, CHϭCHCϭO), 10.2 (s, 1 H, CHO). Ϫ C11 (190.20):
calcd. C 69.47, H 5.30; found C 69.11, H 5.63. Ϫ Synthesis of
3 3
): δ ϭ 3.8 (s, 3 H, CH ), 6.3 (d, J ϭ 16
ar
3
Conclusions
10 3
H O
By careful choice of conditions, novel nine-membered ti-
tanadioxacycles 5 and 7 can be prepared from α,β-unsatu- Methyl [(o-3Ј-Oxobutenyl)-trans-cinnamate] (4g): 1.54 g (8.08
rated ketones with a broad variety of substituents. The X- mmol) of methyl (o-formyl-trans-cinnamate) was dissolved in 30 ml
ray analysis of the tetraphenyl derivative 5a revealed a C2- of THF and stirred at 40°C. A solution of 2.37 g (8.08 mmol)
of (2-oxopropylene)triphenylphosphorane[ in 50 ml of THF was
28]
symmetric puckered structure with two Z-configured CϭC
bonds and a trans orientation of residues about the newly
formed CϪC bond. Acidic hydrolysis of these chelate com-
plexes is synthetically useful in case of “symmetrically” sub-
stituted derivatives 5, where highly substituted cyclopen-
tanes 10 are obtained as one racemic pair of stereoisomers
out of eight possible ones, due to selectivity in the CϪC
added dropwise and the resulting mixture was stirred at 50°C over-
night. The solvent was then removed to leave a crude product which
was purified by CC (silica gel; CH
2
Cl
2
): 1.15 g (4.99 mmol; 62%);
): δ ϭ 2.4 (s,
), 6.30 (d, J ϭ 16 Hz, 1 H,
), 6.55 (d, J ϭ 16 Hz, 1 H, CHϭCHCOCH ),
.2Ϫ7.65 (m, 4 H, H ), 7.85 (d, J ϭ 16 Hz, 1 H, CHϭ
1
pale solid; m.p. 46°C. Ϫ H NMR (60 MHz, CDCl
3
3
3
H, CH
3 3
CO), 3.8 (s, 3 H, OCH
3
CHϭCHCO
7
2
CH
3
3
ar
3
3
bond formation process and to steric restraints and prefer- CHCOCH ), 8.0 (d, J ϭ 16 Hz, 1 H, CHϭCHCOOCH ) .Ϫ
3
3
ences. Ab initio calculations on the nine-membered rings 5 C H O (230.27): calcd. C 73.03, H 6.13; found C 73.14, H 5.90.
1
4
14
3
and on conceivable five-membered intermediates were per-
formed. For the expected intermediate complex 1 of our
coupling reaction, an unusual structure of high reactivity of
the TiϪC σ bond due to an interaction of the titanium
2
. Synthesis of 5. Ϫ General Procedure (A): The respective α,β-
unsaturated ketone 4 (2 mmol) was added to a solution of 3 (234
mg; 1 mmol) in toluene (15 ml) and the resulting mixture stirred at
0°C for 3 h. Once the starting materials were completely con-
4
centre with the CH moiety and the CϪC double bond in sumed, 5 ml of hexane was added to give a precipitate which was
2
a π-allylic fashion was calculated, thus providing an expla- collected on a sinter funnel, washed twice with hexane and dried
nation for its elusive character. Further work is in progress in vacuo. For analytical purposes samples of 5 were recrystallized
from CH
2
Cl
2
/hexane (2:1).
now to prepare titanacycles with even larger rings by similar
CϪC coupling reactions or by Cope rearrangement of aptly
substituted nine-membered systems like 5d.
5
(
±)-(5,6-threo-3Z,7Z)-1,1-Bis(η -cyclopentadienyl)-3,5,6,8-
[29]
tetraphenyl-1-titana-2,9-dioxacyclonona-3,7-diene (5a)
: 3.50 g
(
5.89 mmol; 52%) from 2.65 g of 3 and 4.71 g of 4a; dark red air-
Financial support from the Volkswagen-Stiftung and the Fonds
der Chemischen Industrie e. V. is gratefully acknowledged.
sensitive crystals from toluene; m.p. 204°C. Ϫ IR (KBr): ν˜ ϭ 3040
cm , 3030, 3020, 1600, 1490, 1450, 1330, 810, 750, 700. Ϫ
NMR (400 MHz, C
6
Ϫ1
1
H
[30]
3
6
D
6
)
: δ ϭ 5.03 (d, J ϭ 5.50 Hz, 2 H, 5-H,
Experimental Section
3
-H), 5.89 (d, J ϭ 5.50 Hz, 2 H, 4-H, 7-H), 5.95 (s, 10 H, Cp),
ar
3
ar
3
General Information: All reactions involving organometallic 7.07 (m, 10 H, H ), 7.21 (t, J ϭ 7.15 Hz, 2 H, H ), 7.31 (t, J ϭ
ar
3
ar
13
compounds were carried out in an inert atmosphere (argon) using
7.15 Hz, 4 H, H ), 7.59 (d, J ϭ 7.15 Hz, 4 H, H ). Ϫ C NMR
Eur. J. Inorg. Chem. 1998, 1253Ϫ1262
1257

F. Hampel, N. van Eikema Hommes, S. Hoops, F. Maaref, R. Schobert
6 6 38 2
D ): δ ϭ 48.1 (C-5, C-6), 106.8 (C-4, C-7), 116.2 (%): 542 (7), 348 (7), 382 (38), 234 (45), 105 (100). Ϫ C44H O Ti
FULL PAPER
(
(
(
100.4 MHz, C
ar
Cp), 125.0, 126.1, 127.4, 128.1, 128.7, 129.9 (CH ), 140.6, 143.2
(646.69): calcd. C 81.73, H 5.88; found C 81.87, H 6.02.
ϩ
ipso-C), 163.8 (C-3, C-8). Ϫ MS (70 eV); m/z (%): 386 (6) [M
Ϫ
5
(
±)-(5,6-threo-3Z,7Z)-1,1-Bis(η -cyclopentadienyl)-3,8-bis-δ-
ϩ
ϩ
PhCHϭCHCOPh], 207 (96) [PhCOCHϭCPh ], 178 (49) [Cp
2
Ti ],
(
phenyl-trans,trans-butadienyl)-1-titana-2,9-dioxa-5,6-diphenyl-
cyclonona-3,7-diene (5e): 384 mg (0.55 mmol; 55%) from 234 mg of
and 520 mg of 4e; dark red air-sensitive needles from toluene;
ϩ
ϩ
1
05 (61) [PhCO ], 77 (100) [Ph ]. Ϫ C40
H O Ti (594.34): calcd.
34 2
C 80.83, H 5.72; found C 80.68, H 5.78.
3
X-ray Crystal Structure Analysis of 5a[31][32]: Clear, dark red sin-
gle crystals of 5a ϫ toluene were obtained directly from the reac- 785, 750. Ϫ H NMR (400 MHz, C
m.p. 135°C. Ϫ IR (KBr): ν˜ ϭ 3065Ϫ3024 cm , 1580, 1565, 1490,
Ϫ1
1
[30]
3
6
D
6
)
: δ ϭ 4.92 (d, J ϭ 5.61
3
tion mixture upon standing 2 d in the dark. Formula C44
H
34
O
2
Ti,
Hz, 2 H, 5-H, 6-H), 5.35 (d, J ϭ 5.61 Hz, 2 H, 4-H, 7-H), 5.98 (s,
Ϫ1
ar
molar mass 642.61 g mol , crystal size 0.5 ϫ 0.3 ϫ 0.1 mm, a ϭ
10 H, Cp), 6.22Ϫ7.52 (m, 28 H, CHϭCH-CHϭCH and H ). Ϫ
˚
13
1
3
5.924(3), b ϭ 8.347(2), c ϭ 24.558(5) A, β ϭ 99.34(3)°, V ϭ
6 6
C NMR (100.4 MHz, C D ), δ ϭ 48.6 (C-5, C-6), 114.9 (C-4, C-
˚
3
Ϫ3
221.1(11) A , T ϭ 173(2) K; dcalcd. ϭ 1.325 g cm , µ ϭ 3.05 7), 115.8 (Cp), 125.6, 126.1, 126.6, 126.7 (CHϭCHCHϭCH),
Ϫ1
ar
cm , Z ϭ 4, monoclinic, space group P2(1)/c, Nonius MACH3
129.1, 129.7, 129.8 (CH ), 138.2, 144.2 (ipso-C), 163.6 (C-3, C-8).
˚
diffractometer, λ ϭ 0.71037 A, Θ range 2.58Ϫ24.98°; ω/Θ scans, Ϫ MS (70 eV); m/z (%): 488 (15), 448 (35), 460 (65), 260 (100), 178
ϩ
index ranges Ϫ18 Յ h Յ 18, Ϫ9 Յ k Յ 0, Ϫ29 Յ l Յ 0, 5794 (76) [Cp
2
Ti ]. Ϫ C48
H
42 2
O Ti (698.77): calcd. C 82.52, H 6.01;
collected reflections, 2625 reflections [I > 2σ(I)], 428 refined param-
eters, absorption correction with Ψ scans. Structure solution: direct
methods (SHELXS86); structure refinement: full-matrix least
found C 82.71, H 6.16.
5
(
±)-(5,6-threo)-1,1-Bis(η -cyclopentadienyl)-5,6-diphenylbis-
indeno[3,2-c;2Ј,3Ј-g]-1-titana-2,9-dioxa-cyclonona-3,7-diene
80 mg (0.6 mmol; 93%) from 154 mg of 3 and 440 mg of 4f; dark
red air-sensitive needles from toluene; m.p. 125°C (decomp.). Ϫ IR
(5f):
2
squares on F (SHELXL93), H atoms calculated and not included
3
into least-squares refinement. In the unit cell two additional
strongly disordered toluene molecules were found. R1 ϭ 0.0746,
wR2 ϭ 0.2265 (all data), largest diff. peak and hole 0.552 and
Ϫ1
1
(
CDCl
3
): ν˜ ϭ 3068 cm , 2961, 2878,1572, 1559. Ϫ H NMR (400
[30]
2
MHz, CDCl
3
)
: δ ϭ 3.11 (d, J ϭ 22.10 Hz, 2 H, CHHЈ), 3.24
d, J ϭ 22.10 Hz, 2 H, CHHЈ), 5.10 (s, 2 H, 5-H, 6-H), 6.47 (s, 10
˚
Ϫ3
2
Ϫ0.747 eA with R1 ϭ Σ͉F
o
Ϫ F
c
͉/ΣF
o
and wR2 ϭ {Σw(F
o
Ϫ
2
(
2
2
2 2 0.5
F
c
) /Σ[w(F
o
) }
.
ar
ar
H, Cp), 7.01 (m, 4 H, H of C
6
H
5
), 7.04 (m, 2 H, H of C
6
H
5
ar
),
5
3
ar
(
±)-(5,6-threo-3Z,7Z)-1,1-Bis(η -cyclopentadienyl)-5,6-di- 7.04 (dd, J ϭ 7.44, 7.44 Hz, 2 H, H of C
6
H
4
), 7.08 (m, 4 H, H
3
ar
3
methyl-1-titana-2,9-dioxa-3,8-diphenylcyclonona-3,7-diene (5b): 296
mg (0.63 mmol; 63%) from 234 mg of 3 and 444 mg of 4b; dark 7.44 Hz, 2 H, H of C
red air-sensitive needles from toluene; m.p. 170°C. Ϫ IR (KBr):
of C
6 5 6 4
H ), 7.16 (d, J ϭ 7.44 Hz, 2 H, H of C H ), 7.23 (d, J ϭ
ar
3
ar
6
H
4
), 7.26 (dd, J ϭ 7.44, 7.44 Hz, 2 H, H
1
3
of C
6
H
4
). Ϫ C NMR (100.4 MHz, CDCl ): δ ϭ 36.2 (4-C, 7-C),
3
Ϫ1
1
ar
ν˜ ϭ 3058 cm , 2961, 1680, 1447, 1271, 803. Ϫ H NMR (400 49.7 (C-5, C-6), 116.7 (Cp), 117.0 (CH ), 119.7 (C-4, C-7), 123.7,
[
30]
3
ar
6
MHz, C D
6
)
: δ ϭ 1.18 (d, J ϭ 7.14 Hz, 6 H, CH
3
), 3.36 (m, 2
123.8, 125.5, 125.7, 127.4, 129.8 (CH ), 142.0, 143.2, 143.7 (ipso-
3
ϩ
H, 5-H, 6-H), 5.49 (d, J ϭ 5.50 Hz, 2 H, 4-H, 7-H), 5.90 (s, 10 H, C), 162.0 (C-3, C-8). Ϫ MS (70 eV); m/z (%): 406 (60) [M
Cp), 7.16Ϫ7.57 (m, 10 H, H ). Ϫ C NMR (100.4 MHz, C
Ϫ
ar
13
ϩ
6
D
6
): Cp
2
Ti(OH)
2
], 333 (93), 219 (40), 66 (100) [CpH ]. Ϫ C42
H
34
O
2
Ti
δ ϭ 15.7 (5-C, 6-C), 33.5 (C-5, C-6), 109.8 (C-4, C-7), 115.8 (Cp), (618.64): calcd. C 81.55, H 5.50; found C 81.63, H 5.44.
ar
1
25.3, 126.1, 127.1 (CH ), 140.1 (3-C, 8-C), 163.8 (C-3, C-8). Ϫ
5
(
±)-(5,6-threo-3Z,7Z)-1,1-Bis(η -cyclopentadienyl)-3,8-di-
MS (70 eV); m/z (%): 276 (10), 178 (65) [Cp Ti], 171 (25), 105 (100)
2
methyl-5,6-bis(o-methyl-trans-cinnamoyl)-1-titana-2,9-dioxa-
cyclonona-3,7-diene (5g): 95 mg (0.15 mmol; 12%) from 567 mg 3
and 460 mg 4g; dark red air-sensitive needles from toluene; m.p.
ϩ
[C
6
H
5
CO ]. Ϫ C30
H
30
O
2
Ti (470.47): calcd. C 76.59, H 6.38; found
C 76.20, H 5.97.
5
Ϫ1
(
±)-(5,6-threo-3Z,7Z)-1,1-Bis(η -cyclopentadienyl)-3,8-di-tert- 170°C (decomp.). Ϫ IR (CH
butyl-1-titana-2,9-dioxa-5,6-diphenylcyclonona-3,7-diene (5c): 390 1165. Ϫ H NMR (400 MHz, CDCl
mg (0.7 mmol; 70%) from 234 mg of 3 and 528 mg of 4c; dark red
air-sensitive needles from toluene; m.p. 181°C. Ϫ IR (KBr): ν˜ ϭ (d, J ϭ 5.70 Hz, 2 H, 4-H, 7-H), 6.07 (d, J ϭ 8.10 Hz, 2 H, H ),
058 cm , 2952, 1604, 1452, 1306, 1079, 806. Ϫ H NMR (400
: δ ϭ 1.21 (s, 18 H, CH ), 4.22 (d, J ϭ 6.05 Hz, 2 (dd, J ϭ 7.10, 8.10 Hz, 2 H, H ), 7.09 (dd, J ϭ 7.10, 8.10 Hz, 2
3
H, 5-H, 6-H), 5.00 (d, J ϭ 6.05 Hz, 2 H, 4-H, 7-H), 6.01 (s, 10 H, H, H ), 7.56 (d, J ϭ 8.10 Hz, 2 H, H ), 8.32 (d, J ϭ 15.70 Hz,
Cp), 7.89Ϫ7.93 (m, 10 H, H ). Ϫ C NMR (100.4 MHz, C
2
Cl
2
): ν˜ ϭ 1710 cm , 1625, 1310,
1
[30]: δ ϭ 1.82 (s, 6 H, CCH
3
)
3
),
3
3.82 (s, 6 H, OCH ), 4.31 (d, J ϭ 5.70 Hz, 2 H, 5-H, 6-H), 4.92
3
3
3
ar
Ϫ1
1
3
3
6.35 (d, J ϭ 15.70 Hz, 2 H, CHϭCHCO), 6.40 (s, 10 H, Cp), 6.88
[
30]
3
3
ar
3
MHz, C
6
D
6
)
3
ar
3
ar
3
ar
13
13
6
D
6
): 2 H, CHϭCHCO). Ϫ C NMR (100.4 MHz, CDCl
3
): δ ϭ 23.0
δ ϭ 29.5 (CH ), 37.6 (3-C, 8-C), 47.8 (C-5, C-6), 101.7 (C-4, C-7), (3-C, 8-C), 42.2 (C-5, C-6), 51.4 (OCH
3
3
), 103.9 (C-4, C-7), 115.7
ar
ar
1
3
16.3 (Cp), 127.8, 128.4, 128.9 (CH ), 145.2 (5-C, 6-C), 173.2 (C- (Cp), 117.9 (CHϭCHCO), 125.8, 125.8, 128.4, 131.7 (CH ), 133.9
, C-8). Ϫ MS (70 eV); m/z (%): 378 (10), 321 (90), 278 (60), 189 (CCHϭCHCO), 143.0 (5-C, 6-C), 145.3 (CHϭCHCO), 164.4 (C-
ϩ
(
50), 131 (100). Ϫ C36
H
42
O
2
Ti (554.63): calcd. C 77.97, H 7.58; 3, C-8), 167.7 (CO
2
CH ). Ϫ MS (70 eV); m/z (%): 638 (2) [M ],
3
ϩ
found C 78.22, H 7.40.
408 (11) [M Ϫ C14H O ], 278 (16) [408 Ϫ 2 Cp], 219 (35)
14 3
ϩ
ϩ
[Cp
2
TiOCCH ], 178 (87) [Cp
2
Ti ], 128 (99), 43 (100). Ϫ
5
(
±)-(5,6-threo-3Z,7Z)-1,1-Bis(η -cyclopentadienyl)-5,6-bis-β-
C H O Ti (638.62): calcd. C 71.47, H 6.00; found C 71.42, H
38 38 6
(
trans-phenylethenyl)-1-titana-2,9-dioxa-3,8-diphenyl-
5
.81.
3. Synthesis of 7. Ϫ General Procedure (B): The respective α,β-
cyclonona-3,7-diene (5d): 549 mg (0.85 mmol; 85%) from 234 mg
of 3 and 468 mg of 4d; dark red air-sensitive needles from toluene;
m.p. 125°C. Ϫ IR (KBr): ν˜ ϭ 2850 cm , 1600, 1100, 800. Ϫ H unsaturated ketone 4 (1 mmol) was added at once to a solution of
Ϫ1
1
[30]
3
NMR (400MHz, C
6
D
6
)
: δ ϭ 4.46 (dd, J ϭ 4.94, 5.50 Hz, 2 H, 3 (234 mg; 1 mmol) in toluene (15 ml) at 50°C. Immediately there-
-H, 6-H), 5.98 (d, J ϭ 5.50 Hz, 2 H, 4-H, 7-H), 6.06 (s, 10 H, after, a solution of 1 mmol of the second ketone 6 in toluene (20
Cp), 6.80 (dd, J ϭ 4.98, 15.95 Hz, 2 H, CHϭCHPh), 6.98 (d, J ϭ ml) was added dropwise over a period of 30 min. Once the starting
3
5
3
3
ar
13
1
(
1
5.95 Hz, 2 H, CHPh), 7.11Ϫ8.07 (m, 20 H, H ). Ϫ C NMR
100.4 MHz, C ): δ ϭ 45.1 (C-5, C-6), 92.1, 92.7 (CHϭCHPh), 1 h), the solution was filtered at ambient temperature, 5 ml of hex-
02.2 (C-4, C-7), 116.2 (Cp), 126.4, 126.7, 127.9, 128.6, 129.7, 130.1 ane was added and the resulting precipitate was collected on a sin-
materials were completely consumed (NMR monitoring, typically
6 6
D
ar
(CH ), 145.2, 146.4 (ipso-C), 163.5 (C-3, C-8). Ϫ MS (70 eV); m/z ter funnel, washed twice with hexane and dried in vacuo. For ana-
1258 Eur. J. Inorg. Chem. 1998, 1253Ϫ1262

Novel Nine-Membered Titanaheterocycles
FULL PAPER
lytical purposes samples of 7 were recrystallized from CH
ane (2:1).
2
Cl
2
/hex-
needles from toluene. Ϫ IR (KBr): ν˜ ϭ 3008Ϫ2800 cmϪ1, 1595,
1
)[30][33]: δ ϭ
1480, 1245, 1070, 805. Ϫ H NMR (400 MHz, C
6
3
D
6
3
3 3
.03 (s, 3 H, CH ), 3.12 (s, 3 H, CH ), 4.16 (dd, J ϭ 5.62, 5.86
5
(
5,6-threo-3Z,7Z)-3-(p-Anisyl)-1,1-bis(η -cyclopentadienyl)-6,8-
3
3
Hz, 1 H, 6-H), 4.70 (d, J ϭ 5.62 Hz, 1 H, 5-H), 5.33 (d, J ϭ 5.62
diphenyl-5-(β-trans-phenylethenyl)-1-titana-2,9-dioxacyclonona-
,7-diene (7a): 448 mg (0.69 mmol; 69%) from 234 mg of 3, 264
3
Hz, 1 H, 7-H), 5.67 (s, 5 H, Cp), 5.70 (s, 5 H, Cp), 5.80 (d, J ϭ
3
3
5
.62 Hz, 1 H, 4-H), 5.90 (dd, J ϭ 5.86, 15.62 Hz, 1 H, CHϭ
mg of 4h and 208 mg of 4a (as the more reactive component); dark
red air-sensitive needles from toluene; m.p. 101°C. Ϫ IR (KBr):
3
CHPh), 6.34 (d, J ϭ 15.62 Hz, 1 H, CHϭCHPh), 6.35Ϫ7.82 (m,
ar
13
1
8 H, H ). Ϫ C NMR (100.4 MHz, C
C-6), 54.61, 54.67 (CH ), 112.2, 112.4 (C-4, C-7), 116.2 (Cp), 122.2,
23.1 (CHϭCHPh), 125.8, 126.3, 127.1, 127.9, 132.8, 134.5, 135.3,
36.8, 139.1, 139.9 (CH ), 142.1, 142.7 (ipso-C of C
50.8 (ipso-C of C OCH ), 159.4, 159.9 (COCH ), 163.0, 163.8
6 6
D ): δ ϭ 45.2, 47.2 (C-5,
Ϫ1
1
ν˜ ϭ 3025 cm , 2834, 1598, 1506, 1284, 811. Ϫ H NMR (400
[
30][33]
3
3
6
MHz, C D
6
)
: δ ϭ 3.42 (s, 3 H, CH
3
), 4.46 (dd, J ϭ 5.62,
1
1
1
3
3
5
.86 Hz, 1 H, 5-H), 4.84 (d, J ϭ 5.86 Hz, 1 H, 6-H), 5.49 (d, J ϭ
ar
6 5
H ), 150.2,
5
.62 Hz, 1 H, 4-H), 5.97 (s, 5 H, Cp), 6.02 (s, 5 H, Cp), 6.04 (d,
6
H
4
3
3
3
3
J ϭ 5.86 Hz, 1 H, 7-H), 6.15 (dd, J ϭ 5.86, 15.63 Hz, 1 H, CHϭ
CHPh), 6.63 (d, J ϭ 15.63 Hz, 1 H, CHϭCHPh), 6.92Ϫ7.62 (m,
(
C-3, C-8). Ϫ MS (70 eV); m/z (%): 444 (20), 324 (18), 178 (65)
3
ϩ
ϩ
40 4
[Cp2Ti ],105 (100) [PhCO ]. Ϫ C44H O Ti (680.7): calcd. C
ar
13
1
9 H, H ). Ϫ C NMR (100.4 MHz, C
C-6), 55.1 (CH ), 110.2, 112.9 (C-4, C-7), 116.1 (Cp), 125.1, 126.9
CHϭCHPh), 129.1, 129.7, 130.1, 130.7, 130.9, 134.1, 135.7, 137.2,
6 6
D ): δ ϭ 45.2, 47.5 (C-5,
7
7.64, H 6.15; found C 77.62, H 5.98.
3
(
1
5
(
5,6-threo-3Z,7Z)-1,1-Bis(η -cyclopentadienyl)-3-(o,p-dimeth-
ar
38.5, 138.9 (CH ), 141.2, 143.8, 144.3, 144.8 (ipso-C), 159.1
oxyphenyl)-5,8-diphenyl-6-β-(trans-phenylethenyl)-1-titana-2,9-di-
oxacyclonona-3,7-diene (7e): A mixture of 449 mg of 7e (0.66 mmol;
(
(
COCH
10), 456 (60), 365 (22), 295 (25), 208 (18) [PhCHϭCHCOPh ],
3
), 163.1, 163.9 (C-3, C-8). Ϫ MS (70 eV); m/z (%): 512
ϩ
6
6%) and 5d (0.07 mmol; 7%) from 234 mg of 3, 234 mg of 4d,
and 268 mg of 6b; ratio 7e/5d determined by NMR; 7e purified
by crystallization from CH Cl /hexane (2:1); dark red air-sensitive
needles from toluene, m.p. 160°C. Ϫ IR (KBr): ν˜ ϭ 3030Ϫ2820
105 (100). Ϫ C43
H
38
O
3
Ti (650.68): calcd. C 79.38, H 5.38; found
C 79.52, H 5.48.
2
2
5
(
5,6-threo-3Z,7Z)-8-(p-Anisyl)-1,1-bis(η -cyclopentadienyl)-3-
Ϫ1
1
cm , 1600, 1430, 1240, 1020, 810. Ϫ H NMR (400 MHz,
(
2
2
o,p-dimethoxyphenyl)-5-phenyl-6-β-(trans-phenylethenyl)-1-titana-
,9-dioxacyclonona-3,7-diene (7b): 426 mg (0.6 mmol; 60%) from
34 mg of 3, 264 mg of 4h and 268 mg of 6b; dark red air-sensitive
[30][33]
C
6
D
6
)
: δ ϭ 3.36 (s, 3 H, CH
3 3
), 3.44 (s, 3 H, CH ), 4.56 (dd,
3
3
J ϭ 5.71, 5.86 Hz, 1 H, 6-H), 4.86 (d, J ϭ 5.86 Hz, 1 H, 5-H),
5.51 (d, J ϭ 5.71 Hz, 1 H, 7-H), 5.96 (d, J ϭ 5.86 Hz, 1 H, 4-
H), 6.05 (s, 5 H, Cp), 6.06 (s, 5 H, Cp), 6.19 (dd, J ϭ 5.86, 15.62
Hz, 1 H, CHϭCHPh), 6.67 (d, J ϭ 15.62 Hz, 1 H, CHϭCHPh),
3
3
Ϫ1
needles from toluene; m.p. 115°C. Ϫ IR (KBr): ν˜ ϭ 3025 cm
,
3
1
[30][33]:
2
934, 2836, 1600, 1254, 808. Ϫ H NMR (400 MHz, C
6
3
D
6
)
3
3 3
δ ϭ 3.35 (s, 3 H, CH ), 3.43 (s, 6 H, CH ), 4.58 (dd, J ϭ 5.86,
.86 Hz, 1 H, 6-H), 4.89 (d, J ϭ 5.86 Hz, 1 H, 5-H), 5.53 (d, J ϭ
.86 Hz, 1 H, 7-H), 6.03 (d, J ϭ 5.86 Hz, 1 H, 4-H), 6.07 (s, 5 H,
Cp), 6.08 (s, 5 H, Cp), 6.18 (dd, J ϭ 5.86, 15.86 Hz, 1 H, CHϭ
ar
13
3
3
6.70Ϫ7.92 (m, 18 H, H ). Ϫ C NMR (100.4 MHz, C
6 6
D ): δ ϭ
5
5
3
46.4, 48.1 (C-5, C-6), 55.3, 57.1 (CH ), 105.7, 107,2 (C-4, C-7),
3
3
117.1 (Cp),122.2, 122.9 (CHϭCHPh), 126.1, 128.4, 128.9, 129.2,
ar
3
130.1, 132.2, 133.1, 133.7, 134.1, 135.8, 137.1, 141.9 (CH ), 142.5,
CHPh), 6.76 (d, J ϭ 15.86 Hz, 1 H, CHϭCHPh), 6.90Ϫ7.68 (m,
ar
13
143.1, 143.9, 145.2 (ipso-C), 159.1, 160.1 (COCH
3
), 163.2, 165.1
1
7 H, H ). Ϫ C NMR (100.4 MHz, C
C-6), 54.7, 54.8, 54.9 (CH ), 113.9, 114.2 (C-4, C-7), 116.1 (Cp),
24.2, 126.7 (CHϭCHPh), 126.2, 126.9, 127.3, 127.8, 129.4, 132.3,
6 6
D ): δ ϭ 46.0, 48.1 (C-5,
(
C-3, C-8). Ϫ MS (70 eV); m/z (%): 405 (20), 377 (35), 342 (30),
3
1
78 (55), 77 (100). Ϫ C44
H
40
O
4
Ti (680.71): calcd. C 77.64, H 5.88;
1
1
(
ar
found C 76.47, H 5.78.
33.7, 134.5, 136.1, 137.8, 138.2 (CH ), 142.2, 142.9, 144.1, 144.8
), 162.2, 162.9 (C-3, C-8). Ϫ
MS (70 eV); m/z (%): 486 (42), 460 (10), 395 (15), 351 (30), 264
ipso-C), 158.5, 159.6, 160.6 (COCH
3
5
(
5,6-threo-3Z,7Z)-3-(p-Anisyl)-1,1-bis(η -cyclopentadienyl)-5,8-
diphenyl-6-β-(trans-phenylethenyl)-1-titana-2,9-dioxacyclonona-
,7-diene (7f): 527 mg (0.81 mmol; 81%) from 234 mg of 3, 234 mg
ϩ
2
(17) [C18
H
16
O
], 238 (20). Ϫ C45
H
42
O
5
Ti (710.73): calcd. C 76.05,
3
H 5.92; found C 75.94, H 5.88.
of 4d and 238 mg of 6c; dark red air-sensitive needles from toluene;
Ϫ1
5
m.p. 152°C. Ϫ IR (KBr): ν˜ ϭ 3040Ϫ2800 cm , 1610, 1450, 1250,
(
5,6-threo-3Z,7Z)-3,8-Bis(p-anisyl)-1,1-bis(η -cyclopenta-
1
[30][33]
1
3
5
100, 1030, 800. Ϫ H NMR (400 MHz, C
6
D
6
)
: δ ϭ 3.42 (s,
dienyl)-5-phenyl-6-β-(trans-phenylethenyl)-1-titana-2,9-dioxacyclo-
nona-3,7-diene (7c): 442 mg (0.65 mmol; 65%) from 234 mg of 3,
3
3
H, CH
3
), 4.48 (dd, J ϭ 5.62, 5.87 Hz, 1 H, 6-H), 4.84 (d, J ϭ
.62 Hz, 1 H, 5-H), 5.60 (d, J ϭ 5.62 Hz, 1 H, 7-H), 5.95 (d, J ϭ
3
3
2
64 mg of 4h and 238 mg of 6c; dark red air-sensitive needles from
Ϫ1
5.62 Hz, 1 H, 4-H), 6.01 (s, 5 H, Cp), 6.03 (s, 5 H, Cp), 6.17 (dd,
toluene; m.p. 114°C.Ϫ IR (KBr): ν˜ ϭ 3026 cm , 2960, 1600, 1251,
8
3
3
3
1
[30][33]: δ ϭ 3.21 (s, 3 H, CH
J ϭ 5.87, 15.62 Hz, 1 H, CHϭCHPh), 6.64 (d, J ϭ 15.62 Hz, 1
10. Ϫ H NMR (400 MHz, C
6
D
6
)
3
),
ar
13
3
H, CHϭCHPh), 6.68Ϫ7.82 (m, 19 H, H ). Ϫ C NMR (100.4
MHz, C ): δ ϭ 46.7, 48.1 (C-5, C-6), 55.2 (CH ), 105.7, 107.1
.23 (s, 3 H, CH
3
), 4.50 (dd, J ϭ 5.71, 5.71 Hz, 1 H, 6-H), 4.86
3
3
D
(d, J ϭ 5.86 Hz, 1 H, 5-H), 5.51 (d, J ϭ 5.71 Hz, 1 H, 7-H), 5.96
6
6
3
3
(C-4, C-7), 117.2 (Cp), 120.1, 122.2 (CHϭCHPh), 125.1, 125.7,
(d, J ϭ 5.86 Hz, 1 H, 4-H), 6.02 (s, 5 H, Cp), 6.04 (s, 5 H, Cp),
ar
.18 (dd, 3J ϭ 5.71, 15.86 Hz, 1 H, CHϭCHPh), 6.53 (d, J ϭ
3
126.4, 126.2, 131.6, 132.6, 134.1, 135.1, 135.8, 137.2, 138.1 (CH ),
6
1
ar
13
141.1, 142.1, 142.9, 145.4 (ipso-C), 159.7 (COCH
3
), 163.2, 163.3
5.86 Hz, 1 H, CHϭCHPh), 6.71Ϫ7.85 (m, 18 H, H ). Ϫ
): δ ϭ 46.5, 48.3 (C-5, C-6), 54.5, 54.8
), 113.5, 114.0 (C-4, C-7), 115.7 (Cp), 124.5, 127.2 (CHϭCH),
26.4, 126.7, 127.3, 127.7, 129.5, 132.7, 134.7, 135.5, 136.5, 137.5,
C
(
(
C-3, C-8). Ϫ MS (70 eV); m/z (%): 412 (9), 349 (22), 131 (55), 66
NMR (100.4 MHz, C
6 6
D
100). Ϫ C43
H
38
O
3
Ti (650.68): calcd. C 79.38, H 5.84; found C
(CH
3
7
8.49, H 6.05.
1
1
ar
38.1, 138.9 (CH ), 142.2, 142.5, 144.4, 145.2 (ipso-C), 156.5, 156.9
), 163.1, 163.5 (C-3, C-8). Ϫ MS (70 eV); m/z (%): 516
5
(
5,6-threo-3Z,7Z)-1,1-Bis(η -cyclopentadienyl)-3,5,8-triphenyl-
(
(
(
COCH
3
6
-β-(trans-phenylethenyl)-1-titana-2,9-dioxacyclonona-3,7-
ϩ
20), 381 (25), 264 (22) [C18
680.71): calcd. C 77.67, H 5.88; found C 76.50, H 5.75.
16 2 40 4
H O ], 165 (100). Ϫ C44H O Ti
diene (7g): 403 mg (0.65 mmol; 65%) from 234 mg of 3, 234 mg of
d and 208 mg of 4a (as the more reactive component); dark red
4
5
(
5,6-threo-3Z,7Z)-3,5-Bis(p-anisyl)-1,1-bis(η -cyclopenta- air-sensitive needles from toluene; m.p. 79°C. Ϫ IR (KBr): ν˜ ϭ
Ϫ1
1
dienyl)-8-phenyl-6-β-(trans-phenylethenyl)-1-titana-2,9-di- 3060Ϫ2800 cm , 1579, 1448, 1261, 1020, 807. Ϫ H NMR (400
[
30][33]
3
oxacyclonona-3,7-diene (7d): 462 mg (0.68 mmol; 68%) from 234
MHz, C
6
3
D
6
)
: δ ϭ 4.46 (dd, J ϭ 5.50, 5.50 Hz, 1 H, 6-H),
3
mg of 3, 234 mg of 4d and 268 mg of 6d; dark red air-sensitive 4.84 (d, J ϭ 5.50 Hz, 1 H, 5-H), 5.59 (d, J ϭ 5.50 Hz, 1 H, 7-
Eur. J. Inorg. Chem. 1998, 1253Ϫ1262
1259

F. Hampel, N. van Eikema Hommes, S. Hoops, F. Maaref, R. Schobert
H), 5.94 (s, 5 H, Cp), 5.98 (s, 5 H, Cp), 6.03 (d, J ϭ 5.50 Hz, 1 149°C. Ϫ IR (film): ν˜ ϭ 3095Ϫ2790 cmϪ1, 1680, 1590, 1510, 1250.
FULL PAPER
3
3
1
H, 4-H), 6.16 (dd, J ϭ 5.50, 15.40 Hz, 1 H, CHϭCHPh), 6.50 (d, Ϫ H NMR (400 MHz, CDCl
3
): δ ϭ 2.90 (m, 1 H, 5-H), 3.12 (m,
3
ar
J ϭ 15.40 Hz, 1 H, CHϭCHPh), 6.81Ϫ7.98 (m, 20 H, H ). Ϫ 1 H, 5-HЈ), 3.25 (m, 1 H, 4-H), 3.30 (m, 1 H, 2-H), 3.33 (m, 1 H,
13
6 6 3 3
C NMR (100.4 MHz, C D ): δ ϭ 45.5, 45.6 (C-5, C-6), 106.1, 2-HЈ), 3.67 (m, 1 H, 3-H), 3.79 (s, 3 H, CH ), 3.80 (s, 3 H, CH ),
3
1
1
1
06.7 (C-4, C-7), 116.1, 116.2 (Cp), 125.2, 125,9 (CHϭCHPh), 5.93 (dd, J ϭ 9.35, 15.40 Hz, 1 H, CHϭCHPh), 6.36 (d, 3J ϭ
ar
27.0, 127.9, 128.2, 128.9, 129.3, 130.1, 130.9, 132.1, 134.1, 137.2, 15.40 Hz, 1 H, CHPh), 6.82Ϫ7.82 (m, 18 H, H ). Ϫ MS (70 eV);
ar
ϩ
38.1, 139.1 (CH ), 141.1, 141.9, 143.9, 145.1 (ipso-C), 163.2, 164.0
Ti-
Ti ], 77 (100). Ϫ
Ti (620.65): calcd. C 81.28, H 5.80; found C 81.12, H
m/z (%): 504 (30) [M ], 359 (45), 331 (55), 281 (100), 145 (70). Ϫ
(504.63): calcd. C 80.95, H 6.35; found C 80.75, H 6.47.
(
C-3, C-8). Ϫ MS (70 eV); m/z (%): 450 (10), 386 (15) [Cp
2
34 32 4
C H O
ϩ
ϩ
OCPhCHϭCHPh ], 221 (45), 178 (55) [Cp
2
1
-(o,p-Dimethoxyphenyl)-3,6-diphenyl-4-β-(trans-phenyl-
ethenyl)hexan-1,6-dione (9e): According to general procedure D:
82 mg (0.56 mmol; 55%) from 680 mg of 7e; yellow needles from
42 36 2
C H O
5.69.
2
Ϫ1
4
. Synthesis of 9, 10, 11, 12, and 13. Ϫ General Procedure (C): cloroform; m.p. 145°C. Ϫ IR (film): ν˜ ϭ 3150Ϫ2800 cm , 1680,
1
Complex 5 or 7 (1 mmol) was dissolved in CH
of HCl in 5 ml of diethyl ether was added at Ϫ10°C and the mix-
ture was then stirred for 5 h, whereupon the colour turned from 3.33 (m, 1 H, 2-HЈ), 3.68 (m, 1 H, 3-H), 3.78 (s, 3 H, CH
2
Cl
2
(10 ml). 5 mmol 1600, 1255. Ϫ H NMR (400 MHz, CDCl
H), 3.14 (m, 1 H, 5-HЈ), 3.25 (m, 1 H, 4-H), 3.30 (m, 1 H, 2-H),
), 3.79
), 5.93 (dd, J ϭ 9.35, 15.40 Hz, 1 H, CHϭCHPh),
2 2
TiCl was removed by CC on silica gel 6.36 (d, J ϭ 15.40 Hz, 1 H, CHϭCHPh), 6.82Ϫ7.82 (m, 18 H,
3
): δ ϭ 2.92 (m, 1 H, 5-
3
3
dark red to bright red. The solvent and excess HCl were removed (s, 3 H, CH
3
3
at reduced pressure, Cp
CH Cl ). The eluate was concentrated and the products 9Ϫ13 were H ). Ϫ MS (70 eV); m/z (%): 504 (40) [M ], 390 (53), 354 (45),
separated by using preparative TLC (silica gel, CH Cl ). Separation 135 (100). Ϫ C34 (504.63): calcd. C 80.95, H 6.34; found C
ar
ϩ
(
2
2
2
2
32 4
H O
of the respective diastereomers was done by TLC (silica gel 60, 80.90, H 6.40.
diethyl ether/petroleum ether, 1:2) or by HPLC (silica gel 60, hep-
(
±)-2-Benzoyl-1-hydroxy-1-phenyl-3,4-bis-β-(trans-phenyl-
tane/ethyl acetate, 9:1). For analytical purposes samples were
recrystallized from chloroform or CH Cl /hexane, 3:1. Ϫ General
Procedure (D): Complex 7 or 5 (1 mmol) was dissolved in CH Cl
10 ml). At ambient temperature 5 ml of aqueous HCl (6%) was
added. After stirring this mixture for 3 h, the layers were separated,
the aqueous one was washed twice with 5 ml of CH Cl and the
combined organic extracts thus obtained were dried with sodium
[34]
ethenyl)cyclopentane (10a) : According to general procedure C:
97 mg (0.42 mmol: 42%) from 646 mg of 5d; white needles from
chloroform; m.p. 140°C. Ϫ IR (film): ν˜ ϭ 3090 cm , 2780, 1675,
590, 1515, 1250. Ϫ H NMR (400 MHz, CDCl ): δ ϭ 2.17 (dd,
3
J ϭ 5.50, J ϭ 14.30 Hz, 1 H, 5-H), 2.59 (dd, J ϭ 10.45 Hz, J ϭ
4.30 Hz, 1 H, 5-HЈ), 2.92 (m, 1 H, 3-H or 4-H), 3.39 (m, 1 H, 4-
H or 3-H), 4.18 (d, J ϭ 11.55 Hz, 1 H, 2-H), 5.04 (s, 1 H, OH),
.02 (dd, J ϭ 15.94 Hz and 8.79 Hz, 2 H, CHϭCHPh), 6.48 (d,
J ϭ 15.94 Hz, 2 H, CHϭCHPh), 6.91Ϫ7.68 (m, 20 H, H ). Ϫ
2
2
1
2
2
Ϫ1
(
1
1
3
2
3
2
2
2
1
3
2 2
sulphate. Separation of the products 9Ϫ13 and Cp TiCl was ac-
complished as described in General Procedure (C).
3
6
3
ar
ϩ
ϩ
1
,6-Diphenyl-3,4-bis-β-(trans-phenylethenyl)hexan-1,6-dione MS (70 eV); m/z (%): 470 (10) [M ], 452 (20) [M Ϫ H
2
O], 345 (20)
(470.62): calcd. C
ϩ
ϩ
(9a): According to general procedure D: 418 mg (0.89 mmol; 89%)
[M Ϫ PhCO], 105 (100) [PhCO ]. Ϫ C34
H
30
O
2
from 646 mg of 5d; yellow needles from chloroform; m.p. 140°C. 86.80, H 6.38; found C 86.81, H 6.35.
Ϫ1
1
Ϫ IR (film): ν˜ ϭ 3050 cm , 2980, 2960, 1680, 1650, 1490. Ϫ H
NMR (400 HMz, CDCl ): δ ϭ 3.09Ϫ3.27 (m, 6 H, 2-H, 3-H, 4-H,
Spiroketone 10b: According to general procedure C: 538 mg (1.22
mmol; 80%) from 944 mg of 5f as a 8:7:3:26:5:14:17:21 mixture of
3
3
3
5
1
-H), 6.16 (dd, J ϭ 15.62/8.97 Hz, 2 H, CHϭCHPh), 6.42 (d, J ϭ
8
stereoisomers; white needles from chloroform; separation of a
ar
13
5.62 Hz, 2 H, CHϭCHPh), 7.21Ϫ7.93 (m, 20 H, H ). Ϫ
): δ ϭ 42.2 (C-2, C-5), 43.0 (C-3, C-4),
24.0, 126.2 (CHϭCHPh), 128.5, 128.9, 132.9, 132.1, 137.0, 137.2
C
sample of the major diastereomer (26%) for analytical purposes by
NMR (100.4 MHz, CDCl
3
Ϫ1
TLC; m.p. 199°C. Ϫ IR (KBr): ν˜ ϭ 3429 cm , 1705, 1682, 1605.
1
1
Ϫ H NMR (400 MHz, CDCl
3
): δ ϭ 1.96 (s, 1 H, OH), 2.74 (d,
ar
(
(
(
CH ), 137.8, 138.2 (ipso-C), 198.8 (C-1, C-6). Ϫ MS (70 eV); m/z
%): 470 (7) [M ], 350 (80), 235 (92), 105 (100). Ϫ C34H O
30 2
470.62): calcd. C 86.80, H 6.38; found C 86.72, H 6.47.
3
2
2
J ϭ 8.0 Hz, J not observed, 2 H, 9-H), 2.80 (d, J ϭ 16.5 Hz, 1
H, 4-H), 3.26 (ddd, J ϭ 8.0, 8.0, 8.0 Hz, 1 H, 10-H), 3.98 (d, J ϭ
6.5 Hz, 1 H, 4-HЈ), 4.27 (d, J ϭ 13.5 Hz, 1 H, 12-H), 4.38 (dd,
ϩ
3
2
3
1
3
ar
1
,2-Bis[2Ј-(1Ј-oxoindanyl)]-1,2-diphenylethane (9b): According
to general procedure C: 90 mg (0.2 mmol; 13%) from 944 mg of 5f
as a separable 22:55:24 mixture of diastereomers; yellow needles 7.16 (m, 2 H, H ), 7.22 (m, 2 H, H ), 7.32 (m, 2 H, H ), 7.39 (m,
J ϭ 8.0, 13.5 Hz, 1 H, 11-H), 6.64 (m, 1 H, H ), 7.03 (m, 2 H,
ar
ar
ar
ar
H ), 7.07 (m, 2 H, H ), 7.11 (m, 2 H, H ), 7.14 (m, 1 H, H ),
ar
ar
ar
ar
ar
ar
from chloroform; a sample of the major isomer was separated by
1 H, H ), 7.50 (m, 1 H, H ), 7.52 (m, 1 H, H ), 7.68 (m, 1 H,
Ϫ1
1
ar
13
TLC; m.p. 200°C. Ϫ IR (film): ν˜ ϭ 1963 cm , 1714, 1694. Ϫ H H ). Ϫ C NMR (100.4 MHz, CDCl
): δ ϭ 31.4, 33.4 (C-4, C-
3
): δ ϭ 2.82 (dd, J ϭ 17.00, J ϭ 4.40 Hz, 9), 46.7 (C-11), 49.3 (C-10), 57.4 (C-12), 71.1 (C-5), 94.6 (C-6),
3
2
3
NMR (400 MHz, CDCl
2
3
2
(
4
4
2
2
H, CHHЈ), 3.45 (dd, J ϭ 17.00, J ϭ 8.00 Hz, 2 H, CHHЈ), 4.07 123.5, 124.4, 124.7, 125.9, 126.1, 126.4, 126.6, 127.0, 128.1, 128.2,
m, 2 H, CHCϭO), 4.28 (m, 2 H, 1-H, 2-H), 6.85 (t, J ϭ 7.70 Hz, 128.8, 129.0, 129.3, 134.7 (CH ), 137.8, 138.0, 139.6, 143.5, 144.7,
H, H ), 6.86 (t, J ϭ 7.70 Hz, 2 H, H ), 6.92 (d, J ϭ 7.70 Hz, 154.3 (C-2, C-3, C-7, C-8, 11-C, 12-C), 207.0 (C-1). Ϫ MS (70 eV);
H, H ), 7.24 (d, J ϭ 7.70 Hz, 2 H, H ), 7.28 (t, J ϭ 7.70 Hz, m/z (%): 442 (10) [M ], 424 (2) [M Ϫ H
3
ar
ar
3
ar
3
ar
3
ar
3
ϩ
ϩ
ϩ
2
O], 310 (15) [M
Ϫ
ar
3
ar
3
ϩ
H, H ), 7.44 (t, J ϭ 7.70 Hz, 2 H, H ), 7.73 (d, J ϭ 7.70 Hz,
C
9
H
8
O], 221 (100) [M/2 ]. Ϫ C32
26 2
H O (442.56): calcd. C 86.85,
ar
13
H, H ). Ϫ C NMR (100.4 MHz, CDCl ): δ ϭ 31.7 (CH ), 48.3 H 5.92; found C 86.77, H 5.87.
3 2
(
1
CHCϭO), 51.0 (C-1, C-2), 123.2, 126.1, 126.3, 127.0, 127.7, 129.2,
(
±)-(3,4-threo)-2-Acetyl-1-hydroxy-1-methyl-3,4-bis-o-(methyl-
ar
34.5 (CH ), 138.1, 140.5 (ipso-C), 154.3 [C(CϭO)CH], 209.8 (Cϭ
[34]
trans-cinnamoyl)cyclopentane (10c) : According to general pro-
cedure D: 31 mg (0.07 mmol; 45%) from 95 mg of 5g; white needles
): ν˜ ϭ 1697 cm
from chloroform; m.p. 101°C. Ϫ IR (CH Cl ,
2 2
660, 1618, 1342, 1300, 1178, 1155. Ϫ H NMR (400 MHz,
): δ ϭ 1.58 (s, 3 H, 1-CH ), 1.76 (s, 1 H, OH), 1.93 [s, 3 H,
ϩ
ϩ
9 8
O). Ϫ MS (70 eV); m/z (%): 442 (6) [M ], 310 (68) [M Ϫ C H O],
2
C H O
32 26 2
ϩ
ϩ
ϩ
21 (100) [M/2 ], 132 (20) [C
9 8 2
H O ], 91 (48) [PhCH ]. Ϫ
Ϫ1
(442.56): calcd. C 86.85, H 5.92; found C 86.77, H 5.82.
1
1
1
,3-Bis(p-anisyl)-6-phenyl-4-β-(trans-phenylethenyl)hexan- CDCl
,6-dione (9d): According to general procedure D: 281 mg (0.56 (CO)CH
mmol; 56%) from 680 mg 7d; yellow needles from chloroform; m.p.
3
3
3
2
1
3
], 2.27 (dd, J ϭ 14.3, J ϭ 6.5 Hz, 1 H, 5-H), 2.43 (dd,
2
3
J ϭ 14.3, J ϭ 11.0 Hz, 1 H, 5-HЈ), 3.59 (m, 1 H, 4-H), 3.71 (s, 3
Eur. J. Inorg. Chem. 1998, 1253Ϫ1262
1
260

Novel Nine-Membered Titanaheterocycles
H, OCH ), 3.72 (s, 3 H, OCH ), 3.72 (hidden, 1 H, 3-H), 4.00 (d, H, 2-H), 4.91 (s, 1 H, OH), 6.04 (dd, J ϭ 9.35, 15.95 Hz, 1 H,
FULL PAPER
3
3
3
3
3
3
J ϭ 11.50 Hz, 1 H, 2-H), 5.74 (d, J ϭ 15.00 Hz, 2 H, CHϭ CHϭCHPh), 6.44 (d, J ϭ 15.95 Hz, 1 H, CHϭCHPh), 6.90Ϫ7.80
ar
ar
ar
ar
ϩ
ϩ
CHCO), 7.11 (m, 1 H, H ), 7.15 (m, 1 H, H ), 7.18 (m, 1 H, H ), (m, 18 H, H ). Ϫ MS (70 eV); m/z (%): 504 (6) [M ], 486 (10) [M
7
1
ar
ar
ar
.35 (m, 1 H, H ), 7.38 (m, 1 H, H ), 7.43 (m, 1 H, H ), 7.55 (m, Ϫ H
H, H ), 7.60 (m, 1 H, H ), 7.87 (d, J ϭ 15.00 Hz, 1 H, CHϭ 80.78, H 6.29.
2
O]. Ϫ C34
H
32
O
4
(504.63): calcld. C 80.93, H 6.39; found C
ar
ar
3
3
13
CHCO), 7.88 (d, J ϭ 15.00 Hz, 1 H, CHϭCHCO). Ϫ C NMR
1
-Benzoyl-2-(o,p-dimethoxyphenyl)-4-phenyl-5-β-(trans-
phenylethenyl)cyclopent-1-ene (12e): According to general pro-
cedure C: 170 mg (0.35 mmol; 35%) from 681 mg of 7e; white
(100.4 MHz, CDCl
3
): 28.1 [(CO)CH
3
], 33.1 (1-C), 47.8 (C-4), 48.2
), 53.5 (C-3), 66.0 (C-2), 80.1 (C-1), 118.9,
19.9 (CHϭCHCO), 126.2, 126.7, 127.3, 127.4, 127.8, 128.1, 130.3,
30.7 (8 C, CH ), 133.5, 134.5 (CCHϭCHCϭO), 134.9, 138.9 (3-
(C-5), 51.4, 51.5 (OCH
3
1
1
Ϫ1
needles from chloroform. Ϫ IR (film): ν˜ ϭ 2962 cm , 1721, 1677,
ar
1
1
604, 1450, 1261. Ϫ H NMR (400 MHz, C
6
D
6
): δ ϭ 3.00 (m, 1
), 3.72 (s, 3 H, CH ),
.26 (dd, J ϭ 6.10, 9.36 Hz, 1 H, 5-H), 6.12 (dd, J ϭ 9.36, 15.95
C, 4-C), 141.3, 142.1 (CHϭCHCO), 166.5, 166.9 (COO), 212.1 (2-
C). Ϫ MS (70 eV); m/z (%): 462 (9) [M ], 369 (9), 337 (6), 277 (51),
2
H, 4-H), 3.62 (m, 2 H, 3-H), 3.63 (s, 3 H, CH
3
3
ϩ
3
3
4
ϩ
3
32 (19) [C14
H
16
O
], 199 (68), 171 (75), 157 (99), 129 (94), 115
30 6
H O (462.54): calcd. C 72.71, H 6.54; found
3
Hz, 1 H, CHϭCHPh), 6.42 (d, J ϭ 15.95 Hz, 1 H, CHϭCHPh),
.02Ϫ7.92 (m, 18 H, H ). Ϫ MS (70 eV); m/z (%): 486 (28) [M ],
55 (15) [M Ϫ OCH ], 381 (28) [M Ϫ PhCO], 149 (100). Ϫ
3
(70), 43 (100). Ϫ C28
ar
ϩ
7
4
C 72.82, H 6.59.
ϩ
ϩ
(
±)-1,4-Bis(p-anisyl)-2-benzoyl-1-hydroxy-3-β-(trans-phen-
34 30 3
C H O (486.62): calcd. C 83.92, H 6.21; found C 83.83, H 6.18.
[34]
ylethenyl)cyclopentane (10d) : According to general procedure D:
2 mg (0.1 mmol; 10%) from 680 mg of 7d; white needles from
chloroform. Ϫ IR (film): ν˜ ϭ 3059Ϫ2805 cm , 1675, 1600, 1510,
450, 1260. Ϫ H NMR (400 MHz, CDCl
.50 Hz, J ϭ 14.30 Hz, 1 H, 5-H), 2.77 (dd, J ϭ 11.00 Hz, J ϭ
4.30 Hz, 1 H, 5-HЈ), 3.25 (m, 1 H, 3-H), 3.60 (m, 1 H, 4-H), 3.76
s, 3 H, CH
H), 4.93 (s, 1 H, OH), 5.96 (dd, J ϭ 9.35, 15.95 Hz, 1 H, CHϭ
2
-(p-Anisyl)-1-benzoyl-4-phenyl-5-β-(trans-phenylethenyl)-
cyclopent-1-ene (12f): According to general procedure C: 173 mg
0.38 mmol; 38%) from 650 mg of 7f; white needles from cloroform.
5
Ϫ1
(
1
3
1
5
1
3
): δ ϭ 2.33 (dd, J ϭ
Ϫ1
Ϫ IR (film): ν˜ ϭ 3090Ϫ2800 cm , 1660, 1600, 1510, 1450, 1260.
Ϫ H NMR (400 MHz, CDCl ): δ ϭ 3.01 (m, 1 H, 4-H), 3.45 (s,
3
3
2
3
2
1
3
H, CH
3
), 3.63 (m, 2 H, 3-H), 4.24 (dd, J ϭ 6.05, 9.35 Hz, 1 H,
-H), 6.03 (dd, J ϭ 9.35, 15.95 Hz, 1 H, CHϭCHPh), 6.33 (d,
J ϭ 15.95 Hz, 1 H, CHϭCHPh), 6.91Ϫ7.79 (m, 19 H, H ). Ϫ
3
(
3
), 3.80 (s, 3 H, CH
3
), 4.37 (d, J ϭ 12.09 Hz, 1 H, 2-
3
5
3
3
ar
3
CHPh), 6.20 (d, J ϭ 15.95 Hz, 1 H, CHPh), 6.45Ϫ7.82 (m, 18 H,
ϩ
MS (70 eV); m/z (%): 456 (72) [M ], 365 (20), 351 (100) [M Ϫ
ar
ϩ
ϩ
H ). Ϫ MS (70 eV); m/z (%): 504 (4) [M ], 486 (10) [M Ϫ H
89 (40), 269 (100), 135 (20). Ϫ C34 (504.63): calcd. C 80.93,
H 6.39; found C 80.85, H 6.44.
2
O],
C
6
H
5 28 2
CO], 105 (75). Ϫ C33H O (456.59): calcd. C 86.40, H 6.14;
3
32 4
H O
found C 86.47, H 6.11.
1
-(o,p-Dimethoxybenzoyl)-2,5-diphenyl-4-β-(trans-phenyl-
ethenyl)cyclopent-1-ene (13e): According to general procedure C:
22 mg (0.25 mmol; 25%) from 681 mg of 7e; white needles from
(
±)-2-Benzoyl-1-(o,p-dimethoxyphenyl)-1-hydroxy-4-phenyl-3-β-
[34]
(
trans-phenylethenyl)cyclopentane (10e) : According to general
procedure D: 57 mg (0.11 mmol; 11%) from 680 mg of 7e; white
needles from chloroform. Ϫ IR (film): ν˜ ϭ 3059Ϫ2850 cm , 1676,
598, 1512, 1450, 1260, 1027. Ϫ H NMR (400 MHz, CDCl
.30 (dd, J ϭ 5.50, J ϭ 14.30 Hz, 1 H, 5-H), 2.75 (dd, J ϭ 11.10,
J ϭ 14.30 Hz, 1 H, 5-HЈ), 3.26 (m, 1 H, 3-H), 3.52 (m, 1 H, 4-H),
3 3
.78 (s, 3 H, CH ), 3.80 (s, 3 H, CH ), 4.39 (d, J ϭ 12.11 Hz, 1
H, 2-H), 4.90 (s, 1 H, OH), 6.04 (dd, J ϭ 9.35, 15.95 Hz,1 H,
1
Ϫ1
chloroform. Ϫ IR (film): ν˜ ϭ 2925 cm , 2854, 1736, 1677, 1601,
Ϫ1
1
1
450, 1261. Ϫ H NMR (400 MHz, C
6
D
6
): δ ϭ 2.91 (m, 1 H, 4-
), 4.45
d, J ϭ 7.82 Hz, 1 H, 5-H), 6.14 (dd, J ϭ 9.35, 15.95 Hz, 1 H,
1
1
3
): δ ϭ
H), 3.39 (s, 3 H, CH ), 3.47 (m, 2 H, 3-H), 3.75 (s, 3 H, CH
3
3
3
2
3
2
3
3
(
2
3
CHϭCHPh), 6.45 (d, J ϭ 15.95 Hz, 1 H, CHϭCHPh), 7.05Ϫ7.92
3
3
ar
ϩ
(
m, 18 H, H ). Ϫ MS (70 eV); m/z (%): 486 (16) [M ], 322 (16)
3
ϩ
[
M
6 3 3 2 30 3
Ϫ C H (OCH ) CO], 280 (45), 149 (100).Ϫ C34H O
3
CHϭCHPh), 6.44 (d, J ϭ 15.95 Hz, 1 H, CHϭCHPh), 6.90Ϫ7.80
(
486.62): calcd. C 83.92, H 6.21; found C 83.81, H 6.30.
ar
ϩ
ϩ
(
m, 18 H, H ). Ϫ MS (70 eV); m/z (%): 504 (6) [M ], 486 (10) [M
Ϫ H O], 381 (100), 135 (70). Ϫ C34 (504.63): calcd. C 80.93,
H 6.39; found C 80.87, H 6.40.
2
H
32
O
4
Ab initio Calculations: The ab initio and density functional calcu-
lations were performed with the Gaussian 94 suite of programs.
[
19]
Structures were optimzed with no constraints other than symmetry
3
-(p-Anisyl)-1-hydroxy-2-(p-methoxybenzoyl)-1-phenyl-4-β-
[20]
at the B3LYP/SVp level, i.e. using the B3LYP
density functional
[34]
(
trans-phenylethenyl)cyclopentane (11d) : According to general
procedure D: 35 mg (0.07 mmol; 7%) from 680 mg of 7d; white
needles from chloroform. Ϫ IR (film): ν˜ ϭ 3060Ϫ2800 cm , 1690,
510, 1500, 1450, 1260, 1100. Ϫ H NMR (400 MHz, CDCl
.30 (dd, J ϭ 5.50, J ϭ 14.30 Hz, 1 H, 5-H), 2.78 (dd, J ϭ 11.00,
J ϭ 14.30 Hz, 1 H, 5-HЈ), 2.96 (m, 1 H, 4-H), 3.63 (s, 3 H, CH
.67 (s, 3 H, CH ), 3.80 (m, 1 H, 3-H), 4.32 (d, J ϭ 11.60 Hz, 1
H, 2-H), 4.95 (s, 1 H, OH), 5.96 (dd, J ϭ 9.35, 15.95 Hz, 1 H,
and a split valence basis set[ , augmented with standard polariz-
21]
ation functions on the non-hydrogen atoms.[ Vibrational fre-
22]
Ϫ1
[
23]
quencies and zero-point energy corrections, scaled by 0.98 , were
computed at this level. Refinement of the structures was performed
at the MP2/SVp level. Energy calculations were done at MP2/TZ2p
level (i.e., using a triple-zeta basis set[ and split polarization func-
tions).
1
1
3
): δ ϭ
3
2
3
2
2
3
),
21]
3
3
3
3
3
CHϭCHPh), 6.20 (d, J ϭ 15.95 Hz, 1 H, CHPh), 6.45Ϫ7.82 (m,
ar
ϩ
ϩ
[1]
[1a]
1
H
6
8 H, H ). Ϫ MS (70 eV); m/z (%): 504 (5) [M ], 486 (9) [M
O], 360 (35), 269 (100). Ϫ C34 (504.63): calcd. C 80.93, H
.39; found C 80.85, H 6.34.
-
For 4-membered titanaheterocycles see:
Chem. Soc., Dalton Trans. 1997, 1991Ϫ2001. Ϫ
haus, J. Oster, J. Sang, I. Strauß, T. Wagner, Synlett 1997
R. Beckhaus, J.
[1b]
R. Beck-
S. C. Ho, S. Hentges, R. H. Grubbs, Organomet-
2
32 4
H O
[1c]
2
41Ϫ249. Ϫ
allics 1988, 7, 780Ϫ782. Ϫ
109, 694Ϫ722; Angew. Chem. Int. Ed. Engl. 1997, 36, 686Ϫ713.
[1d]
R. Beckhaus, Angew. Chem. 1997,
2
-(o,p-Dimethoxybenzoyl)-1-hydroxy-1,3-diphenyl-4-β-(trans-
[34]
phenylethenyl)cyclopentane (11e) : According to general pro-
cedure D: 40 mg (0.08 mmol; 8%) from 680 mg of 7e; white needles
from chloroform. Ϫ IR (film): ν˜ ϭ 3059Ϫ2850 cm , 2850, 1679,
598, 1512, 1450, 1260, 1027. Ϫ H NMR (400 MHz, CDCl
.27 (dd, J ϭ 5.50, J ϭ 14.30 Hz, 1 H, 5-H), 2.75 (dd, J ϭ 11.01,
[1e]
Ϫ
K. M. Doxsee, J. J. J. Juliette, J. K. M. Mauser, K. Zien-
[1f]
tara, Organometallics 1993, 12, 4742Ϫ4744. Ϫ
D. Seyferth,
Ϫ1
T. Wang, W. M. Davis, Organometallics 1994, 13, 4134Ϫ4136.
Ϫ [ R. G o´ mez, R. Duchateau, A. N. Chernega, J. H. Teuben,
F. T. Edelmann, M. L. H. Green, J. Organomet. Chem. 1995,
1g]
1
1
3
): δ ϭ
3
2
3
2
4
91, 153Ϫ158.
2
J ϭ 14.30 Hz, 1 H, 5-HЈ), 3.02 (m, 1 H, 4-H), 3.76 (s, 3 H, CH
.78 (s, 3 H, CH
3
),
[2]
[1d]
[2a]
For 6-membered titanaheterocycles see ref.
and:
R. Beck-
3
3
3
), 3.82 (m, 1 H, 3-H), 4.37 (d, J ϭ 12.11 Hz, 1
haus, T. Wagner, C. Zimmermann, E. Herdtweck, J. Organomet.
Eur. J. Inorg. Chem. 1998, 1253Ϫ1262
1261

F. Hampel, N. van Eikema Hommes, S. Hoops, F. Maaref, R. Schobert
FULL PAPER
Chem. 1993, 460, 181Ϫ189. Ϫ [ N. M. Kablaoui, F. A. Hicks,
2b]
Am. Chem. Soc. 1989, 111, 8751Ϫ8753 and Organometallics
1992, 11, 761Ϫ777.
S. L. Buchwald, J. Am. Chem. Soc. 1997, 119, 4424Ϫ4431. Ϫ
[
2c]
[18]
P. Veya, C. Floriani, A. ChiesiϪVilla, C. Rizzoli, Organome-
B. Demerseman, G. Bouquet, M. Bigorgne, J. Organomet.
[2d]
tallics 1993, 12, 4892Ϫ4898. Ϫ
K. Mashima, K. Jyodoi, A.
Chem. 1975, 101, C24ϪC26.
[19]
Ohyoshi, H. Takaya, J. Chem. Soc., Chem. Commun. 1986,
M. J. Frisch, G. W. Trucks, H. B. Schlegel, P. M. W. Gill, B. G.
Johnson, M. A. Robb, J. R. Cheeseman, T. Keith, G. A. Peters-
son, J. A. Montgomery, K. Raghavachari, M. A. Al-Laham, V.
G. Zakrzewski, J. V. Ortiz, J. B. Foresman, J. Cioslowski, B. B.
Stefanov, A. Nanayakkara, M. Challacombe, C. Y. Peng, P. Y.
Ayala, W. Chen, M. W. Wong, J. L. Andres, E. S. Replogle, R.
Gomperts, R. L. Martin, D. J. Fox, J. S. Binkley, D. J. Defrees,
J. Baker, J. P. Stewart, M. Head-Gordon, C. Gonzalez, J. A.
Pople, Gaussian 94 Revision E.2, Gaussian, Inc., Pittsburgh
PA, 1995.
20] [20a]
[
2e]
1145Ϫ1146 and Organometallics 1987, 6, 885Ϫ887. Ϫ
K. M.
Doxsee, J. J. J. Juliette, T. J. R. Weakley, K. Zientara, Inorg.
[
2f]
Chim. Acta 1994, 222, 305Ϫ313. Ϫ
ahi, H. Hope, J. Am. Chem. Soc. 1991, 113, 8889Ϫ8898. Ϫ
K. M. Doxsee, J. B. Far-
[
2g]
K. Mashima, H. Haraguchi, A. Ohyoshi, N. Sakai, H. Takaya,
Organometallics 1991, 10, 2731Ϫ2736.
A. V. Firth, D. W. Stephan, Organometallics 1997, 16,
[
[
[
3]
4]
5]
6]
2
183Ϫ2188.
R. Steudel, M. Kustos, V. Münchow, U. Westphal, Chem. Ber.
997, 130, 757Ϫ764.
[
1
A. D. Becke, J. Chem. Phys. 1993, 98, 5648Ϫ5652, and ref-
[20b]
erences therein. Ϫ
P. J. Stevens, F. J. Devlin, C. F. Chablow-
T. E. Waldman, A. M. Wilson, A. L. Rheingold, E. Melendez,
R. D. Ernst, Organometallics 1992, 11, 3201Ϫ3209.
K. Andrä, J. Organomet. Chem. 1968, 11, 567Ϫ570.
ski, M. J. Frisch, J. Phys. Chem. 1994, 98, 11623Ϫ11627.
A. Schaefer, H. Horn, R. Ahlrichs, J. Chem. Phys. 1992, 97,
2571Ϫ2577.
[
[
[
21]
22]
23]
[
[
7] [7a]
M. Pasquali, C. Floriani, A. Chiesi-Villa, C. Guastini, Inorg.
[
7b]
S. Huzinaga (Ed.), Gaussian Basis Sets for Molecular Calcu-
lations, Elsevier, Amsterdam, 1984.
C. W. Bauschlicher, Jr., H. Partridge, J. Chem. Phys. 1995,
103, 1788Ϫ1791.
K. R. Bharucha, J. Chem. Soc. 1956, 2446Ϫ2447.
R. Cornubert, C. H. R. Borrel, Bull. Soc. Chim. Fr. 1929, 45,
1148Ϫ1161.
Chem. 1981, 20, 349Ϫ355. Ϫ
J. Scholz, M. Dlikan, K. Thi-
ele, J. Prakt. Chem. 1988, 330, 808.
[
8]
[8a]
For 5-membered titanaheterocycles see:
G. Doyle, R. S. To-
[8b]
bias, Inorg. Chem. 1968, 7, 2484Ϫ2488. Ϫ
C. Floriani, G.
[
[
24]
25]
Fachinetti, J. Chem. Soc., Chem. Commun. 1972, 790Ϫ791. Ϫ
[
8c]
M. Pasquali, C. Floriani, A. ChiesiϪVilla, C. Guastini, J.
[
8d]
Am. Chem. Soc. 1979, 101, 4740Ϫ4742. Ϫ
J. Scholz, M.
N. M. Kablaoui, F. A.
[
[
26]
27]
A. Hassner, T. C. Mead, Tetrahedron 1964, 20, 2201Ϫ2210.
O. Isler, H. Gutmann, M. Montavon, R. Rüegg, P. Zeller, Helv.
Chim. Acta 1957, 40, 1242Ϫ1249.
Dlikan, D. Ströhl, A. Dietrich, H. Schumann, K. H. Thiele,
[
8e]
Chem. Ber. 1990, 123, 2279Ϫ2285. Ϫ
Hicks, S. L. Buchwald, J. Am. Chem. Soc. 1996, 118,
[
28] [28a]
[
8f]
F. Ramirez, S. Dershowitz, J. Org. Chem. 1957, 22, 41Ϫ45.
5818Ϫ5819. Ϫ
R. Beckhaus, J. Oster, R. Kempe, A. Span-
[28b]
Ϫ
A. Groß, Ph. D. Thesis, University of Erlangen-
nenberg, Angew. Chem. 1996, 108, 1636Ϫ1638; Angew. Chem.
[
8g]
Nürnberg, 1994, p. 75.
Int. Ed. Engl. 1996, 35, 1565Ϫ1567. Ϫ
son, R. F. Jordan, Organometallics 1997, 16, 1392Ϫ1400. Ϫ
S. Gambarotta, C. Floriani, A, Chiesi-Villa, C. Guastini, J. Am.
B. Tsuie, D. C. Swen-
[
[
29]
[8h]
S. Dürr, Ph. D. Thesis, University of Erlangen-Nürnberg 1997,
p. 102.
30] 3
[8i]
J coupling constants between 5-H und 6-H in compounds 5
Chem. Soc. 1982, 104, 1918Ϫ1924. Ϫ
P. Binger, F. Sand-
und 7 are below 1 Hz and not clearly determinable (broad sig-
nals for 5-H and 6-H).
31]
meyer, C. Krüger, Organometallics 1995, 14, 2969Ϫ2976.
V. B. Shur, V. V. Burlakov, A. I. Yanovsky, P. V. Petrovsky, Y. T.
Struchkov, M. E. VolЈpin, J. Organomet. Chem. 1985, 297,
[
9]
[
Crystallographic data (excluding structure factors) for the struc-
ture reported in this paper have been deposited with the Cam-
bridge Crystallographic Data Centre (CCDC-100857). Copies
of the data can be obtained free of charge on application to
CCDC, 12 Union Road, Cambridge CB2 1EZ, UK (fax: int.
code ϩ 44-1223/336-033; e-mail: deposit@ccdc.cam.ac.uk).
The moderate R value is due to the fact, that 5a is a poorly
reflecting compound. Unfortunately, it was only possible to
solve the strong disorder of the toluene solvent molecules in a
very rough way.
51Ϫ59.
[
10]
C. Lefeber, A. Ohff, A. Tillack, W. Baumann, R. Kempe, V. V.
Burlakov, U. Rosenthal, H. Görls, J. Organomet. Chem. 1995,
5
01, 179Ϫ188.
[
[
11]
12]
S. Dürr, U. Höhlein, R. Schobert, J. Organomet. Chem. 1993,
58, 89Ϫ96.
For other 7-membered titanaheterocycles see:
thaler, A. Hafner, M. Riediker, Pure Appl. Chem. 1990, 62Ϫ63.
[32]
4
[12a]
R. O. Du-
[
12b]
Ϫ
R. O. Duthaler, A. Hafner, M. Riediker, “Asymmetric
[33]
[34]
Assignment of NMR signals by comparison with spectra of
similarly substituted “symmetric” derivatives of type 5.
Characterization of 10/11 by comparison with spectral data of
analogous “symmetric” alcohols. The stereochemistry of the
hydroxy function of 10 was determined by comparing NMR
CϪC bond formation with Ti-, Zr-, and Hf-carbohydrate com-
plexes” in Organic Synthesis via Organometallics (Eds.: K. H.
Dötz, R. W. Hoffmann), Vieweg, Braunschweig, 1991, p.
2
85Ϫ309.
[
13]
14]
K. Bergemann, M. Kustos, P. Krüger, R. Steudel, Angew. Chem.
995, 107, 1481Ϫ1483; Angew. Chem. Int. Ed. Engl. 1995, 34,
and IR data of similar compounds characterized by other
1
1
[34a]
groups, as for example:
H. Olivier, Y. Chauvin, L. Saussine,
330Ϫ1331.
[34b]
Tetrahedron 1989, 45, 165Ϫ169. Ϫ
K. Takaki, F. Beppu, I.
[34c]
[
[
R. Schobert, F. Maaref, S. Dürr, Synlett 1995, 83Ϫ84.
Nakagawa, Y. Fujiwara, Chem. Lett. 1992, 535Ϫ538. Ϫ
K.
15] [15a]
S. Fokken, T. P. Spaniol, J. Okuda, F. G. Sernetz, R.
Takaki, F. Beppu, S. Tanaka, Y. Tsubaki, T. Jintoku, Y. Fuji-
[
15b]
[34d]
Mülhaupt, Organometallics 1997, 16, 4240Ϫ4242. Ϫ
S.
wara, J. Chem. Soc., Chem. Commun. 1990, 516Ϫ517. Ϫ
Fokken, Ph. D. Thesis, University of Marburg, 1997.
K. Takaki, K. Nagase, F. Beppu, Y. Fujiwara, Chem. Lett. 1991,
[
[
16]
17]
[34e]
For a brief note lacking any further data see: J. M. Davis, R. J.
Whitby, A. Jaxa-Chamiec, J. Chem. Soc. Chem. Commun.
1665Ϫ1668. Ϫ
S. Falicki, H. Alper, Organometallics 1988,
[
34f]
7, 2548Ϫ2552. Ϫ
F. Fournier, J. Berthelot, J.-J. Basselier,
1991, 1743Ϫ1745.
Tetrahedron 1985, 41, 5667Ϫ5676.
M. J. Carney, P. J. Walsh, F. J. Hollander, R. G. Bergman, J.
[98077]
1262
Eur. J. Inorg. Chem. 1998, 1253Ϫ1262