Tetracyclic arenes by benzannulation of tricyclic carbene complexes of chromium with alkynes: Chemo-, regio-, and stereoselectivity

Article abstract of DOI:10.1002/(SICI)1521-3765(19980904)4:9<1843::AID-CHEM1843>3.0.CO;2-A

The tricarbonyl chromium complexes 7-9 and the tetracyclic arenes 11-13 were synthesized from 1-hexyne and the tricyclic chromium carbene complexes 3-5, which are derived from diazo precursors. The nonplanar dibenzocycloheptenylidene complex 4 afforded the benzannulation product S(p)M(h)/R(p)P(h)-8 stereoselectively, as established by NMR spectra and an X-ray crystal structure analysis. The benzannulation failed with the carbene complexes 1 and 2, presumably due to their reduced propensity for decarbonylation. Upon reaction with 1-hexyne, carbene complex 21, bearing two electronically different arene substituents, revealed only a low regioselectivity (1.6:1) in favour of chromium complex 22, which results from the annulation of the less electron-rich arene ring.

Full text of DOI:10.1002/(SICI)1521-3765(19980904)4:9<1843::AID-CHEM1843>3.0.CO;2-A

FULL PAPER
Tetracyclic Arenes by Benzannulation of Tricyclic Carbene Complexes of
Chromium with Alkynes: Chemo-, Regio-, and Stereoselectivity**
Jürgen Pfeiffer, Martin Nieger, and Karl Heinz Dötz*
Dedicated to Professsor Wolfgang Steglich on the occasion of his 65th birthday
Abstract: The tricarbonyl chromium complexes 7 ± 9 and the tetracyclic arenes 11 ±
1
3
3 were synthesized from 1-hexyne and the tricyclic chromium carbene complexes
± 5, which are derived from diazo precursors. The nonplanar dibenzocyclohepten-
ylidene complex 4 afforded the benzannulation product S M /R P -8 stereoselec-
p
h
p
h
Keywords: arenes ´ benzannulation
carbenes chromium
helical structures
tively, as established by NMR spectra and an X-ray crystal structure analysis. The
benzannulation failed with the carbene complexes 1 and 2, presumably due to their
reduced propensity for decarbonylation. Upon reaction with 1-hexyne, carbene
complex 21, bearing two electronically different arene substituents, revealed only a
low regioselectivity (1.6:1) in favour of chromium complex 22, which results from the
annulation of the less electron-rich arene ring.
´
´
´
Introduction
Fischer-type carbene complexes[1] have become valuable tools
for stereoselective carbon ± carbon bond formation within the
[
2]
last three decades. One of the most important synthetic
applications is the reaction of alkenyl- or aryl-substituted
alkoxycarbene complexes of chromium with alkynes, which
results in the formation of densely functionalized phenols or
naphthohydroquinones, respectively, by sequential coupling
of the alkyne, the carbene and one carbonyl ligand at a
[
3]
Cr(CO) template (Figure 1). This formal [3‡2‡1] cyclo-
3
addition proceeds with considerable regioselectivity in case of
alkyne substituents of distinctly different size.
[
4, 5]
Generally,
the arene formation is the major reaction path; however,
depending both on the substrates and the reaction conditions,
other cycloaddition products have been observed as well.[
The synthetic potential of the benzannulation reaction has
6]
Figure 1. Mechanism of the benzannulation reaction.
[
*] Prof. Dr. K. H. Dötz, Dr. J. Pfeiffer[‡]
Kekul e -Institut für Organische Chemie und Biochemie der
Universität Bonn
Gerhard-Domagk-Str. 1, D-53121 Bonn (Germany)
Fax: (‡49)228-73-5813
been demonstrated in the synthesis of various naturally
[7]
occuring compounds like vitamins of the E and K series,
E-mail: doetz@uni-bonn.de
[8]
[9]
antibiotics like deoxyfrenolicin, various daunomycinones
Dr. M. Nieger
[10]
Kinetic studies[11] indicate that the
and fredericamycin.
Institut für Anorganische Chemie der Universität Bonn (Germany)
benzannulation reaction starts with a reversible decarbon-
ylation that is followed by coordination of the alkyne to form
‡
[
] Present address
Institut für Anorganische Chemie der Technischen Universität Wien
a tetracarbonyl alkynecarbene complex A as the first
(Austria)
intermediate.[
12, 13]
Further support for the mechanism has
[
**] Reactions of Complex Ligands, Part 82. For Part 81, see J. Pfeiffer, M.
Nieger, K. H. Dötz, Eur. J. Org. Chem. 1998, 1, 1011.
been provided by isolation and structural characterization of
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K. H. Dötz et al.
FULL PAPER
presumed intermediates relevant to B[14] and C,[15] as well as
[
16]
by extended Hückel molecular orbital (EHMO)
quantum chemical calculations.
and
[
17, 18]
We recently reported
the synthesis and first benzannulation reactions of tricyclic
carbene complexes of chromium derived from diazo precur-
[
19]
sors.
We now present a full account of the regio- and
stereochemical implications, as well as of the chemoselectivity
of this type of reaction.
Results and Discussion
Reactions with 1-hexyne: The chromium carbene complexes
± 6[ derived from diazo precursors were treated with 1-
19]
1
hexyne (4 equiv) in tert-butyl methyl ether at room temper-
ature (reaction of 3 required warming to 408C). After
consumption of the starting compounds, silylation with
NEt /tert-butyldimethylsilyl chloride (TBDMSCl) and col-
3
umn chromatographic workup, the tricarbonyl chromium
complexes 7 ± 10 and the tetracyclic arenes 11 ± 13 were
obtained in good overall yields with complete regioselectivity
(Scheme 1, Table 1). Surprisingly, no benzannulation reaction
products could be obtained from the reactions of the carbene
complexes 1 and 2 under various reaction conditions. Instead,
a 78% yield of the formal carbene dimer 9,9'-[bis-(9H)-
fluorenylidene] (14) (see Scheme 2), which results from
Scheme 1. Reactions of the carbene complexes 1 ± 6 with 1-hexyne.
Reagents and conditions: a) 1-hexyne (4 equiv), tBuOMe, 208C (408C in
case of 3), 2 h; b) TBDMSCl (4 equiv), NEt (4 equiv), 208C, 2 h.
3
[
19]
thermal decomposition of carbene complex 1, was isolated,
while reaction of 2 only gave a complex reaction mixture.[
20]
Molecular structure of the tricarbonyl chromium complexes 8
and 9 in solution: Compounds 8 and 9, obtained from the
benzannulation reactions of the carbene complexes 4 and 5,
respectively, with 1-hexyne, contain a plane of chirality and
Table 1. Products from the reactions of carbene complexes 1 ± 6 with 1-
hexyne.
Products
Yield [%]
78
S [%][a]
[
21]
are known to adopt a helical conformation. As a result, two
diastereomers may be formed in each case. For the tricarbonyl
complex 9, containing a CH �CH bridge, a temperature
1
2
3
14
[
b]
7
1
8
9
26
42
55
27
68
2
2
1
dependence of the NMR spectra was observed that can be
rationalized in terms of a conformational flexibility of the
4
5
55
53[
c]
1
3
12
< 5
tetracyclic carbon skeleton (Figure 2). The C NMR spec-
trum of 9 measured at 253 K showed all expected resonances
as sharp signals. Warming to 298 K led to broadening of some
signals, for example, the resonance of the carbonyl groups;
1
10
3
26
62
6
62
[a] Sum of all benzannulation products. [b] Only an unseparable reaction
mixture was obtained. [c] Without 12.
moreover, several signals of the arene carbon atoms coordi-
Abstract in German: Die aus Diazovorstufen erhaltenen
Carbenkomplexe des Chroms 3 ± 5 reagieren mit 1-Hexin
unter Benzanellierung zu den tetracyclischen Tricarbonyl-
chromkomplexen 7 ± 9 und den tetracyclischen Arenen 11 ± 13.
Anhand der Temperaturabhängigkeit der NMR-Spektren so-
wie durch eine Röntgenstrukturanalyse konnte die stereoselek-
tive Bildung von S M /R P -8 aus 4 nachgewiesen werden.
Keine Benzanellierung gehen dagegen die Carbenkomplexe 1
und 2 mit 1-Hexin ein, was sich durch deren geringere Neigung
zur Abspaltung eines Kohlenmonoxidliganden erklären läût.
Bei der Reaktion von 1-Hexin mit dem Carbenkomplex 21, der
zwei elektronisch verschiedene Arylsubstituenten aufweist, trat
eine mäûig bevorzugte Anellierung des elektronenärmeren
Arylrings ein (22:23 ˆ 1.6:1).
nated to the Cr(CO) fragment could not be detected. Further
3
increase in temperature to 323 K resulted in sharp signals
once again. This behaviour can be explained by the presence
[22]
of the thermodynamically more stable S M /R P
h
diaster-
p
h
p
eomer at 253 K as a single stereoisomer. At 323 K the
interconversion of the helical conformers is fast with respect
to the NMR time scale. In the temperature range between 253
and 323 K the interconversion is slow, but the observation of
both diastereomers together could not be achieved. The
NMR spectra of the annulation product 8 revealed a single set
of signals and no temperature dependence of the NMR
spectra was observed; this is in accordance with a less
pronounced flexibility of the unsaturated seven-membered
ring of 8.
p
h
p
h
1
844
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Chem. Eur. J. 1998, 4, No. 9

Tetracyclic Arenes
1843±1851
X-ray crystal structure of tricarbonyl chromium complex 8:
The relative configuration of the benzannulation reaction
product 8 in the solid state was unequivocally established by
X-ray crystal structure analysis after suitable crystals had
been obtained from a saturated solution in n-hexane at
�
288C (Figure 3, Table 2). As expected, the tricarbonyl
chromium moiety in 8 is coordinated to the sterically less
Scheme 2. Reactions of the carbene complexes 1, 3 and 4 with
bis(trimethylsilyl)ethyne. Reagents and conditions: a) tms�CꢀC�tms
(
4 equiv), tBuOMe, 208C (408C in case of 3), 2 h; b) MeOH, 208C, 1 h.
a) 323 K
Figure 3. Molecular structure of chromium complex 8.[23]
Table 2. Selected bond lengths and dihedral angles of 8 (for atom
numbering see Figure 3, standard deviations are given in parentheses).
bond lengths [pm]
Cr1�C1
219.7(6)
226.1(7)
230.9(8)
233.9(7)
225.8(7)
224.7(7)
Cr1�C2
Cr1�C3
Cr1�C3a
Cr1�C12c
Cr1�C12b
dihedral angles [8]
C1-C12b-C12c-C3a
C3-C3a-C12c-C12b
C2-C3-C3a-C12c
C3a-C3-C2-C1
� 6.5 (0.9)
9.2 (1.0)
� 6.5 (1.0)
1.1 (1.0)
C3-C2-C1-C12b
1.4 (1.0)
C2-C1-C12b-C12c
C12-C12a-C12b-C1
C7-C6a-C12c-C12b
1.5 (1.0)
Figure 2. Temperature dependence of the CO (left) and one of the
32.2 (0.9)
� 17.9 (1.1)
CH
CDCl
2
�CH
2
bridge carbon atoms (right) of chromium complex 9 (125.6 MHz,
3
).
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K. H. Dötz et al.
FULL PAPER
crowded face of the carbon skeleton to form the
S M /R P diastereomer as a single stereoisomer
p
h
p
h
(Figure 3). As already known from related com-
pounds, the tricarbonyl chromium moiety is bound to
the arene ring in a staggered conformation in the
[
24]
solid state. In addition, the tricarbonyl chromium
fragment is coordinated in a noncentrosymmetric
manner and shifted away from the seven-membered
ring as indicated by the unequal h-C �Cr bond
arene
[
25]
lengths (Table 2). The diastereoselectivity of the
benzannulation reaction of 4, which does not contain
any stereochemical information, can be explained by
the reaction mechanism and the structure of the
central seven-membered ring of carbene complex 4.
[
16±18]
According to theoretical studies,
the formation
of the vinyl carbene complexes Aanti or Asyn repre-
sents the side-differentiating step of the reaction
mechanism (Figure 4). The rigid nonplanar structure
of the 5-(5H)-dibenzo[a.d]cycloheptenylidene moi-
[
26]
ety offers an explanation for the preferred forma-
tion of the vinyl carbene complexes Aanti that leads to
the benzannulation product 8 with the S M /R P
h
p
h
p
stereochemistry.
p h p h
Figure 4. Diastereoselective formation of S M /R P -8.
Reactions with bis(trimethylsilyl)ethyne and 4-pen-
tyn-1-ol: Two strategies have been applied in order to
explain the lack of reactivity of the carbene complexes 1 and 2
towards 1-hexyne. Reaction of the carbene complexes 1, 3 and
position of carbene complex 1 (Scheme 3). Reaction of the
xanthenylidene complex 3 afforded the tetracyclic arene 19
after silylation of the benzannulation product, whereas
reaction of 4 gave the chromium tricarbonyl complex 20
along with a 33% yield of 2-oxacyclohexylidene complex 18.
As in the reaction of carbene complex 4 with 1-hexyne, the
benzannulation product 20 is presumed to adopt the S M /
4
with bis(trimethylsilyl)ethyne led only in case of 4 to the
[
15]
expected vinyl ketene 15, which could not be isolated in
pure form (Scheme 2); addition of methanol gave a 26% yield
of methyl ester 16 after purification by preparative HPLC. As
with 1-hexyne, only the carbene dimer 14 (82% yield) could
be isolated from the reaction of carbene complex 1 with
bis(trimethylsilyl)ethyne along with a small amount of (9H)-
fluorene-9-one. Surprisingly, reaction of carbene complex 3
gave no vinyl ketene; instead, cyclopropene 17 was obtained
in a 44% yield after sublimation, representing the first
example of a cyclopropenation of an alkyne by a chromium
p
h
R P configuration.
p
h
Because no reaction giving evidence for decarbonylation
occurred between the carbene complexes 1 and 2 and the
[
27]
carbene complex.
The different reactivity of carbene
complexes 3 and 4 may be rationalized in terms of the
[
28]
conformative flexibility of the xanthene moiety. As a result,
in the presumed vinyl carbene intermediate the a-trimethyl-
silyl substituent and the xanthene carbon skeleton are occa-
sionally in the same plane. This coplanar conformation
imposes a steric strain that may be reduced by an intra-
molecular rearrangement accompanied by loss of the tetra-
carbonyl chromium fragment. As a result, the formation of
cyclopropene 17 is assumed to be faster than the Ccarbene�CˆO
coupling leading to a vinyl ketene.
Reaction of 4-pentyn-1-ol with the carbene complexes 1, 3
and 4 was expected to yield either the benzannulation
reaction products or d-lactones by intramolecular addition
of the hydroxy group to the vinyl ketene intermediate. In case
of 1, carbene dimer 14 and (9H)-fluorene-9-one were isolated
once again along with a 59% yield of pentacarbonyl(2-
oxacyclohexylidene)chromium(0) (18), resulting from alkynol
Scheme 3. Reactions of the carbene complexes 1, 3 and 4 with 4-pentyn-1-
ol. Reagents and conditions: a) 4-pentyn-1-ol (4 equiv), tBuOMe, 208C
[
29]
cyclization of 4-pentyn-1-ol with the pentacarbonyl chro-
mium fragment, which evolves during the thermal decom-
(408C in case of 3), 2 h; b) TBDMSCl (4 equiv), NEt
3
(4 equiv), 208C, 2 h.
1
846
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Tetracyclic Arenes
1843±1851
alkynes employed, we presume that the diverse reaction
In summary, the benzannulation reaction of the tricyclic
carbene complexes 3 ± 5 provides an efficient synthetic
strategy to obtain tetracyclic arenes with a defined substitu-
tion pattern on the newly formed arene ring.
behaviour of the carbene complexes 1 ± 5 reflects their
[
30]
different propensity for decarbonylation. Assuming a slow
rate of carbon monoxide dissociation from the carbene
complex 1, which benefits from a more efficient stabilization
(
compared with 4) of the metal carbene moiety as a result of
[
19]
the almost planar carbene ligand, thermal decomposition to
yield the carbene dimer 14 is much faster than decarbon-
ylation. In contrast, the nonplanarity of the dibenzo[a.d]cy-
cloheptenylidene ligand of 4 results in an enhanced propensity
for decarbonylation, which enables the alkyne coordination
that is crucial for the benzannulation reaction. In all reactions
of xanthenylidene complex 3, representing the most stable of
the carbene complexes employed, warming to 408C was
required to achieve decarbonylation; this is in accordance
with the electron-donating character of the xanthenylidene
ligand.
Experimental Section
General: All operations were carried out in flame-dried glassware under an
1
13
atmosphere of argon with standard Schlenk techniques. H and C NMR
spectra were recorded on Bruker AM250, AM400 and DRX500 spec-
trometers. All chemical shifts are given relative to TMS as external
standard. FT-IR spectra were recorded on a Nicolet Magna 550 spectrom-
eter. MS(EI) and HR-MS(EI) were determined on a Kratos MS-50
spectrometer. Elemental analyses were carried out with an Elementar-
analysator CHN-O-Rapid (Heraeus). Melting points were recorded with a
Büchi SMP20 and are uncorrected. Thin-layer chromatography (TLC):
Merck precoated sheets, 60F254; column chromatography was performed
with Merck silica gel, grade 60 (0.062 ± 0.200 mm).
Starting compounds: Dichloromethane, tert-butyl methyl ether, n-hexane
and petroleum ether (40/60) were dried by distillation from calcium
hydride under argon. Liquid starting compounds were degassed by the
freeze, pump and thaw technique and stored over molecular sieves (4 Š).
The carbene complexes 1 ± 6 and 21 were prepared according to published
Reaction of pentacarbonyl[(4-methoxyphenyl)(phenyl)car-
bene]chromium(0) (21) with 1-hexyne: Studies directed
towards the regioselectivity of the formal [3‡2‡1] cyclo-
addition reaction of diarylcarbene complexes containing two
electronically different arene substituents remain controver-
[
19]
procedures. All other chemicals were used as received from commercial
sources.
Crystal structure determination of tricarbonyl chromium complex 8:
[
4a, 31±32]
sial so far.
In order to address this aspect of the
Å
C
31
H
34CrO
4
Si ´ 0.25hexane, M ˆ 572.2, triclinic, space group P1 (no. 2),
3
benzannulation reaction, carbene complex 21 was treated
with 1-hexyne. After silylation, the two regioisomeric tricar-
bonyl complexes (22 and 23) were obtained (Scheme 4). The
red crystals, dimensions 0.05  0.13  0.40 mm , a ˆ 11.787(1), b ˆ
1
3
2
2.912(1), c ˆ 21.191(1) Š, a ˆ 85.06(1)8, b ˆ 79.17(1)8, g ˆ 75.73(1)8, Vˆ
3 � 1
� 3
067.3(4) mm ,
D
c
ˆ 1.24 Mgm
,
Z ˆ 4,
m
(CuKa) ˆ 3.708 mm
,
Tˆ
00(2) K, F(000) ˆ 1210; 8286 reflections were collected on an Enraf-
Nonius CAD4 diffractometer (2qmax ˆ 1108, � 12 ꢁ h ꢁ 0, � 13 ꢁ k ꢁ 13,
�
22 ꢁ l ꢁ 22), 7708 symmetry independent reflections (Rint ˆ 0.043) were
[
33]
used for the structure solution (direct methods) and refinement (full-
2
[34]
matrix least squares on F , 691 parameters, 58 restraints), non-hydrogen
atoms were refined anisotropically, H atoms localized by difference
electron density and refined with a riding model; wR
for I > 2s(I)]. An empirical absorption correction was applied.
2
ˆ 0.214 [R ˆ 0.076
1
[35]
The
solvent n-hexane was disordered. Crystallographic data (excluding struc-
ture factors) for the structure reported in this paper have been deposited
with the Cambridge Crystallographic Data Centre as supplementary
publication no. CCDC-101048. Copies of the data can be obtained free of
charge on application to CCDC, 12 Union Road, Cambridge CB21EZ, UK
(
fax: (‡44)1223-336-033; e-mail: deposit@ccdc.cam.ac.uk).
General procedure for the reactions of carbene complexes 1 ± 6 and 21 with
alkynes: The carbene complex (1 mmol) was dissolved in tert-butyl methyl
ether (10 mL) at � 208C. After addition of the corresponding alkyne
(
4 mmol) and three cycles of the freeze, pump and thaw technique, the
reaction mixture was stirred at room temperature until consumption of the
carbene complex was complete (1 ± 2 h, TLC control; the reactions of
carbene complex 3 required gentle warming to 408C). This was accom-
panied by a colour change from violet (1), red (2, 4 ± 6, 21) or blue (3) to
orange or colourless. After transferring the reaction mixture by syringe into
Scheme 4. Reaction of carbene complex 21 with 1-hexyne. Reagents and
conditions: a) 1-hexyne (4 equiv), tBuOMe, 208C, 2 h; b) TBDMSCl
(
4 equiv), NEt
3
(4 equiv), 208C, 2 h.
a Schlenk tube containing TBDMSCl (4 mmol, 0.6 g) and NEt (4 mmol,
3
0
.4 g), the mixture was stirred for another two hours. After removal of the
solvent under reduced pressure the residue was separated by column
chromatography under argon at � 208C.
regioselectivity (isomer ratio 22:23 ˆ 1.6:1), which was found
Reaction of pentacarbonyl[9-(9H)-fluorenylidene]chromium(0) (1) with 1-
hexyne: The reaction of 1 (1 mmol, 0.35 g) with 1-hexyne (4 mmol, 0.33 g)
afforded 9,9'-[bis-(9H)-fluorenylidene] (14) (0.13 g, 0.39 mmol, 78% with
regard to 1) after column chromatographic workup (eluent: petroleum
ether/dichloromethane ˆ 3:1).
to be in accordance with a preference for the less electron-rich
[
31]
arene already reported earlier by this group, was very low.
The regioisomers 22 and 23 have been assigned on the basis of
1
their H NMR spectra. The spectrum of the major isomer 22 is
characterized by an ABCD spin system of the resonances
assigned to the protons H5 to H8. In contrast, substitution of
proton H6 by a methoxy group results in an ABC spin system
9,9'-[Bis-(9H)-fluorenylidene] (14): Red crystals, m.p. 1868C (lit.: 185 ±
[
36]
1
1
(
878C ); R
f
ˆ 0.8 (petroleum ether/dichloromethane ˆ 3:1); H NMR
3
3
400 MHz, CDCl
.43 Hz, 4H; ArH), 7.70 (d,
3
): d ˆ 7.32 (t,
J
HH ˆ 7.82 Hz, 4H; ArH), 7.40 (t,
J
HH
ˆ
3
7
J
HH ˆ 7.43, 4H; H4, H4', H5, H5'), 8.32 (d,
in 23 that is characterized by the coupling constant between
3
13
J
HH ˆ 7.82 Hz, 4H; H1, H1', H8, H8'); C NMR (100.6 MHz, CDCl
3
): d ˆ
4
H5 and H7 ( J ˆ 1.96 Hz).
119.63 (4C; ArC
t
), 119.82 (2C; C9, C9'), 125.79 (4C; ArC
t
), 127.55 (4C;
HH
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K. H. Dötz et al.
FULL PAPER
3JHH ˆ 6.95 Hz, 1H; H9), 7.31 (dd, JHH ˆ 6.76, 8.74 Hz, 1H; H5), 7.33 ± 7.37
3
t t q q
ArC ), 129.16 (4C; ArC ), 136.51 (4C; ArC ), 140.18 (4C; ArC ); IR (KBr):
3
3
�
1
(m, 2H; H10, H11), 7.39 (d,
J
ˆ 7.15 Hz, 1H; H12), 7.65 (d,
J
HH
ˆ
nÄ ˆ 3055 (m), 1477 (m), 1444 (s, CˆC), 1348 (m), 763 (s), 721 cm (vs); MS
HH
[
37] 13
‡
8.74 Hz, 1H; H4);
C NMR (125.6 MHz, CDCl , 253 K): d ˆ � 3.53
(
70 eV, EI): m/z (%): 328 (100) [M ], 300 (10), 163 (15); HR-MS (EI): calcd
3
‡
(SiCH ), � 2.04 (SiCH ), 14.23 (C4'), 18.73 (C(CH ) ), 22.99 (C3'), 25.59
for C26
H
16: 328.1252; found 328.1247 (100%, [M ]).
3
3
3 3
(
3C; C(CH
3
)
3
), 29.97 (C2'), 33.18 (C1'), 93.93 (C1), 103.08 (Ar-h-C
q
),
Reaction of exo-pentacarbonyl{spiro-(1''H)-indeno-(1'',1')-cycloprop[2',3'-
b]-1-(1H)-indanylidene}chromium(0) (2) with 1-hexyne: The reaction of 2
1
05.06 (Ar-h-C
q
), 106.11 (Ar-h-C ), 106.61 (Ar-h-C ), 122.63 (C4), 127.74
q
q
(
C5), 129.42 (C11), 129.76 (C10), 130.24 (C6), 130.69 (C3), 131.16 (C9),
31.89 (C12), 132.66 (C8), 133.75 (C7), 135.83 (ArC ), 137.13 (ArC ), 137.29
), 233.68 (3C; CO); FT-IR (hexane): nÄ ˆ 1957 (vs, CˆO, A
(
1 mmol, 0.42 g) with 1-hexyne (4 mmol, 0.33 g) followed by column
1
q
q
chromatographic workup (eluent: petroleum ether/dichloromethane ˆ 1:1)
afforded 0.36 g of an orange mixture of compounds that could not be
separated.
[
38]
(
(
4
ArC
q
1
), 1894
�
1
‡
s, CˆO, E), 1880 cm (s, CˆO, E); MS (70 eV, EI): m/z (%): 550 (8) [M ],
‡
‡
‡
94 (4) [M � 2CO], 466 (100) [M � 3CO], 414 (40) [M � Cr(CO)
3
], 357
Reaction of pentacarbonyl[9-(9H)-xanthenylidene]chromium(0) (3) with
(14) [M
73 (9) [Si(CH )
‡
� Cr(CO) � C H ], 300 (16) [M
‡
� Cr(CO) � 2C H ], 126 (31),
3
4
9
3
4
9
1-hexyne: The reaction of 3 (1 mmol, 0.37 g) with 1-hexyne (4 mmol,
‡
‡
31 34 4
], 52 (3) [Cr ]; HR-MS (EI): calcd for C H CrO Si:
3
3
0.33 g) at 408C afforded an orange solution. Column chromatographic
‡
31 34 4
550.1631; found 550.1629 (8%, [M ]); C H CrO Si (550.69): calcd C 67.61,
workup (eluent: petroleum ether/dichloromethane ˆ 2:1) gave the ben-
zannulation product 11 (0.17 g, 0.42 mmol, 42%) and the corresponding
tricarbonyl chromium complex 7 (0.14 g, 0.26 mmol, 26%).
H 6.22; found C 67.93, H 6.34.
Reaction of pentacarbonyl{5-(5H)-dibenzo[a.d]cycloheptylidene}chromi-
um(0) (5) with 1-hexyne: The reaction of 5 (1 mmol, 0.38 g) with 1-hexyne
(4 mmol, 0.33 g) afforded an orange reaction mixture. Silylation and
column chromatographic workup (eluent: petroleum ether/dichloro-
methane ˆ 2:1) gave impure 2-butyl-3-tert-butyldimethylsilyloxy-7,8-dihy-
dro-benzo[4,5]cyclohepta[1,2,3-de]naphthalene (12) (<5%, identified by
mass spectrometry), tricarbonyl chromium complex 9 (0.15 g, 0.27 mmol,
27%) and the thermolabile unprotected tetracyclic benzannulation prod-
2
-Butyl-3-tert-butyldimethylsilyloxy-benzo[k.l]xanthene (11): Colourless
1
crystals;
R
f
ˆ 0.9 (petroleum ether/dichloromethane ˆ 2:1);
H NMR
3
(
500 MHz, CDCl
3
): d ˆ 0.20 (s, 6H; Si(CH
3
)
2
), 0.95 (t, JHH ˆ 7.34 Hz, 3H;
HH ˆ 7.34 Hz, 2H; H3'), 1.64
3
H4'), 1.11 (s, 9H; C(CH
3
)
3
), 1.42 (psex,
J
3
3
(
J
pquin, JHH ˆ 7.34 Hz, 2H; H2'), 2.76 (t, JHH ˆ 7.34 Hz, 2H; H1'), 6.85 (d,
3
3
3
HH ˆ 7.45 Hz, 1H; ArH), 7.05 (d, JHH ˆ 8.34 Hz, 1H; ArH), 7.07 (t, JHH
ˆ
ˆ
3
3
[39]
7.95 Hz, 1H; ArH), 7.21 (t,
J
HH ˆ 7.25 Hz, 1H; ArH), 7.32 (t,
J
HH
uct 13 (0.08 g, 0.26 mmol, 26%).
3
7
.95 Hz, 1H; ArH), 7.45 (s, 1H; H1), 7.47 (d,
J
HH ˆ 8.75 Hz, 1H; ArH),
2
-Butyl-3-tert-butyldimethylsilyloxy-7,8-dihydro-benzo[4,5]cyclohep-
13
7
.77 (d, 3
3.12 (2C; Si(CH
3C; C(CH ), 30.55 (C2'), 32.60 (C1'), 107.32 (ArC
), 116.93 (ArC ), 120.32 (ArC ), 121.00 (ArC
), 123.24 (ArC ), 126.23 (ArC ), 128.77 (ArC
J
HH ˆ 7.55 Hz, 1H; ArH); C NMR (125.6 MHz, CDCl
), 14.08 (C4'), 16.69 (C(CH ), 22.69 (C3'), 26.08
3
): d ˆ
ta[1,2,3-de]-naphthalene (12): Colourless oil; R
f
ˆ 0.7; MS (70 eV, EI): m/z
�
3
)
2
3
)
3
‡
‡
‡
(
2
(
%): 416 (3) [M ], 359 (3) [M � C
4
H
9
], 302 (100) [M � 2C
4 9
H ], 274 (15),
(
3
)
3
t
), 115.37 (ArC
t
),
),
),
‡
‡
59 (30) [M � 2C
4
H
9
� CH
3
� Si], 245 (19) [M � C
4
H
9
� TBDMS], 231
1
1
1
16.89 (ArC
22.13 (ArC
29.49 (ArC
t
t
q
q
), 121.55 (ArC
), 129.47 (ArC
q
45); HR-MS (EI): calcd for C28
H
36OSi: 416.2535; found 416.2544 (3%,
t
t
t
t
q
‡
[
M ]).
q
), 146.86 (C3), 151.06, 151.54 (2C; C6a, C6b); MS (70 eV, EI):
‡
‡
‡
Tricarbonyl{1-3a:12c-12b-h-[2-butyl-3-tert-butyldimethylsilyloxy-7,8-dihy-
drobenzo[4,5]cyclohepta[1,2,3-de]naphthalene]}chromium(0) (9): Red
m/z (%): 404 (100) [M ], 347 (15) [M � C
4
H
9
], 290 (60) [M � 2C
4 9
H ], 73
Si: 404.2171; found
‡
(
30) [Si(CH
3
)
3
]; HR-MS (EI): calcd for C26
H
32
O
2
‡
crystals; m.p. 768C (decomp);
R
f
ˆ 0.4 (petroleum ether/dichloro-
4
7
04.2167 (100%, [M ]); C26
7.08, H 8.04.
32 2
H O Si (404.62): calcd C 77.18, H 7.91; found C
1
methane ˆ 2:1); H NMR (500 MHz, CDCl
3
, 298 K): d ˆ 0.49 (s, 3H;
3
SiCH
C(CH
3
), 0.53 (s, 3H; SiCH
3
), 0.95 (t, JHH ˆ 7.25 Hz, 3H; H4'), 1.13 (s, 9H;
Tricarbonyl[1-3a:11c-11b-h-(2-butyl-3-tert-butyldimethylsilyloxy-ben-
zo[k.l]xanthene)]chromium(0) (7): Orange crystals; m.p. 858C (decomp);
), 1.28 (psex, 3
3
2,3
)
J
3
J
HH ˆ 7.35 Hz, 2H; H3'), 1.62 (m, 2H; H2'), 2.68
2,3
(
ddd,
HH ˆ 5.12, 11.72, 14.00 Hz, 1H; H1'), 2.84 (ddd,
J
HH ˆ 5.12, 11.52,
1
R
CDCl
f
ˆ 0.45 (petroleum ether/dichloromethane ˆ 2:1); H NMR (500 MHz,
1
4.11 Hz, 1H; H1'), 3.01 (br, 2H; H7 or H8), 3.27 (br, 2H; H7 or H8), 5.88
3
3
, 253 K): d ˆ 0.49 (s, 3H; SiCH
3
), 0.52 (s, 3H; SiCH
3
), 1.02 (t, JHH
ˆ
3
3
(
s, 1H; H1), 6.86 (d, JHH ˆ 6.26 Hz, 1H; ArH), 6.99 (d, JHH ˆ 7.35 Hz, 1H;
3 3
3
7.66 Hz, 3H; H4'), 1.15 (s, 9H; C(CH
3
)
3
), 1.5 (psex,
J
HH ˆ 7.66 Hz, 2H;
ArH), 7.03 (dd, JHH ˆ 6.75, 8.84 Hz, 1H; ArH), 7.17 (t, JHH ˆ 6.85 Hz, 1H;
3
2
H3'), 1.69 (pquin,
J
HH ˆ 7.66 Hz, 2H; H2'), 2.48 (dt,
J
HH ˆ 13.55 Hz,
3
3
ArH), 7.23 (t, JHH ˆ 7.63 Hz, 1H; ArH), 7.81 (d, JHH ˆ 7.83 Hz, 1H; ArH),
3
2
3
J
HH ˆ 7.66 Hz, 1H; H1'), 2.85 (dt,
J
HH ˆ 13.55 Hz,
J
HH ˆ 7.66 Hz, 1H;
3
13
8
.18 (d, JHH ˆ 8.74 Hz, 1H; ArH); C NMR (125.6 MHz, CDCl
), � 2.23 (SiCH ), 13.99 (C4'), 18.94 (C(CH
C3'), 25.94 (3C; C(CH ), 29.77 (C2'), 32.72 (C1'), 34.66 (br; C8), 40.03
C7), 100.97 (Ar-h-C ), 103.05 (Ar-h-C
), 127.18 (ArC ), 127.93 (ArC
), 141.19 (ArC ), 143.49 (ArC
, 253 K): d ˆ � 3.45 (SiCH
), 22.97 (C3'), 25.71 (3C; C(CH
C1'), 34.56 (C8), 39.83 (C7), 100.97 (Ar-h-C ), 101.32 (Ar-h-C
C1), 103.28 (Ar-h-C ), 106.48 (Ar-h-C ), 124.97 (ArC ), 125.76 (ArC
), 127.01 (ArC ), 127.84 (ArC ), 128.72 (ArC ), 130.62 (C3),
), 137.21 (ArC ), 141.16 (ArC ), 143.28 (ArC ), 233.28 (3C;
),
3
, 298 K):
3
3
H1'), 5.81 (s, 1H; H1), 6.81 (d,
7
1
NMR (125.6 MHz, CDCl
1
3
J
HH ˆ 6.08 Hz, 1H; H6), 7.09 (t,
J
HH
ˆ
d ˆ � 3.06 (SiCH
3
3
3 3
) ), 23.00
3
3
.65 Hz, 1H; H10), 7.07 (d, JHH ˆ 7.65 Hz, 1H; H8), 7.36 (t, JHH ˆ 7.65 Hz,
(
(
1
1
3 3
)
3
[37] 13
H; H9), 7.45 (m, 2H; H4, H5), 7.69 (d, JHH ˆ 7.64 Hz, 1H; H11);
, 253 K): d ˆ � 3.73 (q; SiCH ), � 1.89 (q; SiCH
4.14 (q; C4'), 18.76 (s; C(CH ), 22.89 (t; C3'), 25.92 (q, 3C; C(CH
0.28 (t; C2'), 33.06 (t; C1'), 82.30 (d; C1), 92.06 (s; Ar-h-C
), 104.11 (s; Ar-h-C ), 104.55 (s; Ar-h-C ), 108.22 (d; ArC
ArC ), 117.15 (d; ArC ), 117.68 (s; C10a), 122.46 (d; ArC ), 124.04 (d; ArC
27.53 (s; C3), 130.04 (d; ArC ), 130.78 (d; ArC ), 150.64, 151.52 (s, 2C; C6a,
C6b), 233.39 (s; 3C, CO); FT-IR (hexane): nÄ ˆ 1963 (vs, CˆO, A
C
q
q
), 125.3 (ArC
), 128.68 (ArC
), 233.23 (3C; CO); 13C NMR
t
), 125.45 (ArC
), 132.24 (ArC
t
),
),
3
3
3
),
),
26.86 (ArC
37.44 (ArC
t
t
t
t
t
3
)
3
3 3
)
q
q
q
q
), 92.56 (s; Ar-h-
), 116.08 (d;
),
(
(
(
(
125.6 MHz, CDCl
C4'), 18.82 (C(CH
3
3
), � 2.24 (SiCH
), 29.54 (C2'), 32.98
), 102.51
),
3
), 14.15
C
q
q
q
t
3
)
3
3 3
)
t
t
t
t
q
q
1
t
t
q
q
t
t
1
), 1901 (s,
1
1
26.79 (ArC
t
t
t
t
�
1
‡
CˆO, E), 1889 cm (sh, CˆO, E); MS (70 eV, EI): m/z (%): 540 (18) [M ],
32.29 (ArC
t
q
q
q
‡
‡
‡
4
84 (5) [M � 2CO], 456 (100) [M � 3CO], 404 (95) [M � Cr(CO)
3
], 290
], 52 (14) [Cr ];
[40]
CO); FT-IR (KBr): nÄ ˆ 2958 (m), 2927 (m), 2858 (m), 1952 (vs, CˆO, A
1
‡
‡
‡
(
40) [M � Cr(CO)
3
� 2C
4
H
9
], 126 (40), 73 (30) [Si(CH
3
)
3
1
1
880 (vs, CˆO, E), 1849 (vs, CˆO, E), 1460 (m, CˆC), 1363 (m), 1261 (m),
HR-MS (EI): calcd for C29
H
32CrO
5
Si: 540.1424; found 540.1404 (18%,
� 1
103 (m, Si-O-C), 864 (m), 804 cm (m); MS (70 eV, EI): m/z (%): 552 (0.3)
‡
[
M ]).
‡
‡
‡
‡
[
M ], 496 (0.2) [M � 2CO], 468 (33) [M � 3CO], 416 (100) [M �
‡
‡
Reaction of pentacarbonyl{5-(5H)-dibenzo[a.d]cycloheptenylidene}chro-
mium(0) (4) with 1-hexyne: The reaction of 4 (1 mmol, 0.38 g) with 1-
hexyne (4 mmol, 0.33 g) afforded an orange solution. After silylation and
Cr(CO) ], 359 (32) [M � Cr(CO) � C H ], 302 (40) [M � Cr(CO) �
‡ ‡
3
3
4
9
3
2C H ], 287 (20) [M � Cr(CO) � C H � CH ], 84 (20) [C H Si ], 73
4
9
3
4
9
3
4
8
‡
(22) [Si(CH ) ]; HR-MS (EI): calcd for C H CrO Si: 552.1788; found
3
3
31 36
4
‡
column
chromatographic
workup
/R
(eluent:
-8 were obtained.
petroleum
ether/
31 36 4
552.1787 (0.3%, [M ]); C H CrO Si (552.71): calcd C 67.37; H 6.57; found
dichloromethane ˆ 2:1) 0.30 g S
p
M
h
p
P
h
C 66.59, H 6.56.
S
p
M
h
p h
/R P -Tricarbonyl{1-3a:12c-12b-h-(2-butyl-3-tert-butyldimethylsilyl-
2-Butyl-7,8-dihydro-3-hydroxybenzo[4,5]cyclohepta[1,2,3-de]naphthalene
oxy-benzo[4,5]cyclohepta[1,2,3-de]naphthalene)}chromium(0) (8): Orange
(13): Colourless unstable solid;
R
f
ˆ 0.25 (petroleum ether/
1
3
crystals; m.p. 105 ± 1088C (decomp),
R
f
ˆ 0.55 (petroleum ether/
dichloromethane ˆ 2:1); H NMR (500 MHz, C
6
D
6
): d ˆ 0.92 (t,
J
HH
ˆ
1
3
dichloromethane ˆ 2:1); H NMR (500 MHz, CDCl
3
, 253 K): d ˆ 0.45 (s,
7.50 Hz, 3H; H4'), 1.31 (psex,
J
J
HH
ˆ
7.50 Hz, 2H; H3'), 1.55 (pquin,
3
3
3
6
(
H; Si(CH
3
)
2
), 1.01 (t, JHH ˆ 7.55 Hz, 3H; H4'), 1.12 (s, 9H; C(CH
3
)
3
2
), 1.51
HH ˆ 7.50 Hz, 2H; H2'), 2.52 (t, JHH ˆ 7.50 Hz, 2H; H1'), 3.06 (br, 2H; H7
3
3
m, 2H; H3'), 1.72 (pquin,
J
HH ˆ 7.55 Hz, 2H; H2'), 2.52 (dt,
J
J
HH
ˆ
or H8), 3.28 (br, 2H; H7 or H8), 4.86 (s, 1H; OH), 7.14 (d, JHH ˆ 7.25 Hz,
3
2
3
3
15.51 Hz,
J
HH ˆ 7.55 Hz, 1H; H1'), 2.82 (dt,
J
HH ˆ 15.51 Hz,
HH
ˆ
1H; ArH), 7.18 (d, JHH ˆ 6.85 Hz, 1H; ArH), 7.27 ± 7.29 (m, 1H; ArH), 7.34
.55 Hz, 1H; H1'), 5.67 (s, 1H; H1), 6.46 (d, 3JHH ˆ 12.32 Hz, 1H; H7),
(t, JHH ˆ 8.09 Hz, 1H; ArH), 7.35 (t, JHH ˆ 7.91 Hz, 1H; ArH), 7.54 (s, 1H;
3
3
7
6
3
3
3
3
.58 (d, JHH ˆ 12.32 Hz, 1H; H8), 7.05 (d, JHH ˆ 6.76 Hz, 1H; H6), 7.15 (d,
H1), 7.69 (d, JHH ˆ 7.65 Hz, 1H; ArH), 8.39 (d, JHH ˆ 8.35 Hz, 1H; ArH);
1
848
ꢀ WILEY-VCH Verlag GmbH, D-69451 Weinheim, 1998 0947-6539/98/0409-1848 $ 17.50+.50/0 Chem. Eur. J. 1998, 4, No. 9

Tetracyclic Arenes
1843±1851
13C NMR (125.6 MHz, C
D
): d ˆ 14.12 (C4'), 22.79 (C3'), 29.69 (C2'), 32.36
6
6
Separation by preparative HPLC (n-hexane/diethyl etherˆ 95:5) gave
methyl ester 16 (0.11 g, 0.26 mmol, 22%).
(
C1'), 35.33 (C8), 40.33 (C7), 120.64 (ArC
t
), 121.39 (ArC
), 127.04 (ArC ), 127.11 (ArC
), 132.19 (ArC ), 133.31 (ArC
), 143.77 (ArC
q
), 124.49 (ArC
), 127.75 (ArC
), 140.43 (ArC
t
),
),
),
1
1
1
26.54 (ArC
31.12 (ArC
41.86 (ArC
q
), 126.72 (ArC
), 131.42 (ArC
t
t
t
t
{
[5'-(5'H)-Dibenzo[a.d]cycloheptenylidene]trimethylsilyl}methyltrimethyl-
silylketene (15): R
ˆ 0.4 (dichloromethane); FT-IR (KBr): nÄ ˆ 2954 (m),
923 (m), 2853 (m), 2077 (vs, CˆCˆO), 1257 (s), 842.9 (vs), 802 cm (s);
q
q
t
t
q
f
q
q
), 149.31 (C3); FT-IR (KBr): nÄ ˆ 3566 (m,
�
1
2
O�H), 3022 (m), 2953 (m), 2926 (m), 2853 (m), 1598 (w), 1504 (w), 1377
‡
‡
MS (70 eV, EI): m/z (%): 388 (18) [M ], 360 (40) [M � CO], 287 (35)
�
1
(
w), 1171 (m), 770 (s), 752 cm (m); MS (70 eV, EI): m/z (%): 302 (100)
‡
‡
[
7
M � CO � Si(CH
3
)
3
], 272 (100) [M � CO � Si(CH
3
)
3
� CH
3
], 218 (27),
‡
‡
‡
‡
[
(
M ], 287 (5) [M � CH
3
], 259 (38) [M � C
3
H
7
], 245 (18) [M � C
4 9
H ], 231
‡
3 (88) [Si(CH
88.1680 (18%, [M ]).
3
)
3
]; HR-MS (EI): calcd for C24
H
28OSi
2
: 388.1679; found
‡
14) [M � C
4
H
9
� CH
2
], 215 (20), 202 (8); HR-MS (EI): calcd for C22
H
22O:
‡
3
‡
3
02.1671, found 302.1672 (100%, [M ]).
Methyl-2,3-bis(trimethylsilyl)-3-{5'-(5'H)-dibenzo[a.d]cycloheptenylidene}-
Reaction of pentacarbonyl[bis(4-methoxyphenyl)carbene]chromium(0)
propionate (16): Colourless solid; m.p. 1018C; R
f
ˆ 0.55 (petroleum ether/
): d ˆ � 0.22 (s, 9H;
), 3.67 (s, 3H; OCH ), 4.04 (s, 1H; H2),
.93 (d, JHH ˆ 11.68 Hz, 1H; Halkene), 6.98 (d, JHH ˆ 11.68 Hz, 1H; Halkene),
(
(
6) with 1-hexyne: The reaction of 6 (1 mmol, 0.42 g) with 1-hexyne
4 mmol, 0.33 g) gave tricarbonyl chromium complex 10 (0.36 g, 0.62 mmol,
1
diethyl etherˆ 2:1); H NMR (500 MHz, CDCl
3
Si(CH
6
3
)
3
3
), � 0.17 (s, 9H; Si(CH
3
)
3
3
62%) after silylation and column chromatographic workup (eluent:
3
petroleum ether/dichloromethane ˆ 1:1).
Tricarbonyl{1-4a:8a-h-[3-butyl-4-tert-butyldimethylsilyloxy-6-methoxy-1-
3
3
7.19 (d, JHH ˆ 7.63 Hz, 1H; ArH), 7.23 (t, JHH ˆ 7.55 Hz, 1H; ArH), 7.26 ±
7.28 (m, 2H; ArH), 7.32 ± 7.39 (m, 4H; ArH); 13C NMR (62.5 MHz, CDCl ):
3
(
(
4'-methoxy)phenyl-naphthalene]}chromium(0) (10): Red crystals; R
f
ˆ 0.6
d ˆ � 0.15 (3C; Si(CH ) ), 2.19 (3C; Si(CH ) ), 42.77 (C2), 50.92 (OCH ),
3
3
3
3
3
1
petroleum ether/dichloromethane ˆ 1:1); H NMR (500 MHz, CDCl
3
):
t t t t t
126.33 (ArC ), 126.89 (ArC ), 127.16 (ArC ), 127.60 (ArC ), 128.03 (ArC ),
3
d ˆ 0.52 (s, 3H; SiCH
3
), 0.58 (s, 3H; SiCH
3
), 0.97 (t, JHH ˆ 7.52 Hz, 3H;
t t t t
128.32 (ArC ), 128.50 (2C; ArC ), 131.14 (ArC ), 131.35 (ArC ), 133.79
(ArC ), 135.01 (ArC ), 137.95 (ArC ), 139.49 (ArC ), 141.13 (ArC ), 149.41
q q q q q
3
H4''), 1.18 (s, 9H; C(CH
3
)
3
), 1.49 (psex,
J
HH ˆ 7.52 Hz, 2H; H3''), 1.68
3
2
3
(
1
pquin, JHH ˆ 7.52 Hz, 2H; H2''), 2.58 (dt, JHH ˆ 15.51 Hz, JHH ˆ 7.52 Hz,
(ArC ), 175.19 (CˆO); FT-IR (KBr): nÄ ˆ 3063 (m), 3013 (m), 2949 (m),
q
2
3
� 1
H; H1''), 2.87 (dt, JHH ˆ 15.51 Hz, JHH ˆ 7.52 Hz, 1H; H1''), 3.89 (s, 3H;
2897 (m), 1724 (s), 1703 (vs, CˆO), 1433 (m), 1246 (vs), 843 (vs), 791 cm
3
‡
‡
OCH
3
), 3.95 (s, 3H; OCH
3
), 5.48 (s, 1H; H2), 7.04 (d, JHH ˆ 8.54 Hz, 2H;
(m); MS (70 eV, EI): m/z (%): 420 (35) [M ], 405 (25) [M � CH ], 316 (28)
3
3
4
4
‡
‡
H3', H5'), 7.06 (dd, JHH ˆ 9.49 Hz, JHH ˆ 2.53 Hz, 1H; H7), 7.15 (d, JHH
ˆ
[M � OCH � Si(CH ) ], 301 (20) [M � OCH � Si(CH ) � CH ], 287
3
3
3
3
3
3
3
3
‡
‡
2
.53 Hz, 1H; H5), 7.57 (br, 2H; H2', H6'), 7.73 (d, JHH ˆ 9.49 Hz, 1H; H8);
(10) [M � OCH � Si(CH ) � CHO], 272 (26) [M � OCH � Si(CH ) �
3
3
3
3
3 3
1
3
‡
C NMR (125.6 MHz, CDCl
C4''), 18.88 (C(CH ), 22.88 (C3''), 25.84 (3C; C(CH
2.71 (C1''), 55.37 (OCH ), 55.52 (OCH ), 95.61 (C2), 99.85 (Ar-h-C
00.35 (C5), 102.05 (Ar-h-C ), 105.25 (Ar-h-C ), 107.80 (Ar-h-C ), 113.89
3
): d ˆ � 3.07 (SiCH
3
), � 1.69 (SiCH
), 29.99 (C2''),
),
3
), 13.97
CHO � CH ], 215 (80) [M � OCH � CO � 2Si(CH ) ], 147 (30), 89 (20),
3
3
3 3
(
3
1
3
)
3
3
)
3
73 (100) [Si(CH )
‡
]; HR-MS (EI): calcd for C H O Si : 420.1941; found
3
3
25 32
2
2
‡
3
3
q
25 32 2 2
420.1949 (35%, [M ]); C H O Si (420.7): calcd C 71.38, H 7.67; found C
q
q
q
71.26, H 7.71.
(
(
(
2C; C3', C5'), 122.42 (C7), 128.02 (C4), 129.72 (C8), 129.89 (C1'), 132.16
Reaction of pentacarbonyl[9-(9H)-fluorenylidene]chromium(0) (1) with 4-
pentyn-1-ol: The reaction of 1 (1 mmol, 0.35 g) with 4-pentyn-1-ol (4 mmol,
[
38]
2C; C2', C6'), 158.77, 159.76 (2C; C6, C4'), 233.94 (3C; CO); FT-IR
�
1
hexane): nÄ ˆ 1956 (vs, CˆO, A ), 1889 (s, CˆO, E), 1876 cm (s, CˆO, E);
1
0
.33g) afforded 14 (0.075 g, 0.23 mmol, 46% with regard to 1) and 2-
‡
‡
MS (70 eV, EI): m/z (%): 586 (9) [M ], 530 (2) [M � 2CO], 502 (100)
oxacyclohexylidene complex 18 (0.16 g, 0.59 mmol, 59%) after column
chromatographic workup (eluent: petroleum ether/dichloromethane ˆ
‡
‡
‡
[
3
M � 3CO], 450 (78) [M � Cr(CO)
3
], 393 (109 [M � Cr(CO)
3
� C
4
H
9
],
‡
‡
36 (26) [M � Cr(CO)
3
� 2C
4
H
9
], 126 (29), 73 (53) [Si(CH
3
)
3
], 52 (25)
3
:1).
‡
[
Cr ]; HR-MS (EI): calcd for C31
H
38CrO
6
Si: 586.1843; found 586.1843
‡
Pentacarbonyl(2-oxacyclohexylidene)chromium(0) (18): Orange crystals;
(
9%, [M ]); C31
H
38CrO
6
Si (586.72): calcd C 63.46, H 6.53; found C 63.53, H
m.p. 488C (decomp); R
H NMR (500 MHz, CDCl
f
ˆ 0.5 (petroleum ether/dichloromethane ˆ 3:1);
6
.57.
1
3
3
): d ˆ 1.65 (pquin,
J
HH ˆ 7.13 Hz, 2H; CH
2
),
Reaction of pentacarbonyl[9-(9H)-fluorenylidene]chromium(0) (1) with
bis(trimethylsilyl)ethyne: The reaction of 1 (1 mmol, 0.35 g) with bis(tri-
methylsilyl)ethyne (4 mmol, 0.68 g) afforded 9,9'-[bis-(9H)-fluorenylidene]
3
), 3.49 (t, 3
1
4
(
.87 (pquin,
J
HH ˆ 6.68 Hz, 2H; CH
2
J
HH ˆ 6.85 Hz, 2H; H6),
3
13
.62 (t, JHH ˆ 5.96 Hz, 2H; H3); C NMR (125.6 MHz, CDCl
3
): d ˆ 15.7
2 2
CH ), 21.3 (CH ), 52.8 (C6), 74.9 (C3), 216.6 (4C; COcis), 224.1 (1C;
(
14) (0.14 g, 0.41 mmol, 82% with regard to 1) and a small amount of (9H)-
COtrans), 355.7 (1C; Ccarbene); FT-IR (hexane): nÄ ˆ 2063 (m, CˆO, A
), 1986
1
fluorene-9-one (<5%) after column chromatographic workup (eluent:
petroleum ether/dichloromethane ˆ 3:1).
Reaction of pentacarbonyl[9-(9H)-xanthenylidene]chromium(0) (3) with
bis(trimethylsilyl)ethyne: The reaction of 3 (1 mmol, 0.37 g) with bis(tri-
�
1
(
w, CˆO, B), 1944 cm (vs, CˆO, E, A
1
); MS (70 eV, EI): m/z (%): 276 (25)
‡
‡
‡
‡
[
M ], 248 (12) [M � CO], 220 (8) [M � 2CO], 192 (12) [M � 3CO], 164
‡
‡
‡
(24) [M � 4CO], 136 (90) [M � 5CO], 108 (12), 80 (22), 52 (100) [Cr ];
C H CrO (276.17): calcd C 43.49, H 2.92; found C 43.44, H 3.09.
10
8
6
methylsilyl)ethyne (4 mmol, 0.68 g) afforded
mixture. Column chromatographic workup (eluent: petroleum ether/
a pale yellow reaction
Reaction of pentacarbonyl[9-(9H)-xanthenylidene]chromium(0) (3) with
-pentyn-1-ol: The reaction of 3 (1 mmol, 0.37 g) with 4-pentyn-1-ol
4
dichloromethane ˆ 2:1) followed by sublimation gave cyclopropene 17
afforded a pale yellow reaction mixture. In situ silylation and column
chromatographic workup (eluent: petroleum ether/dichloromethane ˆ 2:1)
gave the benzannulation product 19 (0.12 g, 0.24 mmol, 68%) as a yellow
(
0.15 g, 0.44 mmol, 44%).
2
,3-Bis(trimethylsilyl)-spiro{cyclopropene[1.9']-(9'H)-xanthene} (17): Pale
1
[39]
yellow crystals; m.p. 858C; R
f
ˆ 0.6; H NMR (500 MHz, CDCl
3
): d ˆ 0.17
oil, which slowly decomposed even at � 388C.
3
(
4
s, 18H; 2 Â Si(CH
3
)
3
), 6.57 (d, JHH ˆ 6.86 Hz, 2H; ArH), 6.85 ± 6.93 (m,
2
-(3-tert-Butyldimethylsilyloxy)propyl-3-tert-butyldimethylsilyloxyben-
1
3
H; ArH), 7.00 ± 7.05 (m, 2H; ArH); C NMR (125.6 MHz, CDCl
0.68 (6C; 2 Â Si(CH ), 29.79 (C1), 115.12 (2C; ArC ), 122.10 (2C; C2,
), 124.38 (2C; ArC ), 125.73 (2C; ArC ), 131.87 (2C;
3
): d ˆ
zo[k.l]xanthene (19): Yellow unstable oil; R
f
ˆ 0.5 (petroleum ether/
): d ˆ 0.06 (s, 6H;
), 0.92 (s, 9H; C(CH ), 1.11 (s, 9H;
), 1.87 (m, 2H; H2'), 2.82 (m, 2H; H1'), 3.66 (t, JHH ˆ 6.31 Hz, 2H;
�
3
)
3
t
1
dichloromethane ˆ 2:1); H NMR (500 MHz, CDCl
3
C3), 122.29 (2C; ArC
t
t
t
Si(CH
C(CH
H3'), 6.84 (d, JHH ˆ 7.65 Hz, 1H; ArH), 7.04 (d, JHH ˆ 8.12 Hz, 1H; ArH),
3
)
2
), 0.19 (s, 6H; Si(CH
3
)
2
3 3
)
C8a', C9a'), 153.25 (2C; C4a', C4b'); FT-IR (KBr): nÄ ˆ 3037 (w), 2960 (w),
3
3 3
)
�
1
1
728 (m), 1483 (s), 1446, (s), 1261 (vs), 847 (vs), 760 cm (vs); MS (70 eV,
3
3
‡
‡
‡
EI): m/z (%): 350 (45) [M ], 335 (3) [M � CH
3
], 277 (80) [M � Si(CH
3
)
3
],
3
3
7
J
.07 (t, JHH ˆ 7.75 Hz, 1H; ArH), 7.20 (t, JHH ˆ 7.75 Hz, 1H; ArH), 7.29 (t,
‡
‡
2
62 (85) [M � Si(CH
3
)
3
� CH
3
], 247 (5) [M � Si(CH
3
)
3
� 2CH
3
], 73 (100)
3
3
HH ˆ 8.05 Hz, 1H; ArH), 7.46 (s, 1H; H1), 7.47 (d,
J
HH ˆ 8.49 Hz, 1H;
ArH), 7.78 (d, JHH ˆ 7.35 Hz, 1H; ArH); C NMR (125.6 MHz, CDCl ):
d ˆ � 5.26 (2C; Si(CH ), � 3.07 (2C; Si(CH ), 18.40 (C(CH ), 18.71
C(CH ), 26.02 (3C; C(CH ), 26.12 (3C; C(CH ), 27.28 (C2'), 33.30
(C1'), 62.80 (C3'), 107.39 (ArC ), 115.34 (ArC ), 116.94 (2C; ArC ), 120.37
), 121.62 (ArC ), 122.15 (ArC ), 123.27 (ArC ), 126.26
), 128.80 (ArC ), 129.52 (ArC ), 146.99 (C3), 151.06,
‡
[
Si(CH
3
)
3
]; HR-MS (EI): calcd for C21
H
26OSi
2
: 350.1522; found 350.1519
3
13
3
‡
(
45%, [M ]); C21
H26OSi (350.61): calcd C 71.94, H 7.47; found C 71.89, H
2
3
)
2
3
)
2
3 3
)
7.79.
(
3
)
3
3
)
3
3 3
)
Reaction of pentacarbonyl{5-(5H)-dibenzo[a.d]cycloheptenylidene}chro-
mium(0) (4) with bis(trimethylsilyl)ethyne: The reaction of 4 (1 mmol,
t
t
t
(ArC
(ArC
q
), 120.96 (ArC
), 128.07 (ArC
q
q
t
t
0.38 g) with bis(trimethylsilyl)ethyne (4 mmol, 0.68 g) afforded a colourless
t
q
t
q
reaction mixture. Column chromatographic workup (eluent: petroleum
151.52 (C6a, C6b); FT-IR (film): nÄ ˆ 2954 (s), 2929 (s), 2858 (s), 1600 (m),
� 1
ether/dichloromethane ˆ 5:1) gave impure vinyl ketene 15 as colourless
1485 (s), 1402 (s), 1263 (vs, CO-Si), 1108 (s), 966 (s), 843 (vs), 768 cm (s);
‡
‡
solid. After dissolving in CH
2
Cl
2
(20 mL) and addition of methanol (1 mL)
MS (70 eV, EI): m/z (%): 520 (100) [M ], 505 (2) [M � CH
3
], 463 (5)
‡
‡
the reaction mixture was strirred at room temperature for one hour.
[M � C
4
H
9
], 348 (12) [M � C
4 9
H
� TBDMS], 147 (20), 73 (50)
Chem. Eur. J. 1998, 4, No. 9
ꢀ WILEY-VCH Verlag GmbH, D-69451 Weinheim, 1998
0947-6539/98/0409-1849 $ 17.50+.25/0
1849

K. H. Dötz et al.
FULL PAPER
‡
[
(
Si(CH
3
)
3
]; HR-MS (EI): calcd for C31
H
44
O
3
Si
2
: 520.2829; found 520.2821
1.96 Hz, 1H; H5), 7.38 ± 7.60 (m, 5H; H2', H3', H4', H5', H6'), 7.72 (d,
‡
3
13
100%, [M ]).
J
�
HH ˆ 9.44 Hz, 1H; H8); C NMR (125 MHz, CDCl
3
): d ˆ � 3.46 (SiCH
3
),
1.71 (SiCH
3
), 14.07 (C4''), 18.76 (C(CH
3
)
3
), 22.85 (C3''), 25.81 (3C;
), 95.86 (C2), 98.79 (Ar-h-
), 105.34 (Ar-h-C ), 122.43 (2C; C2',
), 129.45 (2C; C3', C5'), 129.64 (ArC ),
t
), 135.52 (C1'), 158.55 (C6), 233.83 (3C; CO);
Reaction of pentacarbonyl{5-(5H)-dibenzo[a.d]cycloheptenylidene}chro-
mium(0) (4) with 4-pentyn-1-ol: The reaction of 4 (1 mmol, 0.38 g) with 4-
pentyn-1-ol (4 mmol, 0.33 g) afforded an orange reaction mixture. Silyla-
tion followed by column chromatographic workup (eluent: petroleum
ether/dichloromethanerˆ 2:1) gave carbene complex 18 (0.09 g,
C(CH
), 99.28 (Ar-h-C
C6'), 127.59 (C4), 128.49 (ArC
30.00 (ArC ), 131.61 (ArC
FT-IR (hexane): nÄ ˆ 1959 (vs, CˆO, A
3
)
3
), 29.80 (C2''), 32.93 (C1''), 55.50 (OCH
3
C
q
q
), 101.93 (Ar-h-C
q
q
t
t
1
t
�
1
), 1892 (s, CˆO, E), 1881 cm (s,
1
0
4
.33 mmol, 33%) and tricarbonyl chromium complex 20 (0.30 g, 0.46 mmol,
‡
‡
CˆO, E); MS (70 eV, EI): m/z (%): 556 (10) [M ], 500 (6) [M � 2CO], 472
6%).
‡
‡
‡
(
C
100) [M � 3CO], 420 (55) [M � Cr(CO)
3
], 363 (22) [M � Cr(CO)
3
�
Tricarbonyl{1-3a:12c-12b-h-[2-(3-tert-butyldimethylsilyloxy)propyl-3-tert-
butyldimethylsilyloxybenzo[4,5]cyclohepta[1,2,3-de]naphthalene]}chromi-
um(0) (20): Red crystals; m.p. 848C (decomp); R
‡
‡
4
H
9
], 306 (27) [M � Cr(CO)
3
� 2C
4
H
H
9
], 126 (30), 73 (23) [Si(CH
3
)
3
], 52
‡
(
(
25) [Cr ]; HR-MS (EI): calcd for C30
10%, [M ]); C30
36CrO
5
Si: 556.1737; found 556.1714
ˆ 0.5 (petroleum ether/
): d ˆ 0.09 (s, 6H;
), 0.93 (s, 9H; C(CH ),
‡
f
H
36CrO
Si (556.59): calcd C 64.73, H 6.52; found C 64.63,
5
1
dichloromethane ˆ 2:1); H NMR (500 MHz, CDCl
3
[41]
H 6.45.
Si(CH
1
1
(
6
7
7
(
3
)
2
), 0.43 (s, 3H; SiCH
3
), 0.44 (s, 3H; SiCH
3
3 3
)
2
,3
.12 (s, 9H; C(CH ), 1.98 (m, 2H; H2'), 2.69 (ddd,
4.62 Hz, 1H; H1'), 2.89 (ddd,
3
)
3
J
HH ˆ 6.66, 9.79,
Acknowledgments: Support by the Fonds der Chemischen Industrie and
the Graduiertenkolleg Spektroskopie isolierter und kondensierter
Moleküle is gratefully acknowledged.
2
,3
J
HH ˆ 5.49, 9.51, 14.62 Hz, 1H; H1'), 3.79
3
m, 2H; H3'), 5.72 (s, 1H; H1), 6.42 (d, JHH ˆ 12.27 Hz, 1H; H7 or H8),
3
3
.52 (d, JHH ˆ 12.27 Hz, 1H; H7 or H8), 7.01 (d, JHH ˆ 6.76 Hz, 1H; ArH),
3
3
.10 (d, JHH ˆ 6.56 Hz, 1H; ArH), 7.20 ± 7.30 (m, 3H; ArH), 7.41 (d, JHH
ˆ
3
13
Received: January 28, 1998 [F977]
.26 Hz, 1H; ArH), 7.66 (d,
J
HH ˆ 8.64 Hz, 1H; ArH);
): d ˆ � 5.26 (SiCH ), � 5.25 (SiCH
3
), 18.39 (C(CH ), 18.87 (C(CH ), 25.94 (3C; C(CH )
C
NMR
125.6 MHz, CDCl
1.99 (SiCH
3
3
3
), � 3.04 (SiCH
3
),
),
�
3
3
)
3
3
)
3
3
2
5.98 (3C; C(CH
), 104.14 (Ar-h-C
), 127.22 (ArC ), 129.26 (ArC
), 131.60 (C3), 131.97 (ArC ), 132.78 (ArC
), 137.31 (ArC ), 137.55 (ArC ), 233.54 (3C; CO); FT-IR (hexane):
), 1897 (s, CˆO, E), 1884 cm (s, CˆO, E); FT-IR
KBr): nÄ ˆ 2963 (m), 2931 (m), 2857 (m), 1950 (vs, CˆO, A ), 1871 (s, CˆO,
E), 1471 (m), 1370 (m), 1258 (m), 1100 (m), 833 (m), 781 cm (m); MS
3
)
3
), 26.77 (C2'), 33.29 (C1'), 62.37 (C3'), 94.53 (C1), 102.41
), 105.53 (Ar-h-C ), 107.05 (Ar-h-C ), 123.37
), 129.74 (ArC ), 130.37 (ArC ), 131.26
), 133.75 (ArC ), 135.99
[
[
1] a) E. O. Fischer, A. Maasböl, Angew. Chem. 1964, 76, 645; Angew.
Chem. Int. Ed. Engl. 1964, 3, 580; b) K. H. Dötz, H. Fischer, P.
Hofmann, F. R. Kreissl, U. Schubert, K. Weiss, Transition Metal
Carbene Complexes, VCH, Weinheim, 1983.
2] a) K. H. Dötz, Angew. Chem. 1984, 96, 573; Angew. Chem. Int. Ed.
Engl. 1984, 23, 587; b) W. D. Wulff, in Comprehensive Organometallic
Chemistry II, Vol. 12 (Eds.: E. W. Abel, F. G. A. Stone, G. Wilkinson),
Pergamon, 1995, pp. 469 ± 547; c) L. S. Hegedus, ibid. Vol. 12, pp. 549 ±
(
(
(
(
Ar-h-C
q
q
q
q
ArC
ArC
ArC
t
t
t
t
t
t
t
t
t
q
q
q
�
1
nÄ ˆ 1959 (vs, CˆO, A
1
(
1
�
1
‡
‡
‡
(
70 eV, EI): m/z (%): 666 (10) [M ], 582 (37) [M � 3CO], 530 (100) [M �
5
76; d) D. F. Harvey, M. Sigano, Chem. Rev. 1996, 96, 271; e) A.
de Meijere, Pure Appl. Chem. 1996, 68, 61; f) J. Barluenga, ibid. 1996,
8, 543.
3] K. H. Dötz, Angew. Chem. 1975, 87, 672; Angew. Chem. Int. Ed. Engl.
975, 14, 644.
4] a) K. H. Dötz, R. Dietz, Chem. Ber. 1978, 111, 2517; b) K. H. Dötz, I.
Pruskil, ibid. 1980, 113, 2876; c) W. D. Wulff, P. C. Tang, J. S.
McCallum, J. Am. Chem. Soc. 1981, 103, 7677; d) K. H. Dötz, J.
Mühlemeier, U. Schubert, O. Orama, J. Organomet. Chem. 1983, 247,
‡
‡
Cr(CO)
2
5
3
], 473 (8) [M � Cr(CO)
3
� C
4
H
9
], 268 (30) [M � Cr(CO)
3
�
‡
tBuMe
2
SiO], 73 (78) [Si(CH
3
)
3
]; HR-MS (EI): calcd for C33
H46CrO
2
Si
2
:
6
‡
82.2441; found 582.2449 (37%, [M � 3CO]); C36
5 2
H46CrO Si (666.93):
[
[
calcd C 64.83, H 7.14; found C 64.63, H 6.95.
1
Reaction of pentacarbonyl[4-methoxyphenyl(phenyl)carbene]chromi-
um(0) (21) with 1-hexyne: The reaction of 21 (1 mmol, 0.39 g) with 1-
hexyne (4 mmol, 0.33 g) afforded an orange solution. Silylation followed by
column chromatographic workup (eluent: petroleum ether/diethyl etherˆ
1
2
87; e) W. D. Wulff, K. S. Chan, P. C. Tang, J. Org. Chem. 1984, 49,
293; f) A. Yamashita, A. Toy, Tetrahedron Lett. 1986, 27, 3471.
3
:1) gave the tricarbonyl chromium complexes 23 (0.14 g, 0.25 mmol, 25%)
and 22 (0.22 g, 0.4 mmol, 40%).
[5] Benzannulation with stannylalkynes shows the reversed regioselec-
Tricarbonyl{1-4a:8a-h-[3-butyl-4-tert-butyldimethylsilyloxy-1-(4'-methoxy)-
phenylnaphthalene]}chromium(0) (22): Red crystals; R
tivity: S. Chamberlain, M. L. Waters, W. D. Wulff, J. Am. Chem. Soc.
f
ˆ 0.4 (petroleum
1
994, 116, 3113.
1
ether/diethyl ether ˆ 3:1); H NMR (500 MHz, CDCl
3
): d ˆ 0.41 (s, 3H;
[
6] a) K. H. Dötz, J. Organomet. Chem. 1977, 140, 177; b) K. H. Dötz, I.
Pruskil, Chem. Ber. 1978, 111, 2059; c) W. D. Wulff, S. R. Gilbertson,
J. P. Springer, J. Am. Chem. Soc. 1986, 107, 5823; d) M. F. Semmelhack,
J. Park, Organometallics 1986, 5, 2550; e) K. E. Garret, J. B. Sheridan,
D. B. Pourreau, W. C. Weng, G. L. Geoffroy, D. L. Staley, A. L.
Rheingold, J. Am. Chem. Soc. 1989, 111, 8383; f) A. Yamashita,
Tetrahedron Lett. 1986, 27, 5915; g) K. H. Dötz, H. Larbig, J.
Organomet. Chem. 1991, 405, C38; h) W. D. Wulff, B. A. Bax, B. A.
Brandvold, K. S. Chan, A. M. Gilbert, R. P. Hsung, J. Mitchell, J.
Clardy, Organometallics 1994, 13, 102.
3
SiCH
SiC(CH
7
OCH
7
8
(
1
(
(
1
(
A
(
3
), 0.45 (s, 3H; SiCH
3
), 0.95 (t, JHH ˆ 7.25 Hz, 3H; H4''), 1.13 (s, 9H;
)
3
), 1.45 (psex, 3JHH ˆ 7.25 Hz, 2H; H3''), 1.64 (pquin,
3
J
HH
ˆ
3
.25 Hz, 2H; H2''), 2.57 (m, 1H; H1''), 2.85 (m, 1H; H1''), 3.91 (s, 3H;
3
3
), 5.75 (s, 1H; H2), 6.95 ± 7.15 (m, 4H; H2', H3', H5', H6'), 7.39 (t, J ˆ
3
3
.65 Hz, 1H; ArH), 7.45 (t,
J
HH ˆ 7.65 Hz, 1H; ArH), 7.75 (d,
J
HH
ˆ
.64 Hz, 1H; ArH), 8.02 (d, 3JHH ˆ 8.64 Hz, 1H; ArH);
13
C NMR
125.6 MHz, CDCl
3
): d ˆ � 3.44 (SiCH
3
), � 2.27 (SiCH
3
), 14.11 (C4''),
), 29.54 (C2''), 32.86
), 101.04 (Ar-h-C ), 105.57
), 113.34 (C1'), 125.46 (ArC ), 126.54 (ArC ),
), 126.65 (ArC ), 128.03 (2C; ArC ), 131.13 (C4), 131.74
), 159.29 (C4'), 233.44 (3C; CO); FT-IR (hexane): nÄ ˆ 1961 (vs, CˆO,
8.78 (C(CH
3
)
3
), 22.95 (C3''), 25.62 (3C; C(CH
), 97.64 (C2), 100.47 (Ar-h-C
), 106.38 (Ar-h-C
26.88 (2C; ArC
ArC
3 3
)
C1''), 55.38 (OCH
Ar-h-C
3
q
q
q
q
t
t
[
7] a) K. H. Dötz, I. Pruskil, J. Organomet. Chem. 1981, 209, C4; b) K. H.
Dötz, I. Pruskil, J. Mühlemeier, Chem. Ber. 1982, 115, 1278; c) K. H.
Dötz, W. Kuhn, Angew. Chem. 1983, 95, 750; Angew. Chem. Int. Ed.
Engl. 1983, 22, 732.
t
t
t
t
�
1
), 1894 (s, CˆO, E), 1884 cm (s, CˆO, E); MS (70 eV, EI): m/z (%): 556
1
‡ ‡ ‡ ‡
20) [M ], 500 (46) [M � 2CO], 472 (100) [M � 3CO], 420 (28) [M �
[8] M. F. Semmelhack, J. J. Bozell, T. Sato, W. D. Wulff, E. Spiess, A.
Zask, J. Am. Chem. Soc. 1982, 104, 5850.
‡
‡
Cr(CO)
2
for C30
(
3
], 363 (18) [M � Cr(CO)
3
� C
4
H
9
], 306 (31) [M � Cr(CO)
3
�
‡
‡
C
4
H
9
], 126 (27), 73 (23) [Si(CH
3
)
3
], 52 (25) [Cr ]; HR-MS (EI): calcd
[
9] a) K. H. Dötz, M. Popall, Angew. Chem. 1987, 99, 1220; Angew.
Chem. Int. Ed. Engl. 1987, 26, 1158; b) W. D. Wulff, Y.-C. Xu, J. Am.
Chem. Soc. 1988, 110, 2312.
‡
H
36CrO
5
Si: 556.1737; found 556.1757 (20%, [M ]); C30
H
36CrO
5
Si
[
41]
556.59): calcd C 64.73, H 6.52; found C 64.63, H 6.45.
Tricarbonyl{1-4a:8a-h-(3-butyl-4-tert-butyldimethylsilyloxy-6-methoxy-1-
[10] a) D. L. Boger, I. C. Jacobsen, J. Org. Chem. 1991, 56, 2115; b) D. L.
Boger, O. Hüter, K. Mbiya, M. Zhang, J. Am. Chem. Soc. 1995, 117,
11839.
[11] H. Fischer, J. Mühlemeier, R. Märkl, K. H. Dötz, Chem. Ber. 1982,
115, 1355.
[12] a) H. C. Foley, L. M. Strubinger, T. S. Targos, G. L. Geoffroy, J. Am.
Chem. Soc. 1983, 105, 3064; b) J. R. Knorr, T. L. Brown, Organo-
metallics 1994, 13, 2178.
phenylnaphthalene)}chromium(0) (23): Red crystals; R
f
ˆ 0.5 (petroleum
1
ether/diethyl ether ˆ 3:1); H NMR (500 MHz, CDCl
3
): d ˆ 0.51 (s, 3H;
3
SiCH
C(CH
3
), 0.55 (s, 3H; SiCH
3
), 0.93 (t, JHH ˆ 7.35 Hz, 3H; H4''), 1.18 (s, 9H;
3
3
3
)
3
), 1.43 (psex, JHH ˆ 7.35 Hz, 2H; H3''), 1.61 (pquin, JHH ˆ 7.87 Hz,
2
3
2
H; H2''), 2.47 (dt,
J
HH ˆ 14.15 Hz,
J
HH ˆ 8.40 Hz, 1H; H1''), 2.78 (dt,
2
3
J
HH ˆ 14.15 Hz, JHH ˆ 8.07 Hz, 1H; H1''), 3.96 (s, 3H; OCH
3
), 5.45 (s, 1H;
3
4
4
H2), 7.04 (dd,
J
HH ˆ 9.38 Hz,
J
HH ˆ 1.96 Hz, 1H; H7), 7.09 (d,
J
HH
ˆ
1
850
ꢀ WILEY-VCH Verlag GmbH, D-69451 Weinheim, 1998
0947-6539/98/0409-1850 $ 17.50+.50/0
Chem. Eur. J. 1998, 4, No. 9

Tetracyclic Arenes
1843±1851
[
[
[
13] K. H. Dötz, T. Schäfer, F. Kroll, K. Harms, Angew. Chem. 1992, 104,
[26] a) J. J. Looker, D. P. Maier, T. H. Regan, J. Org. Chem. 1972, 37, 3401;
b) A. Ebnother, E. Jucker, A. Stoll, Helv. Chim. Acta 1965, 48, 1237;
c) M. Sadek, D. J. Craik, J. G. Hall, P. R. Andrews, J. Med. Chem. 1990,
33, 1098.
[27] For a cyclopropenylium cation derived from a carbene complex, see:
M. Brookhart, M. B. Humphrey, H. J. Kratzer, G. O. Nelson, J. Am.
Chem. Soc. 1980, 102, 7803.
1257; Angew. Chem. Int. Ed. Engl. 1992, 31, 1236.
14] J. Barluenga, F. Aznar, A. Martín, S. García-Granda, E. P e rez-
Carre nÄ o, J. Am. Chem. Soc. 1994, 116, 11191.
15] a) K. H. Dötz, Angew. Chem. 1979, 91, 1021; Angew. Chem. Int. Ed.
Engl. 1979, 18, 954; b) A. Yamashita, T. A. Scahill, Tetrahedron Lett.
1982, 23, 3765; c) B. A. Anderson, J. Bao, T. A. Brandvold, C. A.
Challener, W. D. Wulff, Y.-C. Xu, J. Am. Chem. Soc. 1993, 115, 10671;
d) K. H. Dötz, W. Sturm, J. Organomet. Chem. 1985, 285, 205; e) A.
Mayr, M. F. Asaro, T. J. Glines, J. Am. Chem. Soc. 1987, 109, 2215; f) E.
Chelain, R. Goumont, L. Hamon, A. Parlier, M. Rudler, H. Rudler,
J. C. Daran, J. Vaissermann, J. Am. Chem. Soc. 1992, 114, 8088.
16] a) P. Hofmann, M. Hämmerle, Angew. Chem. 1989, 101, 940; Angew.
Chem. Int. Ed. Engl. 1989, 28, 908; b) P. Hofmann, M. Hämmerle, G.
Unfried, New. J. Chem. 1991, 15, 769.
[28] a) M. J. Aroney, G. M. Hoskins, R. LeFevre, J. Chem. Soc. B 1969,
980; b) S. V. McKinley, P. A. Grieco, A. E. Young, H. H. Freedman, J.
Am. Chem. Soc. 1970, 92, 5900.
[29] a) K. H. Dötz, W. Sturm, H. G. Alt, Organometallics 1987, 6, 1424;
b) F. E. McDonald, C. C. Schultz, J. Am. Chem. Soc. 1994, 116, 9363;
c) A. Segundo, J. M. Moret o , J. M. Vi nÄ as, S. Ricart, Organometallics
1994, 13, 2467.
[30] This explanation is in accordance with a diverse product distribution
observed in the chromium complex catalyzed reactions of various
diazo compounds with electron-rich alkenes: J. Pfeiffer, M. Nieger,
K. H. Dötz, Eur. J. Org. Chem. 1998, 1, 1011.
[31] K. H. Dötz, R. Dietz, Chem. Ber. 1977, 110, 1555.
[32] W. D. Wulff, P.-C. Tang, J. S. McCallum, J. Am. Chem. Soc. 1981, 103,
7677.
[33] G. M. Sheldrick, SHELXTL-Plus, Siemens Analytical X-Ray Instru-
ments, Madison, Wi. (USA), 1989.
[34] G. M. Sheldrick, SHELXTL-93, University of Göttingen, 1993.
[35] N. Walker, D. Stuart, Acta Crystallogr. A 1983, 39, 158.
[36] C. R. Hauser, W. R. Brasen, P. S. Skell, S. W. Kantor, A. E. Brodhag, J.
Am. Chem. Soc. 1956, 78, 1653.
[
[
17] M. M. Gleichmann, K. H. Dötz, B. A. Hess, J. Am. Chem. Soc. 1996,
118, 10551.
[
[
18] J. Möllmann, Ph.D. Thesis, University of Bonn, Bonn, 1997.
19] a) K. H. Dötz, J. Pfeiffer, Chem. Commun. 1996, 895; b) J. Pfeiffer,
K. H. Dötz, Organometallics, in press.
[
20] An orange solid was isolated, the GC-MS of which reveals two
substances with m/z ˆ 228, and two compounds with m/z ˆ 230. The
first are presumed to result from E/Z-1,1'-[bis-(1H)-indenylidene],
whereas the structures of the last two compounds remain unclear.
21] A. C. Hazell, Acta Crystallogr. B 1978, 34, 3037.
[
[
22] For the assignment of helical chiral enantiomers see: a) R. S. Cahn,
C. K. Ingold, V. Prelog, Angew. Chem. 1966, 78, 413; Angew. Chem.
Int. Ed. Engl. 1966, 5, 385; b) R. H. Martin, G. Morren, J. J. Schurter,
Tetrahedron Lett. 1969, 10, 3683. For the assignment of planar chiral
enantiomers see: K. Schlögl, Top. Curr. Chem. 1984, 125, 27.
23] K. Brandenburg, M. Berndt, DIAMOND, University of Bonn, Bonn,
[37] Assigned on the basis of a HHCOSY experiment.
[38] Assigned on the basis of a CHCOSY experiment.
[39] No analytically pure samples of compounds 13 and 19 could be
obtained. Partial decomposition occurred within several hours at
� 388C.
[
1995.
[
[
24] A. Solladi e -Cavallo, Polyhedron 1985, 4, 901.
25] K. H. Dötz, G. Huttner, R. Dietz, A. von Imhof, H. Lorenz, Chem.
Ber. 1976, 109, 2033.
[40] C7 and C8 have been assigned on the more pronounced temperature
dependence of the signal broadening in case of C8.
[41] Mixture of 22 and 23.
Chem. Eur. J. 1998, 4, No. 9
ꢀ WILEY-VCH Verlag GmbH, D-69451 Weinheim, 1998
0947-6539/98/0409-1851 $ 17.50+.25/0
1851