New building blocks based on truxene cores: Synthesis of functionalized syn-tri- and -hexasubstituted derivatives

Article abstract of DOI:10.1002/ejoc.200500260

Hexasubstituted truxenes are obtained in one step by alkylation of the potassium anion of truxene. Subsequent derivatization provides truxene derivatives with six carboxy, amino, or hydroxy groups at their peripheries. Alkylation of syn-5,10,15-tribenzyl derivatives with a different benzyl bromide derivative affords mixtures of anti- and syn-hexasubstituted truxenes. Truxenes with phenols or benzoquinone groups have also been synthesized by starting from truxenetrione. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.

Full text of DOI:10.1002/ejoc.200500260

FULL PAPER
New Building Blocks Based on Truxene Cores: Synthesis of Functionalized
syn-Tri- and -Hexasubstituted Derivatives
Esther González-Cantalapiedra,[a] Marta Ruiz,[b] Berta Gómez-Lor,[b] Beatriz Alonso,[c]
Domingo García-Cuadrado,[d] Diego J. Cárdenas,[a] and Antonio M. Echavarren*[a,d]
Keywords: Arenes / Strained molecules / Truxenes / Isomerization / Quinones
Hexasubstituted truxenes are obtained in one step by alky-
lation of the potassium anion of truxene. Subsequent derivati-
zation provides truxene derivatives with six carboxy, amino, or
hydroxy groups at their peripheries. Alkylation of syn-5,10,15-
tive affords mixtures of anti- and syn-hexasubstituted trux-
enes. Truxenes with phenols or benzoquinone groups have
also been synthesized by starting from truxenetrione.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
tribenzyl derivatives with a different benzyl bromide deriva- Germany, 2005)
Table 1. Synthesis of symmetrical hexasubstituted benzyltruxenes
5a–j.
Introduction
Truxene (10,15-dihydro-5H-diindeno[1,2-a;1Ј,2Ј-c]fluo-
rene (1, see Scheme 1) has been used for the construction
of larger polyarenes[1–5] and for the synthesis of new materi-
als.[6–9] For the synthesis of polyarenes with the topology of
the fullerenes,[10–12] we have previously developed a synthe-
sis of derivatives 3 based on treatment of the trianion of 1
with a variety of alkylating agents followed by anti to syn
Scheme 1.
[a] Departamento de Química Orgánica, Universidad Autónoma
de Madrid,
Cantoblanco, 28049 Madrid, Spain
[b] Instituto de Ciencia de Materiales de Madrid (ICMM),
Cantoblanco, 28049 Madrid, Spain
[c] Departamento de Química Inorgánica, Universidad Autónoma
de Madrid,
[a] This yield refers to the two-step alkylation.
Cantoblanco, 28049 Madrid, Spain
[d] Institute of Chemical Research of Catalonia (ICIQ),
43007 Tarragona, Spain
isomerization with KOtBu in tBuOH (Scheme 1).[13,14] We
also reported that syn-5,10,15-triaryltruxenes 2 (R = aryl)
Fax: +34-977920225
E-mail: aechavarren@iciq.es
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DOI: 10.1002/ejoc.200500260
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A. M. Echavarren et al.
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can be obtained from truxenetrione 4 by addition of arylli- to furnish 5,5,10,10,15,15-hexasubstituted truxenes 5a–j in
thium compounds, reduction of the alcohols with Et3SiH moderate to good yields (Table 1). The synthesis of hexaal-
and BF3, and anti to syn equilibration.[15]
kylated truxenes with nBuLi (7 equiv.) as the base was also
Here we report a one-pot synthesis of 5,5,10,10,15,15- assayed, but mixtures of syn- and anti-trialkylated truxenes
hexasubstituted derivatives by simple alkylation of 1 in the were obtained.[9] Some hexasubstituted derivatives of trux-
presence of excess of base. Several sterically crowded deriva- ene were synthesized in two steps by initial preparation of
tives can be readily prepared by this method. We also report syn-trialkylated truxenes 3 and subsequent deprotonation
the synthesis of new derivatives substituted at their periph- with KOtBu (3 equiv.) and addition of RX, but yields were
eries with carboxy, amino, or hydroxy groups. A derivative lower by this method. Alkylation with 9-(3-bromopropyl)
bearing three benzoquinone units as well as the truxene anthracene[17] failed to provide the corresponding hexasub-
scaffold has also been synthesized. These derivatives could stituted derivative, and instead gave 9-(prop-1-enyl)anthra-
be useful as core structures for the synthesis of dendrimers, cene and a mixture of unidentified truxenes.
as well as in molecular tectonics and for the building of
Derivative 5a is almost insoluble in common NMR sol-
vents and could be characterized only by FAB mass spec-
trometry. Similarly, treatment of 1 with 2-(bromomethyl)
benzonitrile gave a bluish solid (in ca. 60% yield) that could
not be characterized due to its insolubility in all solvents.
Interestingly, nitriles 5e and 5f are blue in solution and in
the solid state. Crystals of nitriles 5e and 5f could be grown
from DMF/Et2O solution, and their X-ray diffraction
complex supramolecular structures.[16]
Results and Discussion
Synthesis of Hexabenzyltruxenes by Alkylation
Treatment of truxene (1) with KOtBu (6 equiv.) gives a structures show the benzyl groups generally approximately
green suspension corresponding to a mixture of deproton- perpendicular to the central truxene plane (Figure 1), al-
ated species, which reacts with a variety of alkyl halides though one of the benzyl groups in derivative 5f adopts a
Figure 1. X-ray diffraction structures of nitriles 5e (a) and 5f (b).
Figure 2. PM3 minimum structure for 5h.
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New Building Blocks Based on Truxene Cores
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different conformation as the crystal shelters a disordered Table 2. Synthesis of asymmetrical hexabenzyltruxenes.
DMF molecule.
It is interesting to note that the chemical shifts of the
truxene hydrogen signals in the hexaalkylated truxenes are
concentration-independent in all cases, in contrast with
what has been observed with syn-trialkylated derivatives
3,[13] which indicates that hexasubstitution inhibits the self-
association. The 1H NMR spectrum of hexakis(9-an-
thracenyl)methyltruxene 5h shows signals for Ha (δ = 4.57
ppm) and Hb (δ = 5.39 ppm) shifted upfield relative to
those of other truxene derivatives. This effect is the result
of the shielding of the hydrogen atoms of the truxene scaf-
fold by the two nearly perpendicular anthracenyl systems,
as shown in the PM3-minimized structure of 5h (Figure 2).
Truxenes with different substituents at their benzylic po-
sitions can be obtained by treatment of syn-trialkylated
truxenes with KOtBu in THF, followed by the addition of
alkyl halides to give 1.5:1 to 2:1 mixtures of anti- (6) and
syn-hexaalkylated (7) truxenes in very good yields (Table 2).
The syn/anti ratios were determined by 1H NMR in the
crude reaction mixtures. Hexaalkylated truxenes 6 and 7
CDCl3 at room temperature, while the resonances were still
could be separated by flash column chromatography.
not well resolved in 1,1,2,2-tetrachloro[D2]ethane at 110 °C.
The structure of 9 was confirmed by its esterification with
MeOH and H2SO4 under reflux to give hexaester 10, show-
ing the expected NMR spectroscopic data, in 74% yield.
Synthesis of Symmetrical Hexaalkyltruxenes by
Functionalization in the Side Chains
Triptycenes have attracted interest as “spacers” providing
Reduction of hexacyano derivative 5e with LiAlH4 in crystalline compounds containing channels capable of oc-
THF gave the hexaamine 8 in 51% yield (Scheme 2). Com- cluding a variety of other molecules.[18] In consequence, we
pound 5e also reacted with NaOH in aqueous MeOH under decided to synthesize a triptycene derivative from hexaan-
reflux to give derivative 9 in 78% yield. This hexacarboxylic thracenyltruxene 5h by treatment with anthranilic acid and
1
acid shows very broad signals in the H NMR spectrum in isoamyl nitrite in 1,2-dichloroethane and benzene under re-
Scheme 2.
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A. M. Echavarren et al.
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flux.[19,20] However, the resulting yellow solid product could triallyltruxene 11[13a] was allowed to react with catecholbo-
not be characterized, due to its extraordinarily low solubil- rane in THF under reflux, followed by oxidative workup,
ity.
to give trialcohol 12 in 60% yield (Scheme 3). Similarly, 5i
The synthesis of a truxene with six hydroxy substituents was converted into the hexahydroxy derivative 13, albeit in
was carried out from compound 5i. Firstly, as a model, syn- lower overall yield. As would be expected from the hydro-
Scheme 3.
Scheme 4.
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New Building Blocks Based on Truxene Cores
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philic periphery of 13, this truxene is more soluble in [D4]
MeOH than in CDCl3.
Synthesis of Functionalized syn-Triaryltruxenes
The synthesis of truxenes bearing phenol groups at posi-
tions 5, 10, and 15 was carried out by the general approach
developed for the preparation of overcrowded syn-5,10,15-
trisubstituted truxenes.[15b] Thus, truxenetrione 4 was al-
lowed to react with the corresponding aryllithium reagents
to give mixtures of anti (14a–d) and syn (15a–d) derivatives
(Scheme 4). Reduction of the resulting benzylic alcohols
with Et3SiH and BF3·OEt2 afforded ca. 3–10:1 mixtures of
anti (16a–d) and syn (17a–d) derivatives. Finally, base-cata-
lyzed isomerization of anti isomers 16a–c furnished pure
syn-5,10,15-truxenes 17a–c.
Correspondingly, demethylation of compounds 17a and
17b with BBr3 in CH2Cl2 at –78 °C provided triphenols 18a
and 18b in 62–72% yields. No isomerization to the anti de-
rivatives was observed under these conditions. Demethyl-
ation of a 10:1 mixture of 16c and 17c gave a 10:1 mixture
of syn-18c and anti-19c. Phenols 18a–c are soluble in
1
MeOH and acetone. The H NMR spectra of 18b and 18c
showed concentration-dependent chemical shifts for the
benzylic hydrogen signals, which is characteristic of self-as-
sociation of syn-5,10,15-trisubstituted truxenes.[13] In con-
trast, the 1H NMR spectrum of 18a was not concentration-
dependent (Scheme 5).
Scheme 5.
Oxidation of a mixture of 16d and 17d with ceric ammo-
nium nitrate (CAN) or phenyliodonium bis(trifluoroacet-
ate) (PIFA) failed to give quinones 20 or 21. However, de-
methylation of 16d and 17d provided 18d and 19d, respec-
tively, in satisfactory yields (Scheme 6). These tris(hydroqui-
nones) were oxidized with PIFA in a mixture of MeOH and
CH2Cl2 to give anti-20 and syn-21 as orange compounds.
Cyclic voltammetry of 20 and 21 (Figure 3) showed two
reversible reduction waves corresponding to the formation
nificant difference in the reduction potentials of stereoiso-
mers 20 and 21 was observed, and they are also very similar
to those of 2-methyl- and 2-phenyl-1,4-benzoquinones
(Table 3).
Summary
Simple alkylation of the potassium anion of truxene with
of the radical anion and the hydroquinone anion. No sig- alkyl halides affords hexasubstituted truxenes in one step.
Scheme 6.
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A. M. Echavarren et al.
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well as 3a–c and 11[13] were prepared by the described procedures.
General Procedure for the Synthesis of 5,5Ј,10,10Ј,15,15Ј-Hexaalkyl-
10,15-dihydro-5H-diindeno[1,2-a;1Ј,2Ј-c]fluorenes:
A mixture of
truxene (1, 0.58 mmol) and KOtBu (3.48 mmol) in THF (20 mL)
was heated under reflux for 30 min. The alkyl bromide (3.48 mmol)
in THF (10 mL) was then added to the green suspension. After
16 h, the mixture was cooled and diluted with CH2Cl2, washed with
saturated aqueous NaCl solution, and dried (Na2SO4), and the sol-
vents were evaporated. The residue was usually triturated with
CH2Cl2 to give pure 5a–i.
5,5,10,10,15,15-Hexakis(phenylmethyl)-10,15-dihydro-5H-diindeno-
[1,2-a;1Ј,2Ј-c]fluorene (5a): In this case, the solid was filtered off
and washed with CH2Cl2, acetone, and Et2O to give 5a (436 mg,
86%); white solid; m.p. Ͼ300 °C. FAB-MS: m/z (%) = 921 (48)
[M + K]+. HR-FAB-MS: m/z for C69H54K: calcd. 921.3863; found
921.3868.
Figure 3. Cyclic voltammogram of tris(quinones) 20 (---) and 21
(−) (room temperature, in CH2Cl2 solutions containing 0.1 
TBAPF6 as a supporting electrolyte; scan rate = 100 mV·s–1).
5,5,10,10,15,15-Hexakis[(2-bromophenyl)methyl]-10,15-dihydro-5H-
diindeno[1,2-a;1Ј,2Ј-c]fluorene (5b): Yellow solid (440 mg, 56%):
m.p. Ͼ300 °C; Rf = 0.18 (10:1 hexane/CH2Cl2). H NMR (CDCl3,
Table 3. Reduction potentials of 20, 21 and reference compounds.
1
Quinone
Solvent, electrolyte E0 [V] E0
300 MHz): δ = 4.17 (d, J = 13.7 Hz, 6 H), 4.30 (d, J = 13.7 Hz, 6
H), 6.49 (d, J = 6.1 Hz, 6 H), 6.59 (t, J = 7.3 Hz, 6 H), 6.70 (t, J
= 8.1 Hz, 6 H), 7.07 (t, J = 7.7 Hz, 3 H), 7.21–7.25 (m, 9 H), 7.38
(d, J = 8.1 Hz, 3 H), 8.36 (d, J = 7.7 Hz, 3 H) ppm. 13C NMR
(CDCl3, 75 MHz): δ = 40.27 (2 C), 56.74, 124.91, 125.64, 126.00,
126.25, 126.73, 127.62, 129.96, 132.44, 137.52, 146.28, 148.93 (se-
veral signals were not observed) ppm. FAB-MS: m/z (%) = 1395
(34) [M + K]+. HR-FAB-MS: m/z for C69H4879Br381Br3K: calcd.
1394.8448; found 1394.8432.
I
II
[V]
20
CH2Cl2, (TBA)
PF6
CH2Cl2, (TBA)
PF6
CH2Cl2, (TBA)
PF6
MeCN, TEAP
–0.94
–0.95
–0.89
–1.04
–0.95
–1.51
21
–1.53
–1.80
–1.58
–1.57
1,4-Benzoquinone[21]
2-Methyl-1,4-benzoqui-
none[22]
2-Phenyl-1,4-benzoqui-
MeCN, TEAP
5,5,10,10,15,15-Hexakis[(3-bromophenyl)methyl]-10,15-dihydro-5H-
diindeno[1,2-a;1Ј,2Ј-c]fluorene (5c): The residue was triturated with
Et2O to give 5c (638 mg, 81%); yellow solid; m.p. 140–141 °C; Rf
= 0.36 (3:1 hexane/CH2Cl2). 1H NMR (CDCl3, 300 MHz): δ = 3.50
(d, J = 13.3 Hz, 6 H), 3.85 (d, J = 13.3 Hz, 6 H), 6.04 (d, J =
7.9 Hz, 6 H), 6.63 (t, J = 7.9 Hz, 6 H), 6.76 (m, 6 H), 7.04 (dd, J
= 8.1, 1.0 Hz, 6 H), 7.22 (dd, J = 7.5, 1.2 Hz, 3 H), 7.40 (t, J =
7.5 Hz, 3 H), 7.48 (t, J = 7.3 Hz, 3 H), 8.40 (d, J = 8.1 Hz, 3 H)
ppm. 13C NMR (CDCl3, 125 MHz, DEPT): δ = 40.50 (2 CH2),
56.85 (C), 121.12 (C), 125.26 (CH), 125.95 (CH), 126.30 (CH),
127.42 (CH), 128.17 (2 CH), 128.94 (CH), 129.08 (CH), 133.31
(CH), 138.52 (C), 139.09 (C), 139.43 (C), 144.35 (C), 145.51 (C)
(several signals were not observed, due to overlapping) ppm.
MALDI-MS (dithranol + AgTFA): m/z (%) = 1395 (20)
[M + K]+, 1465 (100) [M + Ag]+. HR-MALDI-MS: m/z for
C69H4879Br381Br3K: calcd. 1394.8448; found 1394.8483.
none[23]
Further derivatization gives rise to truxene derivatives with
six carboxy, amino, or hydroxy groups at their peripheries,
which could be useful as scaffolds for the construction of
larger structures. As expected, alkylation of syn-5,10,15-tri-
benzyl derivatives with a different benzyl bromide affords
mixtures of anti- and syn-hexasubstituted truxenes that can
be separated by chromatography. Furthermore, truxenes
bearing three pendant phenol, anisole, and benzoquinone
units at C5, C10, and C15 have also been synthesized, by
starting from truxenetrione. Oxidation of tris(hydroqui-
none) derivatives affords the corresponding anti- and syn-
tris(benzoquinone) derivatives, which show similar re-
duction potentials.
5,5,10,10,15,15-Hexakis[(4-bromophenyl)methyl]-10,15-dihydro-5H-
diindeno[1,2-a;1Ј,2Ј-c]fluorene (5d): Yellow solid (721 mg, 92%):
1
m.p. Ͼ300 °C; Rf = 0.35 (2:1 hexane/CH2Cl2). H NMR (CDCl3,
300 MHz): δ = 3.41 (d, J = 13.7 Hz, 6 H), 3.87 (d, J = 13.7 Hz, 6
H), 6.03 (d, J = 8.4 Hz, 12 H), 6.92 (d, J = 8.1 Hz, 12 H), 7.40–
7.48 (m, 9 H), 8.39 (d, J = 8.9 Hz, 3 H) ppm. 13C NMR (CDCl3,
75 MHz): δ = 40.95 (2 C), 57.17, 120.02, 130.53, 131.39, 135.75
(several signals were not observed) ppm. APCI-MS: m/z (%) = 1357
(60) [M + 1]+.
Experimental Section
General Remarks: The NMR spectra were determined at 23 °C,
unless otherwise stated. The FAB-MS were obtained with m-ni-
trobenzyl alcohol as the matrix. Only the most significant MS frag-
mentations are given. Rf values were determined on TLC alumin-
ium sheets coated with 0.2 mm GF254 silica gel. All reactions were
carried out under Ar. Solvents were purified and dried by standard
methods. The saturated aqueous NH4Cl solution was buffered with
NH4OH (pH = 8). Chromatographic purifications were carried out
with flash grade silica gel. “Usual workup” means pouring the
crude reaction mixture into saturated aqueous NH4Cl solution, fol-
lowed by extraction with the stated solvent, drying (MgSO4), and
evaporation of the solvent. Truxene (1) and truxenetrione 4,[24] as
5,5,10,10,15,15-Hexakis[(3-cyanophenyl)methyl]-10,15-dihydro-5H-
diindeno[1,2-a;1Ј,2Ј-c]fluorene (5e): The residue was purified by
flash chromatography (CH2Cl2) and was then triturated with Et2O
to give 5e (450 mg, 75%); blue solid; m.p. 154–156 °C; Rf = 0.14
1
(CH2Cl2). H NMR (CDCl3, 300 MHz): δ = 3.56 (d, J = 13.3 Hz,
6 H), 3.86 (d, J = 13.3 Hz, 6 H), 6.33 (dt, J = 8.1, 1.2 Hz, 6 H),
6.80 (t, J = 1.6 Hz, 6 H), 6.88 (t, J = 8.1 Hz, 6 H), 7.23 (dt, J =
7.7, 1.2 Hz, 9 H), 7.46 (t, J = 7.7 Hz, 3 H), 7.52 (td, J = 7.7, 1.2 Hz,
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New Building Blocks Based on Truxene Cores
3 H), 8.36 (d, J = 7.7 Hz, 3 H) ppm. 13C NMR (CDCl3, 75 MHz): δ (6a) and 5α,10α,15α-Tris[(2-bromophenyl)methyl]-5β,10β,15β-tris[(3-
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= 40.60 (2 C), 56.70, 111.44, 118.50, 125.25, 125.81, 127.31, 128.23,
130.10, 133.45, 138.05, 138.44, 138.86, 143.82, 148.82 (several sig-
nals were not observed, due to overlapping) ppm. FAB-MS: m/z
(%) 1071 (100) [M + K]+, 1033 (15) [M + 1]+. HR-FAB-MS: m/z
methoxyphenyl)methyl]-10,15-dihydro-5H-diindeno[1,2-a;1Ј,2Ј-c]fluo-
rene (7a): A mixture of 5,10,15-tris(2-bromophenylmethyl)-10,15-
dihydro-5H-diindeno[1,2-a;1Ј,2Ј-c]fluorene (3a, 80 mg, 0.09 mmol)
and KOtBu (34 mg, 0.28 mmol) in THF (10 mL) was heated under
for C75H49N6: calcd. 1033.4019; found 1033.4037; for C75H48N6K: reflux for 30 min. 3-Methoxybenzyl bromide (62 mg, 0.31 mmol) in
calcd. 1071.3602; found 1071.3577.
THF (5 mL) was then added to the green suspension. After 16 h,
the mixture was cooled to 23 °C and diluted with CH2Cl2, washed
with saturated aqueous NaCl solution, and dried (Na2SO4). The
solvent was evaporated and the residue was triturated with hexane
to yield a ca. 2:1 mixture of anti-6a and syn-7a. The mixture of
isomers could be separated by flash column chromatography (hex-
ane/CH2Cl2, 1:1). anti-6a: 77 mg, 68 %; yellow solid; m.p. 200–
201 °C; Rf = 0.32 (1:1 hexane/CH2Cl2). 1H NMR (CDCl3,
300 MHz): δ = 3.28 (s, 3 H), 3.34 (s, 3 H), 3.48 (s, 3 H), 3.52–4.03
(m, 8 H), 4.08 (d, J = 15.4 Hz, 1 H), 4.18 (d, J = 14.8 Hz, 1 H),
4.32 (d, J = 12.1 Hz, 1 H), 4.46 (d, J = 13.1 Hz, 1 H), 5.42 (d, J =
7.7 Hz, 1 H), 5.62 (dd, J = 7.9, 1.8 Hz, 1 H), 5.90 (d, J = 1.6 Hz,
2 H), 6.06 (d, J = 7.5 Hz, 1 H), 6.18–6.27 (m, 3 H), 6.42 (dd, J =
13.9, 7.7 Hz, 2 H), 6.56–6.68 (m, 2 H), 6.81–7.11 (m, 5 H), 7.51
(dd, J = 7.9, 1.4 Hz, 1 H), 7.17–7.44 (m, 14 H), 7.59 (d, J = 6.5 Hz,
1 H), 8.43 (dd, J = 7.5, 4.6 Hz, 3 H) ppm. 13C NMR (CDCl3,
75 MHz, DEPT): δ = 39.23 (CH2), 39.31 (CH2), 39.61 (CH2), 42.34
(CH2), 42.45 (CH2), 42.81 (CH2), 54.58 (CH3), 54.70 (CH3), 54.78
(CH3), 56.88 (C), 57.13 (C), 57.14 (C), 111.68 (CH), 111.83 (CH),
112.02 (CH), 115.07 (CH), 115.12 (CH), 115.42 (CH), 121.88 (CH),
121.97 (CH), 122.33 (CH), 124.83 (CH), 124.95 (CH), 125.02 (CH),
125.53 (C), 125.61 (CH), 125.70 (CH), 125.80 (CH), 125.91 (C),
126.33 (CH), 126.58 (CH), 126.75 (CH), 127.18 (CH), 127.46 (CH),
127.56 (CH), 127.72 (CH), 128.21 (CH), 129.91 (CH), 130.88 (CH),
131.85 (CH), 132.25 (CH), 132.61 (CH), 137.28 (C), 137.85 (C),
137.93 (C), 138.42 (C), 138.51 (C), 138.57 (C), 138.89 (C), 139.00
(C), 139.25 (C), 145.24 (C), 145.36 (C), 145.57 (C), 149.75 (C),
149.90 (C), 157.85 (C), 158.13 (C), 158.49 (C) (several signals were
not observed, due to overlapping) ppm. MALDI-MS (AgTFA):
m/z = 1317 [M + Ag]+. HR-MALDI-MS: m/z for C72H57107Ag79-
Br3O3: calcd. 1313.0908; found 1313.0903. syn-7a: 33 mg, 29%; yel-
low solid; m.p. 140–141 °C; Rf = 0.19 (hexane/CH2Cl2, 1:1). 1H
NMR (CDCl3, 300 MHz): δ = 3.44 (s, 9 H), 3.63 (d, J = 13.3 Hz,
3 H), 3.98 (d, J = 13.1 Hz, 3 H), 4.10 (d, J = 14.3 Hz, 3 H), 4.30
(d, J = 14.6 Hz, 3 H), 5.76 (d, J = 7.7 Hz, 3 H), 6.18 (t, J = 1.6 Hz,
3 H), 6.45 (dd, J = 7.9, 1.8 Hz, 3 H), 6.54 (td, J = 7.3, 1.2 Hz, 6
H), 6.71 (td, J = 8.1, 1.8 Hz, 3 H), 6.74 (t, J = 7.9 Hz, 3 H), 7.21–
7.42 (m, 12 H), 8.42 (d, J = 7.7 Hz, 3 H) ppm. 13C NMR (CDCl3,
75 MHz, DEPT): δ = 38.82 (CH2), 43.12 (CH2), 54.86 (CH3), 56.87
(C), 111.97 (CH), 115.65 (CH), 122.33 (CH), 125.03 (CH), 125.55
(CH), 125.77 (C), 125.83 (CH), 126.25 (CH), 126.61 (CH), 127.37
(CH), 128.27 (CH), 129.60 (CH), 132.33 (CH), 137.98 (C), 138.22
(C), 138.74 (C), 138.86 (C), 145.57 (C), 149.71 (C), 158.26 (C) ppm.
MALDI-MS (AgTFA): m/z = 1317 [M + Ag]+. HR-MALDI-MS:
m/z for C72H57107Ag79Br3O3: calcd. 1313.0908; found 1313.0903.
5,5,10,10,15,15-Hexakis[(4-cyanophenyl)methyl]-10,15-dihydro-5H-
diindeno[1,2-a;1Ј,2Ј-c]fluorene (5f): The solid was filtered off and
washed with CH2Cl2, acetone, and Et2O to give 5f (566 mg, 94%);
1
blue solid; m.p. Ͼ300 °C; Rf = 0.08 (CH2Cl2). H NMR (1,1,2,2-
tetrachloro[D2]ethane, 300 MHz, 80 °C): δ = 3.52 (d, J = 12.8 Hz,
6 H), 3.85 (d, J = 12.8 Hz, 6 H), 6.34 (d, J = 6.5 Hz, 12 H), 7.04
(d, J = 5.7 Hz, 12 H), 7.24 (d, J = 7.7 Hz, 3 H), 7.39 (t, J = 7.3 Hz,
3 H), 7.47 (t, J = 6.9 Hz, 3 H), 8.27 (d, J = 7.3 Hz, 3 H) ppm. 13C
NMR (1,1,2,2-tetrachloro[D2]ethane, 125 MHz, 80 °C): δ = 29.88,
41.91, 110.85, 115.01, 130.65, 131.25, 139.65, 142.40, 172.23 (se-
veral signals were not observed) ppm. FAB-MS: m/z (%) = 1071
(100) [M + K]+, 1033 (8) [M + 1]+. MALDI-MS (dithranol): m/z =
1071 [M + K]+. HR-FAB-MS: m/z for C75H49N6: calcd. 1033.4019;
found 1033.4029; for C75H48N6K: calcd. 1071.3571; found
1071.3577.
5,5,10,10,15,15-Hexakis(2-methylanthracenyl)-10,15-dihydro-5H-di-
indeno[1,2-a;1Ј,2Ј-c]fluorene (5g): The residue was purified by flash
chromatography (hexane/CH2Cl2, 2:1) and was then triturated with
Et2O to give 5g (313 mg, 37%); yellow solid; m.p. 200–201 °C; Rf
= 0.10 (2:1 hexane/CH2Cl2). 1H NMR (CDCl3, 300 MHz): δ = 3.68
(d, J = 13.3 Hz, 6 H), 4.06 (d, J = 13.3 Hz, 6 H), 6.09 (dd, J = 8.9,
1.6 Hz, 6 H), 6.36 (d, J = 8.9 Hz, 6 H), 7.24 (s, 3 H), 7.26–7.45 (m,
27 H), 7.57 (s, 3 H), 7.72–7.81 (m, 12 H), 8.03 (s, 6 H), 8.58 (d, J
= 8.1 Hz, 3 H) ppm. 13C NMR (CDCl3, 75 MHz): δ = 41.83, 57.53
(2 C), 124.79, 124.99, 125.30, 125.50, 125.74, 125.92, 125.96,
126.11, 126.62, 127.01, 127.73, 127.99, 128.11, 128.47, 129.49,
130.23, 130.26, 130.29, 130.33, 130.49, 130.77, 131.16, 131.38,
131.41, 131.45, 131.48, 131.80, 134.61, 134.66, 134.75, 134.79,
138.85, 139.69, 145.01, 150.50, 150.53 ppm. FAB-MS: m/z (%) =
1483 (18) [M + 1]+. HR-FAB-MS: m/z for C117H79: calcd.
1483.6161; found 1483.6181.
5,5,10,10,15,15-Hexakis(9-methylanthracenyl)-10,15-dihydro-5H-di-
indeno[1,2-a;1Ј,2Ј-c]fluorene (5h): Yellow solid (647 mg, 75%): m.p.
1
249–250 °C; Rf = 0.30. H NMR (CDCl3, 300 MHz): δ = 4.57 (d,
J = 7.3 Hz, 3 H), 4.86 (d, J = 14.6 Hz, 6 H), 5.39 (t, J = 7.3 Hz, 3
H), 5.58 (d, J = 14.6 Hz, 6 H), 6.88 (t, J = 7.3 Hz, 3 H), 7.05–7.18
(m, 24 H), 7.80–7.77 (m, 15 H), 8.17 (s, 6 H), 8.75–7.94 (m, 9 H),
8.98 (d, J = 8.1 Hz, 3 H) ppm. 13C NMR (CDCl3, 75 MHz): δ =
34.86, 60.18, 123.77, 125.11, 125.52, 126.03, 127.06, 129.46, 131.85,
132.27, 133.47, 138.91 (the rest of signals were not observed) ppm.
MALDI-MS (dithranol): m/z = 1482 [M]+.
5,5,10,10,15,15-Hexakis(3-buten-1-yl)-10,15-dihydro-5H-diindeno-
[1,2-a;1Ј,2Ј-c]fluorene (5i): The residue was purified by flash
chromatography (hexane/CH2Cl2, 8.5:1.5) to give 5i (283 mg, 83%);
white solid; m.p. 162–163 °C; Rf = 0.30 (hexane/CH2Cl2, 8.5:1.5).
1H NMR (CDCl3, 400 MHz): δ = 2.95 (dd, J = 13.6, 7.2 Hz, 6 H),
3.66 (dd, J = 13.6, 7.6 Hz, 6 H), 4.44 (dd, J = 10.4, 2.0 Hz, 6 H),
4.51 (dd, J = 17.2, 1.6 Hz, 6 H), 4.92–5.02 (m, 6 H), 7.37–7.45 (m,
6 H), 7.56 (dd, J = 7.2, 1.6 Hz, 3 H), 8.32 (d, J = 7.2 Hz, 3 H)
ppm. 13C NMR (CDCl3, 100 MHz, APT): δ = 39.82 (CH2), 55.15
(C), 116.76 (CH2), 123.08 (CH), 124.99 (CH), 126.36 (CH), 126.39
(CH), 133.29 (CH), 138.24 (C), 139.76 (C), 143.83 (C), 151.95 (C)
ppm. MALDI-MS: m/z = 582 [M]+.
5α,10α,15β-Tris(3-bromophenylmethyl)-5β,10β,15α-tris[(3-meth-
oxyphenyl)methyl]-10,15-dihydro-5H-diindeno[1,2-a;1Ј,2Ј-c]fluorene
(6a) and 5α,10α,15α-Tris(3-bromophenylmethyl)-5β,10β,15β-tris[(3-
methoxyphenyl)methyl]-10,15-dihydro-5H-diindeno[1,2-a;1Ј,2Ј-c]fluo-
rene (7b): A mixture of 5,10,15-tris(3-bromophenylmethyl)-10,15-
dihydro-5H-diindeno[1,2-a;1Ј,2Ј-c]fluorene (3b, 200 mg,
0.24 mmol) and KOtBu (87 mg, 0.71 mmol) in THF (20 mL) was
heated under reflux for 30 min. 3-Methoxybenzyl bromide (157 mg,
0.78 mmol) in THF (10 mL) was then added to the green suspen-
sion. After 16 h, the mixture was cooled to 23 °C and diluted with
CH2Cl2, washed with saturated aqueous NaCl solution, and dried
5α,10α,15β-Tris[(2-bromophenyl)methyl]-5β,10β,15α-tris[(3-meth-
oxyphenyl)methyl]-10,15-dihydro-5H-diindeno[1,2-a;1Ј,2Ј-c]fluorene (Na2SO4). The solvent was evaporated and the residue was tritu-
Eur. J. Org. Chem. 2005, 4127–4140
www.eurjoc.org © 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 4133

A. M. Echavarren et al.
FULL PAPER
rated with hexane to yield a ca. 1.5:1 mixture of anti-6b and syn-
7b. The mixture of isomers could be separated by flash column
chromatography (1:1 hexane/CH2Cl2). anti-6b: 190 mg, 66%; yel-
(CH2), 54.81 (CH2), 54.95 (CH2), 57.00 (CH2), 57.22 (CH2), 57.26
(CH2), 111.44 (CH), 111.50 (C), 111.55 (C), 111.59 (C), 115.62
(CH), 115.93 (CH), 116.38 (CH), 119.47 (C), 119.63 (C), 119.84
low solid; m.p. 166–167 °C; Rf = 0.38 (1:1 hexane/CH2Cl2). 1H (C), 122.09 (CH), 122.23 (CH), 122.51 (CH), 125.19 (CH), 125.26
NMR (CDCl3, 300 MHz): δ = 3.43–3.54 (m, 4 H), 3.56 (s, 3 H), (CH), 125.51 (CH), 125.58 (CH), 125.76 (C), 125.82 (CH), 125.86
3.58 (s, 3 H), 3.60 (s, 3 H), 3.63–3.77 (m, 4 H), 3.84 (d, J = 13.4 Hz, (CH), 125.90 (CH), 126.92 (CH), 128.19 (CH), 128.56 (CH), 128.62
1 H), 3.94 (d, J = 13.4 Hz, 1 H), 4.05 (d, J = 13.4 Hz, 1 H), 4.11
(d, J = 13.4 Hz, 1 H), 5.99 (d, J = 7.7 Hz, 1 H), 5.85 (dd, J = 10.7, (C), 131.37 (C), 131.41 (CH), 135.94 (C), 136.04 (C), 136.09 (C),
7.7 Hz, 3 H), 6.08 (d, J = 7.5 Hz, 2 H), 6.27 (s, 2 H), 6.35 (s, 1 H), 138.59 (C), 138.70 (C), 138.76 (C), 138.80 (C), 139.47 (C), 139.58
6.55 (td, J = 6.3, 2.6 Hz, 3 H), 6.62 (t, J = 7.9 Hz, 3 H), 6.75 (d, J (C), 139.61 (C), 144.03 (C), 144.15 (C), 144.47 (C), 149.94 (C),
= 17.6 Hz, 3 H), 6.82 (d, J = 7.7 Hz, 2 H), 6.89 (t, J = 7.9 Hz, 1 150.04 (C), 150.08 (C), 158.32 (C), 158.36 (C), 158.57 (C); (several
(CH), 130.08 (C), 130.13 (CH), 130.46 (CH), 130.50 (CH), 131.31
H), 7.02 (dd, J = 16.4, 8.1 Hz, 2 H), 7.30–7.52 (m, 10 H), 8.48 (d, signals were not observed, due to overlapping) ppm. MALDI-MS
J = 7.7 Hz, 3 H) ppm. 13C NMR (CDCl3, 75 MHz): δ = 40.05,
40.44, 40.53, 41.20, 41.39, 41.48, 54.86, 54.91 (2 C), 56.91, 56.99,
(AgTFA): m/z = 1317 [M + Ag]+. HR-MALDI-MS: m/z for
C
72H57107Ag79Br3O3: calcd. 1313.0908; found 1313.0903. syn-7c:
57.03, 111.65, 111.81, 115.89, 116.03, 116.20, 120.27, 120.73, 54 mg, 38 %; yellow solid; m.p. 153–154 °C; Rf = 0.43 (hexane/
120.87, 122.20, 122.43, 122.50, 122.53, 122.57, 125.21, 125.25, CH2Cl2, 1:1). 1H NMR (CDCl3, 300 MHz): δ = 3.38–3.49 (m, 6
125.81, 125.89, 125.95, 126.92, 126.95, 127.79, 128.02, 128.07, H), 3.58 (s, 9 H), 5.90 (d, J = 7.5 Hz, 3 H), 4.29 (d, J = 13.3 Hz, 6
128.26, 128.35, 128.39, 128.61, 128.76, 128.81, 128.85, 133.07, H), 6.00 (d, J = 8.3 Hz, 6 H), 6.26 (s, 3 H), 6.53 (dd, J = 8.3,
133.17, 138.43, 138.51, 138.54, 138.64, 138.75, 139.38, 139.43, 2.4 Hz, 3 H), 6.79 (t, J = 7.5 Hz, 3 H), 6.92 (d, J = 8.3 Hz, 6 H),
139.53, 139.61, 139.70, 144.52, 144.68, 144.63, 149.86, 149.90, 7.33–7.48 (m, 9 H), 8.48 (d, J = 7.5 Hz, 3 H) ppm. 13C NMR
158.40, 158.44, 158.52 (several signals were not observed, due to
overlapping) ppm. MALDI-MS (AgTFA): m/z = 1317 [M + Ag]+.
HR-MALDI-MS: m/z for C72H57107Ag79Br3O3: calcd. 1313.0908;
found 1313.0903. syn-7b: 95 mg, 33 %; yellow solid; m.p. 143–
(CDCl3, 75 MHz, DEPT): δ = 40.38 (CH2), 41.77 (CH2), 54.93
(CH3), 57.21 (C), 111.57 (CH), 116.38 (CH), 119.67 (C), 122.42
(CH), 125.25 (CH), 125.68 (CH), 125.82 (CH), 126.95 (CH), 128.25
(CH), 130.48 (CH), 131.29 (CH), 131.33 (C), 136.07 (C), 138.62
144 °C; Rf = 0.16 (1:1 hexane/CH2Cl2). 1H NMR (CDCl3, (C), 138.85 (C), 139.54 (C), 144.22 (C), 149.97 (C), 158.47 (C) (se-
300 MHz): δ = 3.53 (br.s, 9 H), 3.54–3.60 (m, 6 H), 3.82–3.95 (m,
6 H), 5.78 (d, J = 7.5 Hz, 3 H), 6.13 (d, J = 7.8 Hz, 3 H), 6.20
veral signals were not observed, due to overlapping) ppm. MALDI-
MS (AgTFA): m/z = 1317 [M + Ag]+. HR-MALDI-MS: m/z for
(br.s, 3 H), 6.52 (d, J = 8.1 Hz, 3 H), 6.70 (t, J = 7.8 Hz, 3 H), C72H57107Ag79Br3O3: calcd. 1313.0908; found 1313.0903.
6.85 (br.s, 3 H), 6.73 (t, J = 7.8 Hz, 3 H), 7.10 (d, J = 8.1 Hz, 3
5,5,10,10,15,15-Hexakis{[3-(aminomethyl)phenyl]methyl}-10,15-di-
hydro-5H-diindeno[1,2-a;1Ј,2Ј-c]fluorene (8): Truxene 5e (100 mg,
0.29 mmol) in THF (12 mL) was slowly added at 0 °C to a suspen-
sion of LiAlH4 (121 mg, 3.19 mmol) in THF (6 mL), and the mix-
ture was then heated under reflux for 16 h. After the mixture had
been cooled to 0 °C, H2O was added very slowly, together with an
aqueous solution of HCl, and the mixture was extracted with
CH2Cl2. The aqueous layer was basified with an aqueous solution
of NaOH and extracted with CH2Cl2 and dried (MgSO4), and the
solvents were evaporated. The blue oil was triturated with CHCl3/
Et2O (1:100) to give 8 (156 mg, 51%); blue solid; m.p. Ͼ300 °C; Rf
= 0.14 (CH2Cl2). 1H NMR (CDCl3, 300 MHz): δ = 3.54 (s, 12 H),
3.55 (d, J = 13.4 Hz, 6 H), 3.84 (d, J = 13.4 Hz, 6 H), 6.00 (d, J =
7.3 Hz, 3 H), 6.55 (s, 6 H), 6.78 (t, J = 7.7 Hz, 6 H), 6.86 (d, J =
7.5 Hz, 6 H), 7.34–7.46 (m, 12 H), 8.48 (d, J = 7.7 Hz, 3 H) ppm.
13C NMR (CDCl3, 75 MHz, DEPT): δ = 40.95 (2 CH2), 46.31 (2
CH2), 57.16 (C), 124.50 (2 CH), 125.21 (2 CH), 126.21 (CH),
126.48 (CH), 127.50 (2 CH), 128.04 (2 CH), 129.06 (2 CH), 137.47
(2 C), 138.30 (C), 139.69 (C), 142.07 (2 C), 144.85 (C), 150.29 (C)
ppm. MALDI-MS (DHB/MeOH): m/z = 1057 [M + 1]+. HR-
MALDI-MS: m/z for C75H73N6: calcd. 1057.5891; found
1057.5880.
H), 7.32 (dd, J = 7.3, 2.4 Hz, 3 H), 7.42 (t, J = 7.1 Hz, 3 H), 7.50
(t, J = 7.1 Hz, 3 H), 8.49 (d, J = 7.8 Hz, 3 H) ppm. 13C NMR
(CDCl3, 75 MHz): δ = 40.77, 40.97, 54.84, 56.93, 111.68, 116.07,
120.99, 122.24, 125.22, 125.79, 125.86, 126.94, 127.84, 128.32,
128.79, 128.89, 133.29, 138.41, 138.53, 139.39, 139.86, 144.61,
149.89, 158.36 ppm. MALDI-MS (AgTFA): m/z = 1317 [M + Ag]+.
HR-MALDI-MS: m/z for C72H57107Ag79Br3O3: calcd. 1313.0908;
found 1313.0903.
5β,10β,15α-Tris(4-bromophenylmethyl)-5α,10α,15β-tris[(3-meth-
oxyphenyl)methyl]-10,15-dihydro-5H-diindeno[1,2-a;1Ј,2Ј-c]fluorene
(6c) and 5β,10β,15β-Tris(4-bromophenylmethyl)-5α,10α,15α-tris[(3-
methoxyphenyl)methyl]-10,15-dihydro-5H-diindeno[1,2-a;1Ј,2Ј-c]fluo-
rene (7c): A mixture of 5,10,15-tris(4-bromophenylmethyl)-10,15-
dihydro-5H-diindeno[1,2-a;1Ј,2Ј-c]fluorene (3c, 100 mg,
0.12 mmol) and KOtBu (43 mg, 0.35 mmol) in THF (10 mL) was
heated under reflux for 30 min. 3-Methoxybenzyl bromide (78 mg,
0.39 mmol) in THF (5 mL) was then added to the green suspen-
sion. After 16 h, the mixture was cooled to 23 °C and diluted with
CH2Cl2, washed with saturated aqueous NaCl solution, and dried
(Na2SO4). The solvent was evaporated and the residue was tritu-
rated with hexane to yield a ca. 1.5:1 mixture of anti-6c and syn-
7c. The mixture of isomers could be separated by flash column
chromatography (hexane/CH2Cl2 1:1). anti-6c: 87 mg, 61%; yellow
solid; m.p. 130–131 °C; Rf = 0.33 (hexane/CH2Cl2, 1:1). H NMR 5H-diindeno[1,2-a;1Ј,2Ј-c]fluorene (9): NaOH (25% aq, 32 mL) was
(CDCl3, 300 MHz): δ = 3.50 (s, 3 H), 3.53 (s, 3 H), 3.34–3.59 (m, added to a solution of 5e (400 mg, 0.39 mmol) in MeOH (40 mL)
5,5,10,10,15,15-Hexakis[(3-carboxyphenyl)methyl]-10,15-dihydro-
1
8 H), 3.64 (s, 3 H), 3.87–3.95 (m, 2 H), 4.07 (d, J = 13.5 Hz, 1 H),
and the mixture was heated under reflux for 16 h. After being co-
4.20 (d, J = 13.1 Hz, 1 H), 5.72 (d, J = 7.7 Hz, 1 H), 5.84 (d, J = oled, the mixture was poured into HCl solution (10%) and the
7.7 Hz, 1 H), 6.02 (dd, J = 13.3, 8.5 Hz, 5 H), 6.12 (s, 2 H), 6.14 solid was filtered off and washed with CH2Cl2. The aqueous layer
(d, J = 6.2 Hz, 2 H), 6.34 (s, 1 H), 6.50 (dd, J = 7.9, 2.0 Hz, 1 H),
was extracted CH2Cl2 and dried (Na2SO4), the solvent was evapo-
6.62 (ddd, J = 15.8, 7.9, 2.0 Hz, 2 H), 6.75 (dd, J = 15.8, 7.9 Hz, rated, and the residue was triturated with acetone/Et2O to yield 9
2 H), 6.83 (dd, J = 10.5, 8.3 Hz, 4 H), 6.92 (t, J = 7.9 Hz, 2 H),
6.99 (d, J = 8.3 Hz, 2 H), 7.33–7.48 (m, 8 H), 8.46 (dd, J = 7.1,
6.2 Hz, 3 H) ppm. 13C NMR (CDCl3, 75 MHz, DEPT): δ = 40.26
(349 mg, 78%); green solid; m.p. 284–286 °C. 1H NMR (1,1,2,2-
tetrachloro[D2]ethane, 110 °C, 300 MHz): δ = 3.57–4.40 (m, 12 H),
6.70–7.70 (m, 33 H), 8.00–8.10 (m, 3 H) ppm. 13C NMR (1,1,2,2-
(CH3), 40.93 (CH3), 41.19 (CH3), 41.54 (2 CH3), 41.60 (CH3), 54.79 tetrachloro[D2]ethane, 75 MHz, DEPT, 110 °C): δ = 29.69 (CH2),
4134 © 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim www.eurjoc.org
Eur. J. Org. Chem. 2005, 4127–4140

New Building Blocks Based on Truxene Cores
FULL PAPER
30.03 (CH2), 73.88 (CH), 74.53 (CH) (several signals were not ob- 128.28, 140.32, 141.12, 145.60, 154.22 ppm. 13C NMR ([D4]MeOH,
served) ppm. MALDI-MS (DHB/MeOH): m/z = 1147 [M + 1]+.
100 MHz, DEPT): δ = 28.78 (CH2), 34.32 (CH2), 56.30 (C), 63.22
(CH2), 123.84 (CH), 126.09 (CH), 127.71 (CH), 128.28 (CH),
140.32 (C), 141.12 (C), 145.60 (C), 154.22 (C) ppm. HR-EI-MS:
m/z for C45H54NaO6: calcd. 713.3818; found 713.3827.
5,5,10,10,15,15-Hexakis{[3-(methoxycarbonyl)phenyl]methyl}-
10,15-dihydro-5H-diindeno[1,2-a;1Ј,2Ј-c]fluorene (10): H2SO4 (96%,
0.5 mL) was added to a solution of 9 (26 mg, 0.02 mmol) in MeOH
(6 mL) and the mixture was heated under reflux for 16 h. After
having been cooled, the mixture was diluted with H2O, extracted
with CH2Cl2, and dried (Na2SO4). The solvent was evaporated and
the residue was chromatographed (hexane/EtOAc, 2:1) to give 10
(21 mg, 74%); white solid; m.p. 138–139 °C; Rf = 0.16 (hexane/
EtOAc, 2:1). 1H NMR (CDCl3, 300 MHz): δ = 3.47–3.77 (m, 6 H),
3.78 (s, 3 H), 3.79 (s, 3 H), 3.80 (s, 3 H), 3.81 (s, 3 H), 3.82 (s, 3
H), 3.83 (s, 3 H), 3.84–4.06 (m, 6 H), 6.15–6.42 (m, 6 H), 6.71–6.97
(m, 9 H), 7.16–7.52 (m, 15 H), 7.60–7.71 (m, 3 H), 8.38–8.52 (m,
3 H) ppm. 13C NMR (CDCl3, 75 MHz, DEPT): δ = 40.64 (CH2),
40.74 (CH2), 51.85 (CH3), 51.91 (CH3), 56.60 (C), 56.68 (C), 56.82
(C), 56.92 (C), 110.88 (C), 118.56 (C), 125.22 (CH), 125.34 (CH),
125.63 (CH), 125.81 (CH), 125.92 (CH), 126.05 (CH), 126.60 (CH),
126.78 (CH), 127.13 (CH), 127.30 (CH), 127.95 (CH), 128.03 (CH),
128.91 (CH), 128.99 (CH), 129.11 (CH), 129.51 (CH), 131.47 (CH),
133.60 (CH), 133.70 (CH), 133.89 (CH), 134.02 (CH), 134.10 (CH),
137.07 (C), 137.19 (C), 137.34 (C), 137.43 (C), 138.49 (C), 138.55
(C), 138.69 (C), 138.75 (C), 149.14 (C), 149.47 (C), 149.61 (C),
166.74 (C) (several signals were not observed, due to overlapping)
ppm. MALDI-MS (dithranol + NaI): m/z = 1253 [M + Na]+. HR-
MALDI-MS: m/z for C81H66NaO12: calcd. 1253.4442; found
1253.4446.
5α,10α,15β-Trihydroxy-5β,10β,15α-tris(2-methoxyphenyl)-10,15-di-
hydro-5H-diindeno[1,2-a;1Ј,2Ј-c]fluorene (14a) and 5α,10α,15α-Tri-
hydroxy-5β,10β,15β-tris(2-methoxyphenyl)-10,15-dihydro-5H-di-
indeno[1,2-a;1Ј,2Ј-c]fluorene (15a): nBuLi (5.6 mL, 14.06 mmol,
2.5  in hexane) was added at –78 °C to a solution of 2-bromoani-
sole (1.75 mL, 14.06 mmol) in Et2O (10 mL). The mixture was
warmed up to 10 °C and then a suspension of truxenetrione 4
(600 mg, 1.56 mmol) in THF (50 mL) was added. The mixture was
stirred at room temperature for 3 h. After aqueous workup, extrac-
tion with EtOAc, and drying with MgSO4, the solvent was evapo-
rated and the residue was triturated with hexane to give a ca. 1:2.8
mixture of 14a and 15a (1.06 g, 96%) as a gray solid. The mixture
was separated by column chromatography (CH2Cl2/EtOAc, 30:1).
14a: White solid; m.p. 234–236 °C; Rf = 0.39 (CH2Cl2/EtOAc,
20:1). 1H NMR (CDCl3, 300 MHz): δ = 4.00 (br.s, 9 H), 6.67–6.75
(m, 3 H), 6.96–7.10 (m, 9 H), 7.14–7.22 (m, 3 H), 7.56–7.75 (m, 9
H) ppm. 1H NMR ([D6]DMSO, 300 MHz): δ = 3.16 (br.s, 9 H),
6.14 (s, 1 H, OH), 6.18 (s, 1 H, OH), 6.22 (s, 1 H, OH), 6.73 (m, 3
H), 6.92–7.03 (m, 12 H), 7.09–7.16 (m, 6 H), 7.84–7.95 (m, 3 H)
ppm. 13C NMR ([D6]DMSO, 75 MHz): δ = 55.26, 55.90, 56.04,
81.70 (br), 112.35, 113.38, 113.66, 120.02, 120.44, 123.01, 123.09,
123.20, 125.68, 125.77, 125.93, 126.66, 126.77, 127.08, 127.16,
127.66, 127.72, 128.17, 128.28, 128.36, 132.66, 133.21, 137.68 (br),
138.88 (br), 144.48 (br), 151.15, 151.34, 151.79, 156.61, 156.78,
157.12, 157.17 (some signals were not observed, due to overlap-
5α,10α,15α-Tris(3-hydroxypropyl)-10,15-dihydro-5H-diindeno[1,2-
a;1Ј,2Ј-c]fluorene (12): Catecholborane (0.90 mL, 8.43 mmol) was
added very slowly at 0 °C to a mixture of 11 (325 mg, 0.703 mmol)
in THF (10 mL), and the mixture was stirred under reflux for 16 h.
After the mixture had been cooled to 0 °C, a solution of THF/
EtOH (1:1) (12 mL), NaOH (12 mL, 2 ), and H2O2 (12 mL) was
added. The mixture was extracted with CH2Cl2, washed with
NaOH solution (1 ), and dried (MgSO4). The solvent was evapo-
rated and the residue was triturated with CH2Cl2 to give 11
(218 mg, 60%); yellow solid; m.p. 241–242 °C; Rf = 0.17 (CH2Cl2/
EtOAc, 1:2). 1H NMR (CDCl3, 300 MHz): δ = 0.74–0.80 (m, 3 H),
0.95–1.05 (m, 3 H), 1.61 (br.s, 3 H), 2.15–2.24 (m, 3 H), 2.33–2.45
(m, 3 H), 2.96–3.16 (m, 6 H), 4.48 (t, J = 4.1 Hz, 3 H), 7.43 (t, J
= 7.1 Hz, 3 H), 7.36 (t, J = 7.1 Hz, 3 H), 7.55 (d, J = 7.1 Hz, 3 H),
7.85 (d, J = 7.5 Hz, 3 H) ppm. 13C NMR (CDCl3, 75 MHz,
DEPT): δ = 27.11 (CH2), 27.25 (CH2), 46.08 (CH), 62.69 (CH2),
122.63 (CH), 124.84 (CH), 126.55 (CH), 127.07 (CH), 136.80 (C),
140.43 (C), 140.82 (C), 147.99 (C) ppm. MALDI-MS (dithranol +
AgTFA): m/z = 539 [M + Na]+. HR-MALDI-MS: m/z for
C36H36NaO3: calcd. 539.2562; found 539.2557.
ping) ppm. IR: ν = 3485, 3056, 3928, 1594, 1596, 1483, 1274, 1228,
˜
1040, 1020, 742 cm–1. EI-MS: m/z (%) = 708 (100) [M]+, 691 (18),
674 (9), 601 (19), 583 (8). HRMS: m/z for C48H36O6: calcd.
708.2512; found 708.2508. 15a: White solid; m.p. Ͼ300 °C. Rf =
0.05 (CH2Cl2/EtOAc, 20:1). 1H NMR (CDCl3, 300 MHz): δ = 3.69
(br.s, 9 H), 6.90 (br.s, 4 H), 7.01–7.11 (m, 8 H), 7.16–7.22 (m, 4 H),
1
7.47 (br.s, 4 H), 7.75–7.77 (m, 4 H) ppm. H NMR ([D6]DMSO,
200 MHz): δ = 3.12 (br.s, 9 H), 6.19 (s, 1 H, OH), 6.79 (br.s, 3 H),
6.99–7.03 (m, 12 H), 7.12–7.19 (m, 6 H), 7.97 (br.s, 3 H) ppm. 13
C
NMR (CDCl3, 75 MHz): δ = 55.44, 81.58, 112.83, 120.22, 122.93,
125.92, 126.87, 127.18, 127.62, 128.46, 129.10, 132.56, 137.73,
138.53, 151.72, 156.85 ppm. EI-MS: m/z (%) = 708 (43) [M]+, 691
(100), 674 (10). IR: ν = 3552, 3484, 1730, 1600, 1584, 1490, 1242,
˜
1047, 755, 644 cm–1. HRMS: m/z for C48H36O6: calcd. 708.2512;
found 708.2512.
5α,10α,15β-Trihydroxy-5β,10β,15α-tris(3-methoxyphenyl)-10,15-di-
hydro-5H-diindeno[1,2-a;1Ј,2Ј-c]fluorene (14b) and 5α,10α,15α-Tri-
hydroxy-5β,10β,15β-tris(3-methoxyphenyl)-10,15-dihydro-5H-di-
indeno[1,2-a;1Ј,2Ј-c]fluorene (15b): nBuLi (6.16 mL, 15.6 mmol,
2.5  in hexane) was added at –78 °C to a solution of 3-bromoani-
5,5,10,10,15,15-Hexakis(3-hydroxypropyl)-10,15-dihydro-5H-di-
indeno[1,2-a;1Ј,2Ј-c]fluorene (13): Catecholborane (1  in THF,
9.68 mL, 9.68 mmol) was added slowly at 0 °C to a mixture of 5i sole (1.98 mL, 15.6 mmol) in THF (20 mL). The mixture was
(235 mg, 0.403 mmol) in THF (10 mL), and the resulting mixture
was stirred under reflux for 16 h. After the mixture had been cooled
to 0 °C, a solution of THF/EtOH (1:1, 10 mL), NaOH (10 mL,
2 ), and H2O2 (10 mL) was added. The mixture was extracted with
CH2Cl2 and washed with NaOH solution (1 ). The organic layer
was concentrated and the residue was triturated with CH2Cl2
(5 mL) and filtered. The filtrate was washed with water and acetone
to give 13 (84 mg, 30%); white solid; m.p. 246–248 °C; Rf = 0.40
warmed up to 10 °C and a suspension of truxenetrione 4 (1.00 g,
2.6 mmol) in THF (80 mL) was then added. The mixture was
stirred at room temperature for 17 h. After aqueous workup, ex-
traction with EtOAc, and drying with MgSO4, the solvent was
evaporated and the residue was triturated with hexane to give a ca.
1.1:1 mixture of 14b and 15b (1.20 g, 65%) as a yellow solid. The
mixture was separated by column chromatography (CH2Cl2/
EtOAc, 40:1). 14b: Yellow solid; m.p. 176–178 °C; Rf = 0.66
1
(CH2Cl2/MeOH, 9:1). 1H NMR ([D4]MeOH, 400 MHz): δ = 0.73– (CH2Cl2/EtOAc, 20:1). H NMR (CDCl3, 200 MHz): δ = 2.80 (s,
0.84 (m, 12 H), 2.28–2.32 (m, 6 H), 3.03–3.16 (m, 18 H), 7.44 (br.s,
2 H), 2.81 (s, 1 H), 3.69 (s, 6 H), 3.73 (s, 3 H), 6.67–6.72 (m, 3 H),
6 H), 7.59 (br.s, 3 H), 8.44 (br.s, 3 H) ppm. 13C NMR (CD3OD, 7.06–7.23 (m, 15 H), 7.31–7.37 (m, 3 H), 7.83–7.87 (m, 3 H) ppm.
100 MHz): δ = 28.78, 34.32, 56.30, 63.22, 123.84, 126.09, 127.71, 13C NMR (CDCl3, 75 MHz): δ = 55.05, 55.08, 55.19, 83.50, 83.67,
Eur. J. Org. Chem. 2005, 4127–4140
www.eurjoc.org
© 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
4135

A. M. Echavarren et al.
FULL PAPER
83.83, 110.86, 111.00, 111.55, 111.83, 112.31, 112.50, 123.52, of truxenetrione 4 (1.20 g, 3.13 mmol) in THF (120 mL) was then
123.72, 123.91, 126.23, 126.31, 126.48, 128.68–128.48 (m, 9 C), added. The mixture was stirred at room temperature for 3 h. After
129.54, 130.19, 135.93, 136.01, 136.07, 143.20, 143.29, 143.99, aqueous workup, extraction with EtOAc, and drying with MgSO4,
151.07, 151.30, 151.58, 159.64, 159.69 (some signals were not ob- the solvent was evaporated and the residue was triturated with hex-
served, due to overlapping) ppm. IR: ν = 3478, 3440, 3072, 2932,
ane to give a ca. 1:1.1 mixture of 14d and 15d (2.25 g, 90%) as a
yellow solid. The mixture was separated by column chromatog-
raphy (CH2Cl2/EtOAc, 30:1). 14d: Pale yellow solid; m.p. 194–
196 °C; Rf = 0.68 (CH2Cl2/EtOAc, 15:1). 1H NMR (CDCl3,
300 MHz): δ = 3.53 (br.s, 9 H), 3.87 (br.s, 9 H), 6.64–6.70 (m, 3
H), 6.88 (br.s, 3 H), 7.02–7.14 (m, 9 H), 7.58 (br.s, 3 H), 7.75–7.78
(m, 3 H) ppm. 1H NMR ([D6]acetone, 300 MHz): δ = 2.81 (s, 3 H),
˜
2836, 1701, 1602, 1584, 1486, 1460, 1280, 1246, 1147, 1042, 760,
746, 698 cm–1. EI-MS: m/z (%) = 708 (100) [M]+, 601 (84), 493 (29),
385 (21), 357 (19). HRMS: m/z for C48H36O6: calcd. 708.2512;
found 708.2516. 15b: White solid; m.p. 264–266 °C; Rf = 0.18
1
(CH2Cl2/EtOAc, 20:1). H NMR (CDCl3, 200 MHz): δ = 2.79 (s,
3 H), 3.62 (s, 9 H), 6.60–6.66 (m, 3 H), 6.88 (br.s, 3 H), 6.98–7.06
(m, 6 H), 7.10–7.15 (m, 6 H), 7.197.24 (m, 3 H), 7.75–7.79 (m, 3 3.63 (br.s, 18 H), 5.64 (br.s, 3 H), 6.64–6.71 (m, 3 H), 6.81 (br.s, 3
H) ppm. 13C NMR (CDCl3, 75 MHz): δ = 54.82, 83.32, 110.41,
H), 6.94–7.04 (m, 6 H), 7.34 (br.s, 3 H), 7.91–8.04 (m, 3 H) ppm.
112.56, 117.16, 123.27, 126.28, 128.46, 128.62, 129.38, 135.57, 13C NMR (CDCl3, 75 MHz): δ = 55.41, 55.58, 55.66, 56.39, 56.54,
139.50, 143.32, 143.68, 151.13, 159.50 ppm. IR: ν = 3556, 3530,
56.70, 84.11, 84.52, 85.10, 112.88, 113.05, 113.48, 122.75, 122.83,
127.83, 127.91, 128.15, 128.18, 132.15 (br), 137.10 (br), 138.50,
139.63 (br), 142.39, 151.28, 151.35, 151.53, 153.85, 153.99 (some
˜
3470, 3072, 2932, 2838, 1608, 1588, 1480, 1454, 1292, 1250, 762,
702 cm–1. EI-MS: m/z (%) = 708 (100) [M]+, 601 (73.2), 493 (11),
385 (13), 345 (18). HRMS: m/z for C48H36O6: calcd. 708.2512;
found 708.2518.
signals were not observed, due to overlapping) ppm. IR: ν = 3484,
˜
1606, 1584, 1496, 1222, 1040, 1028, 744 cm–1. EI-MS: m/z (%) =
798 (100) [M]+, 781 (14), 764 (3), 750 (2), 661 (8), 643 (10). HRMS:
m/z for C51H42O9: calcd. 798.2829; found 798.2824. 15d: Pale yel-
low solid; m.p. 184–186 °C; Rf = 0.14 (CH2Cl2/EtOAc, 15:1). 1H
NMR (CDCl3, 300 MHz): δ = 3.53 (br.s, 9 H), 3.87 (br.s, 9 H),
6.64–6.70 (m, 3 H), 6.88 (br.s, 3 H), 7.02–7.14 (m, 9 H), 7.58 (br.s,
5α,10α,15β-Trihydroxy-5β,10β,15α-tris(4-methoxyphenyl)-10,15-di-
hydro-5H-diindeno[1,2-a;1Ј,2Ј-c]fluorene (14c) and 5α,10α,15α-Tri-
hydroxy-5β,10β,15β-tris(4-methoxyphenyl)-10,15-dihydro-5H-di-
indeno[1,2-a;1Ј,2Ј-c]fluorene (15c): nBuLi (11.25 mL, 28.13 mmol,
2.5  in hexane) was added at –78 °C to a solution of 4-bromoani-
sole (3.53 mL, 28.13 mmol) in Et2O (20 mL). The mixture was
warmed up to 15 °C and a suspension of truxenetrione 4 (1.20 g,
3.13 mmol) in THF (120 mL) was then added. The mixture was
stirred at room temperature for 3 h. After aqueous workup, extrac-
tion with EtOAc, and drying with MgSO4, the solvent was evapo-
rated and the residue was triturated with hexane to give a ca. 2:1
mixture of 14c and 15c (2.11 g, 95%) as a white solid. The mixture
was separated by column chromatography (CH2Cl2/EtOAc, 20:1).
14c: White solid; m.p. 222–224 °C; Rf = 0.77 (CH2Cl2/EtOAc,
20:1). 1H NMR (CDCl3, 300 MHz): δ = 2.67 (s, 1 H), 2.68 (s, 1
H), 2.73 (s, 1 H), 3.71 (s, 3 H), 3.72 (s, 6 H), 6.18–6.74 (m, 6 H),
7.05–7.16 (m, 6 H), 7.32–7.35 (m, 3 H), 7.45–7.55 (m, 6 H), 7.77–
7.83 (m, 3 H) ppm. 13C NMR (CDCl3, 75 MHz): δ = 55.02, 83.30,
83.47, 83.58, 113.76, 113.87, 123.41, 123.66, 126.03, 126.28, 126.36,
126.60, 128.37, 128.43, 134.31, 135.71, 135.82, 139.50, 139.61,
139.78, 143.35, 143.43, 143.44, 151.41, 151.66, 151.80, 158.55,
158.72 (some signals were not observed, due to overlapping) ppm.
1
3 H), 7.75–7.78 (m, 3 H) ppm. H NMR ([D6]acetone, 300 MHz):
δ = 2.79 (s, 3 H), 3.65 (br.s, 18 H), 5.57 (s, 3 H), 6.68 (dd, J = 8.9,
2.8 Hz, 3 H), 6.84 (br.s, 3 H), 6.98–7.36 (m, 6 H), 7.36 (br.s, 3 H),
8.01 (br.s, 3 H) ppm. 13C NMR ([D6]acetone, 75 MHz): δ = 55.82,
56.96, 83.70, 113.16, 114.83, 123.68, 127.27, 128.05, 128.19, 134.16,
138.71, 139.60, 144.37, 152.48, 152.90, 154.66 (some signals were
not observed, due to overlapping) ppm. IR: ν = 3484, 1606, 1581,
˜
1496, 1218, 1037, 744, 734 cm–1. EI-MS: m/z (%) = 798 (100)
[M]+, 781 (14), 764 (4), 750 (4), 661 (8), 643 (6). HRMS: m/z for
C51H42O9: calcd. 798.2829; found 798.2830.
5α,10α,15β-Tris(2-methoxyphenyl)-10,15-dihydro-5H-diindeno[1,2-
a;1Ј,2Ј-c]fluorene (16a) and 5α,10α,15α-Tris(2-methoxyphenyl)-
10,15-dihydro-5H-diindeno[1,2-a;1Ј,2Ј-c]fluorene (17a): Et3SiH
(2.67 mL, 16.81 mmol) and BF3·OEt2 (1.33 mL, 10.57 mmol) were
added at 0 °C to a mixture of 14a and 15b (480 mg, 0.68 mmol) in
CH2Cl2 (15 mL). The mixture was stirred at 0 °C for 45 min and
was then partitioned between a saturated aqueous NH4Cl solution
(pH = 7 with NH4OH) and CH2Cl2. After extractive workup, the
residue was triturated with EtOAc to give a ca. 2.6:1 mixture of
16a and 17a as a yellow solid (309 mg, 70%). The mixture was
separated by column chromatography (hexane/CH2Cl2, 2:1). 16a:
Yellow solid; m.p. Ͼ300 °C; Rf = 0.73 (hexane/CH2Cl2, 1:1). 1H
NMR (CDCl3, 300 MHz): δ = 4.19 (br.s, 9 H), 6.26–6.38 (m, 4 H),
6.50–6.63 (m, 5 H), 7.06–7.13 (m, 12 H), 7.38–7.46 (m, 6 H) ppm.
13C NMR (CDCl3, 75 MHz): δ = 46.35, 55.76, 55.79, 110.65,
110.76, 121.23 (br), 122.77, 122.85, 124.41, 124.54, 126.45, 126.55,
126.62, 127.60, 127.66, 129.68, 129.75, 129.91, 138.09, 139.10,
139.83, 139.99, 149.62, 149.71, 149.81, 157.14, 157.20 (some signals
were not observed, due to overlapping) ppm. EI-MS: m/z (%) =
660 (100) [M]+, 552 (20), 445 (17). HRMS: m/z for C48H36O3: calcd.
660.2664; found 660.2677. 17b: Yellow solid; m.p. Ͼ300 °C; Rf =
IR: ν = 3542, 3442, 1700, 1602, 1576, 1502, 1465, 1242, 1164, 1020,
˜
820, 742, 576 cm–1. EI-MS: m/z (%) = 708 (100) [M]+, 690 (43), 601
(44), 493 (22), 385 (12), 357 (12). HRMS: m/z for C48H36O6: calcd.
708.2512; found 708.2513. 15c: White solid; m.p. Ͼ300 °C; Rf =
0.14 (CH2Cl2/EtOAc, 20:1). 1H NMR ([D6]acetone, 300 MHz): δ =
2.79 (s, 3 H), 3.65 (s, 9 H), 6.78 (d, J = 8.9 Hz, 6 H), 7.00–7.11 (m,
6 H), 7.26 (d, J = 8.1 Hz, 3 H), 7.50 (d, J = 8.9 Hz, 6 H), 8.11 (d,
J = 6.9 Hz, 3 H) ppm. 13C NMR ([D6]acetone, 75 MHz): δ = 55.29,
83.91, 114.36, 124.26, 126.97, 127.80, 128.25, 128.47, 136.70,
137.45, 140.16, 145.62, 153.54, 159.51 ppm. IR: ν = 3556, 1600,
˜
1582, 1514, 1462, 1300, 1249, 1164, 1027, 830, 754 cm–1. EI-MS:
m/z (%) = 708 (100) [M]+, 692 (44), 676 (28),660 (53), 601 (36), 568
(16), 552 (20), 493 (14), 445 (10), 357 (6). HRMS: m/z for
C48H36O6: calcd. 708.2512; found 708.2524.
1
0.58 (hexane/CH2Cl2, 1:1). H NMR (CDCl3, 300 MHz): δ = 4.16
5α,10α,15β-Trihydroxy-5β,10β,15α-tris(2,5-dimethoxyphenyl)-10,15-
dihydro-5H-diindeno[1,2-a;1Ј,2Ј-c]fluorene (14d) and 5α,10α,15α-
Trihydroxy-5β,10β,15β-tris(2,5-dimethoxyphenyl)-10,15-dihydro-
5H-diindeno[1,2-a;1Ј,2Ј-c]fluorene (15d): nBuLi (11.25 mL,
28.13 mmol, 2.5  in hexane) was added at –78 °C to a solution
of 1-bromo-2,5-dimethoxybenzene (4.22 mL, 28.13 mmol) in Et2O
(20 mL). The mixture was warmed up to 15 °C and a suspension
(br.s, 9 H), 6.17 (br.s, 3 H), 6.63 (br.s, 6 H), 7.03–7.16 (m, 12 H),
7.39–7.48 (m, 6 H) ppm. 13C NMR (CDCl3, 75 MHz): δ = 48.55,
55.72, 110.77, 121.31, 122.79, 124.46, 126.56, 126.61, 127.67,
129.85, 138.83, 139.86, 157.15 (some signals were not observed, due
to overlapping) ppm. EI-MS: m/z (%) = 660 (100) [M]+, 552 (22),
445 (18). HRMS: m/z for C48H36O: calcd. 660.2664; found
660.2667.
4136
© 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
Eur. J. Org. Chem. 2005, 4127–4140

New Building Blocks Based on Truxene Cores
FULL PAPER
Isomerization of anti-16a to syn-17a: A suspension of 16a (71 mg,
0.11 mmol) and KOtBu (15 mg) was heated under reflux in tBuOH
(10 mL) for 17 h. After having been cooled to room temperature,
the mixture was partitioned between water and CH2Cl2. Extractive
workup and chromatography (hexane/CH2Cl2, 2:1) gave 17a
(49 mg, 69%).
H) ppm. EI-MS: m/z (%) = 660 (100) [M]+, 568 (14), 552 (41), 445
(21), 401 (7). HRMS: m/z for C48H36O3: calcd. 660.2664; found
660.2657.
Isomerization of anti-16c to syn-17c: A suspension of 16c (250 mg,
0.35 mmol) and KOtBu (20 mg) was heated under reflux in tBuOH
(10 mL) for 48 h. After having been cooled to room temperature,
the mixture was partitioned between water and CH2Cl2. Extractive
workup and trituration with hexane/CH2Cl2 gave 17c (150 mg,
65%).
5α,10α,15β-Tris(3-methoxyphenyl)-10,15-dihydro-5H-diindeno[1,2-
a;1Ј,2Ј-c]fluorene (16b) and 5α,10α,15α-Tris(3-methoxyphenyl)-
10,15-dihydro-5H-diindeno[1,2-a;1Ј,2Ј-c]fluorene (17b): The pro-
cedure described for the synthesis of 16a and 17a was applied to
14b/15b (450 mg, 0.64 mmol), Et3SiH (2.48 mL, 15.61 mmol), and
BF3·OEt2 (1.24 mL, 8.95 mmol). A ca. 10:1 mixture of 16b and 17b
(370 mg, 88%) was obtained as a yellow solid. The mixture was
separated by column chromatography (hexane/EtOAc, 5:1). 16b:
White solid; m.p. 238–240 °C; Rf = 0.41 (3:1 hexane/EtOAc). 1H
NMR (CDCl3, 300 MHz): δ = 3.62 (s, 3 H), 3.65 (s, 3 H), 3.66 (s,
3 H), 5.60 (s, 2 H), 5.62 (s, 1 H), 6.67–6.71 (m, 6 H), 6.85–6.88 (m,
1 H), 6.95–7.01 (m, 2 H), 7.10–7.22 (m, 9 H), 7.42–7.46 (m, 3 H),
7.52–7.61 (m, 3 H) ppm. 13C NMR (CDCl3, 75 MHz): δ = 53.93,
54.05, 54.93, 55.08, 11.64, 11.81, 112.14, 112.64, 112.89, 113.40,
120.03, 120.20, 123.46, 123.60, 124.44, 124.61, 124.66, 126.89,
126.95, 129.96, 138.72, 138.80, 139.11, 139.19, 139.25, 139.34,
139.50, 142.90, 142.97, 148.60, 148.73, 160.03 (some signals were
not observed, due to overlapping) ppm. EI-MS: m/z (%) = 660
(100) [M]+, 552 (37), 445 (42), 401 (9). HRMS: m/z for C48H36O3:
calcd. 660.2664; found 660.2658. 17b: White solid; m.p. Ͼ300 °C;
5α,10α,15β-Tris(2,5-dimethoxyphenyl)-10,15-dihydro-5H-di-
indeno[1,2-a;1Ј,2Ј-c]fluorene (16d) and 5α,10α,15α-Tris(2,5-dimeth-
oxyphenyl)-10,15-dihydro-5H-diindeno[1,2-a;1Ј,2Ј-c]fluorene (17d):
The procedure described for the synthesis of 16a and 17a was ap-
plied to 14d/15d (1.80 g, 2.25 mmol), Et3 SiH (6.00 mL,
37.77 mmol), and BF3·OEt2 (3.00 mL, 23.84 mmol). A ca. 3:1 mix-
ture of 16d and 17d (1.25 g, 74%) was obtained as a yellow solid.
The mixture was separated by column chromatography (hexane/
CH2Cl2, 1:2). 16d: White solid; m.p. 278–280 °C; Rf = 0.56 (hexane/
1
CH2Cl2, 1:4). H NMR (CDCl3, 300 MHz): δ = 3.34 (s, 6 H), 3.38
(s, 3 H), 4.17 (s, 9 H), 5.94 (br.s, 1 H), 6.00 (br.s, 1 H), 6.08 (br.s,
1 H), 6.23–6.27 (m, 3 H), 6.59–6.65 (m, 3 H), 6.97–7.00 (m, 3 H),
7.10–7.15 (m, 6 H), 7.42–7.52 (m, 6 H) ppm. 13C NMR (CDCl3,
75 MHz): δ = 46.49, 54.97, 55.08, 55.19, 56.25, 11.33, 111.42,
111.53, 111.69, 112.28, 122.74, 122.88, 124.38, 124.55, 126.56,
126.64, 130.88, 130.97, 138.89, 139.00, 139.11, 139.67, 139.78,
149.54, 149.68, 149.76, 151.38, 151.49, 153.61, 153.68 (some signals
were not observed, due to overlapping) ppm. EI-MS: m/z (%) =
750 (100) [M]+, 735 (4), 719 (7), 612 (20), 475 (9). HRMS: m/z for
C51H42O6: calcd. 750.2981; found 750.2988. 17d: Pale yellow solid;
m.p. 292–294 °C; Rf = 0.46 (hexane/CH2Cl2, 1:4). 1H NMR
(CDCl3, 300 MHz): δ = 3.33 (s, 9 H), 4.15 (s, 9 H), 6.01 (br.s, 3
H), 6.06 (br.s, 3 H), 6.57 (dd, J = 8.9, 3.0 Hz, 3 H), 6.94 (d, J =
8.9 Hz, 3 H), 7.01–7.14 (m, 6 H), 7.40–7.42 (m, 3 H), 7.43–7.48 (m,
3 H) ppm. 13C NMR (CDCl3, 75 MHz): δ = 46.21, 54.88, 56.19,
111.55, 111.86, 112.22, 122.85, 124.41, 126.59, 126.67, 130.88,
138.69, 139.05, 139.86, 149.68, 151.44, 153.66 ppm. EI-MS: m/z
(%) = 750 (100) [M]+, 735 (3), 719 (6), 612 (18), 475 (8). HRMS:
m/z for C51H42O6: calcd. 750.2981; found 750.2980.
1
Rf = 0.23 (hexane/EtOAc, 3:1). H NMR (CDCl3, 300 MHz): δ =
3.58 (s, 9 H), 4.57 (s, 3 H), 6.42 (s, 3 H), 6.60 (dd, J = 8.1, 2.4 Hz,
3 H), 6.66 (d, J = 7.3 Hz, 3 H), 7.08 (t, J = 7.9 Hz, 3 H), 7.22–7.33
(m, 12 H) ppm. 13C NMR (CDCl3, 75 MHz): δ = 53.07, 54.72,
111.78, 112.42, 119.70, 123.74, 124.69, 126.59, 126.73, 129.77,
138.33, 138.80, 139.03, 142.85, 148.79, 159.72 ppm. EI-MS: m/z
(%) = 660 (100) [M]+, 552 (27), 445 (32), 401 (3). HRMS: m/z for
C48H36O3: calcd. 660.2664; found 660.2669.
Isomerization of anti-16b to syn-17b: A suspension of 16b (250 mg,
0.35 mmol) and KOtBu (20 mg) was heated under reflux in tBuOH
(10 mL) for 17 h. After having been cooled to room temperature,
the mixture was partitioned between water and CH2Cl2. Extractive
workup and trituration with hexane/CH2Cl2 gave 17b (160 mg,
70%).
5α,10α,15α-Tris(2-hydroxyphenyl)-10,15-dihydro-5H-diindeno[1,2-
a;1Ј,2Ј-c]fluorene (18a): BBr3 (0.78 mL, 0.78 mmol, 1  in CH2Cl2)
was added at –78 °C to a solution of 17a (85 mg, 0.13 mmol) in
CH2Cl2 (10 mL). The mixture was stirred at –78 °C for 1 h and at
room temperature for 12 h. After being partitioned between
CH2Cl2 and water, and extractive workup, the residue was tritu-
rated with hexane/CH2Cl2, and then with EtOAc to give 18a
5α,10α,15β-Tris(4-methoxyphenyl)-10,15-dihydro-5H-diindeno[1,2-
a;1Ј,2Ј-c]fluorene (16c) and 5α,10α,15α-Tris(4-methoxyphenyl)-
10,15-dihydro-5H-diindeno[1,2-a;1Ј,2Ј-c]fluorene (17c): The pro-
cedure described for the synthesis of 16a and 17a was applied to
14c/15c (450 mg, 0.64 mmol), Et3SiH (2.48 mL, 15.61 mmol), and
BF3·OEt2 (1.24 mL, 8.95 mmol). A ca. 10:1 mixture of 16c and 17c
(305 mg, 72%) was obtained as a yellow solid. The mixture was
separated by column chromatography (hexane/CH2Cl2, 4:1). 16c:
White solid; m.p Ͼ300 °C; Rf = 0.5 (hexane/CH2Cl2, 2:1). 1H
NMR (CDCl3, 300 MHz): δ = 3.70 (s, 3 H), 3.71 (s, 3 H), 3.72 (s,
3 H), 5.57 (s, 1 H), 5.58 (s, 1 H), 5.60 (s, 1 H), 6.74–6.82 (m, 6 H),
7.08–7.22 (m, 12 H), 7.37–7.42 (m, 3 H), 7.51–7.56 (m, 3 H) ppm.
13C NMR (CDCl3, 300 MHz): δ = 53.21, 53.27, 55.05, 114.34,
114.40, 114.45, 123.54, 123.71, 124.33, 124.58, 126.67, 126.75,
128.26, 133.19, 133.30, 138.55, 138.60, 139.08, 139.10, 139.16,
1
(58 mg, 72%): White solid; m.p. Ͼ300 °C. H NMR ([D4]MeOH,
300 MHz): δ = 6.11 (br.s, 3 H), 6.49 (m, 6 H), 6.95–6.97 (m, 6 H),
7.04–7.10 (m, 6 H), 7.54–7.56 (m, 6 H) (3 H corresponding to the
OH signals were not observed) ppm. 13C NMR ([D4]MeOH,
75 MHz): δ = 47.81, 116.41, 120.96, 124.08, 125.67, 127.51, 128.54,
129.43, 140.09, 140.31, 141.26, 151.44, 156.46 (some signals were
not observed, due to overlapping) ppm. IR: ν = 3560, 3470, 3414,
˜
1621, 1592, 1450, 1148, 1082, 743, 614 cm–1. EI-MS: m/z (%) = 618
(100) [M]+, 524 (40), 431 (23). HRMS: m/z for C45H30O3: calcd.
618.2194; found 618.2185.
139.47, 139.64, 149.17, 149.26, 158.29 (some signals were not ob- 5α,10α,15α-Tris(3-hydroxyphenyl)-10,15-dihydro-5H-diindeno[1,2-
served, due to overlapping) ppm. EI-MS: m/z (%) = 660 (100)
[M]+, 552 (48), 445 (25), 401 (8). HRMS: m/z for C48H36O3: calcd.
660.2664; found 660.2657. 17c: White solid; m.p. Ͼ300 °C; Rf =
a;1Ј,2Ј-c]fluorene (18b): The same procedure as described for the
preparation of 18a was applied to 17b (160 mg, 0.24 mmol) in
CH2Cl2 (10 mL) to give 18b (92 mg, 62 %); white solid; m.p.
Ͼ300 °C. 1H NMR ([D4]MeOH, 300 MHz): δ = 3.89 (s, 3 H), 6.19
1
0.3 (hexane/CH2Cl2, 2:1). H NMR (1,1,2,2-tetrachloro[D2]ethane,
300 MHz): δ = 3.63 (s, 9 H), 4.99 (s, 3 H), 6.71 (d, J = 8.5 Hz, 6 (s, 3 H), 6.29 (dd, J = 8.1, J = 7.1 Hz, 3 H), 6.42 (dd, J = 8.1, J =
H), 7.01 (d, J = 8.4 Hz, 6 H), 7.12–7.19 (m, 6 H), 7.27–7.33 (m, 6 2.4 Hz, 3 H), 6.88 (t, J = 7.7 Hz, 3 H), 7.05 (d, J = 7.7 Hz, 3 H),
Eur. J. Org. Chem. 2005, 4127–4140
www.eurjoc.org
© 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
4137

A. M. Echavarren et al.
FULL PAPER
7.18 (t, J = 7.3 Hz, 6 H), 7.32 (t, J = 7.7 Hz, 3 H) ppm. FAB-MS:
m/z (%) = 618 [M]+ (4), 525 [M]+ (3). HRMS: m/z for C45H30O3:
calcd, 618.2195; found 618.2206.
125.23, 125.40, 128.11, 128.23, 129.92 (br), 130.30 (br), 136.35,
136.42, 136.42, 136.46, 136.54, 136.71, 136.75, 137.49, 137.95,
137.99, 138.16, 139.49, 139.51, 145.69, 146.26, 146.35, 147.48,
147.81, 147.96, 187.07, 187.64, 187.69 (some signals were not ob-
5α,10α,15β-Tris(4-hydroxyphenyl)-10,15-dihydro-5H-diindeno[1,2-
a;1Ј,2Ј-c]fluorene (18c) and 5α,10α,15α-Tris(4-hydroxyphenyl)-
10,15-dihydro-5H-diindeno[1,2-a;1Ј,2Ј-c]fluorene (19c): The same
procedure as described for the preparation of 18a was applied to a
mixture of 16c and 17c (1.00 g, 1.51 mmol) in CH2Cl2 (45 mL) to
give 18c and 19c (652 mg, 70%) as a gray solid. The mixture was
separated by column chromatography (hexane/CH2Cl2, 2:1). 18c:
White solid; m.p. Ͼ300 °C; Rf = 0.48 (hexane/EtOAc, 1:1). 1H
NMR ([D4]MeOH, 200 MHz): δ = 5.51 (s, 1 H), 5.52 (s, 1 H), 5.58
(s, 1 H), 6.61–6.68 (m, 6 H), 6.98–7.01 (m, 12 H), 7.32–7.34 (m, 3
served, due to overlapping) ppm. IR: ν = 2932, 2855, 1650, 1591,
˜
1462, 1292, 916, 736, 420 cm–1. UV/Vis (EtOH): λmax (log ε) = 238
(4.71), 278 (4.57), 299 (4.49) nm. EI-MS: m/z (%) = 660 (100)
[M]+, 207 (50), 165 (47). HRMS: m/z for C45H24O6: calcd,
660.1573; found 660.1575.
2α,5α,15α-Tris[(2,5-cyclohexadien-1,4-dione-2-yl)]-10,15-dihydro-
5H-diindeno[1,2-a;1Ј,2Ј-c]fluorene (21): Phenyliodonium bis(trifluo-
roacetate) (PIFA, 200 mg, 0.46 mmol) was added to a solution of
19d (20 mg, 0.03 mmol) in CH2Cl2 (2 mL) and MeOH (0.2 mL).
H), 7.50–7.59 (m, 3 H) ppm. IR: ν = 3513, 3384 (br), 1694, 1616, The mixture was stirred at room temperature for 40 min. After par-
˜
1592, 1514, 1240, 1172, 745 cm–1. FAB-MS: m/z (%) = 618 [M]+
(15), 525 (8), 460 (6), 382 (17). HRMS: m/z for C45H30O3: calcd.
618.2195; found 618.2190. 19c: White solid; m.p. Ͼ300 °C; Rf =
0.18 (hexane/EtOAc, 1:1). 1H NMR ([D4]MeOH, 300 MHz): δ =
titioning between CH2Cl2 and water and extractive workup, 21
(6 mg, 30%) was obtained; orange solid; m.p. Ͼ300 °C. H NMR
1
(CDCl3, 300 MHz): δ = 5.62 (s, 3 H), 6.13 (s, 3 H), 6.69 (dd, J =
10.1, 2.4 Hz, 3 H), 6.96 (d, J = 10.1 Hz, 3 H), 7.24–7.39 (m, 12
3.78 (s, 3 H), 6.42–6.51 (m, 12 H), 6.93 (d, J = 7.7 Hz, 3 H), 7.07– H) ppm. 13C NMR (CDCl3, 75 MHz): δ = 46.01, 122.60, 125.28,
7.13 (m, 6 H), 7.26 (t, J = 7.3 Hz, 3 H) ppm. 13C NMR ([D4]
128.05, 128.05, 128.17, 131.41 (br), 136.42, 136.74, 138.19, 139.21,
MeOH, 75 MHz): δ = 53.55, 116.52, 125.42, 125.97, 127.31, 127.42, 145.73, 147.49, 186.90, 187.55 ppm. IR: ν = 2924, 2855, 1650, 1600,
˜
129.24, 133.62, 139.03, 140.11, 140.81, 151.05, 156.93 ppm. FAB-
1292, 916, 745, 412 cm–1. UV/Vis (EtOH): λmax (log ε) = 206 (4.58),
237 (4.58), 279 (4.44), 300 (4,34). EI-MS: m/z (%) = 660 (4) [M]+,
322 (35), 207 (18), 167 (100) nm.
M: m/z (%) = 618 (1) [M]+.
5α,10α,15β-Tris(2,5-dihydroxyphenyl)-10,15-dihydro-5H-diindeno-
[1,2-a;1Ј,2Ј-c]fluorene (18d): The same procedure as described for
the preparation of 18a was applied to 16d (150 mg, 0.20 mmol) in
CH2Cl2 (15 mL) to give 18d (84 mg, 63 %); gray solid; m.p.
Ͼ300 °C. 1H NMR ([D6]acetone, 200 MHz): δ = 5.70 (d, J =
3.1 Hz, 1 H), 5.89 (d, J = 3.1 Hz, 1 H), 5.93 (d, J = 3.1 Hz, 1 H),
6.19–6.23 (m, 3 H), 6.38–6.45 (m, 3 H), 6.91 (d, J = 8.7 Hz, 3 H),
7.04–7.15 (m, 6 H), 7.57–7.64 (m, 3 H), 7.67–7.70 (m, 3 H) ppm.
13C NMR ([D6]acetone, 75 MHz): δ = 47.40, 113.41, 113.83,
114.83, 114.92, 116.90, 116.95, 123.84, 125.52, 125.63, 127.44,
127.50, 127.61, 129.20, 129.36, 129.64, 139.74, 139.82, 139.93,
140.74, 140.91, 148.64, 148.77, 151.00, 151.06, 151.15, 151.20 (some
Table 4. Collecting parameters, crystal and determination data for
5e.
Diffractometer
Radiation
T [K]
Bruker–Siemens Smart CCD
Cu-Kα (λ = 1.54178 Å)
296(2)
θ [°]
2.37–63.68
inappreciable
–42 Յ h Յ 43, –15 Յ k Յ
14, –21 Յ l Յ 23
C75H48N6
Crystal degradation
Index ranges
Empirical formula
signals were not observed, due to overlapping) ppm. IR: ν = 3504,
Formula mass
Crystal system
Symmetry group
a [Å]
b [Å]
c [Å]
1033.19
monoclinic
C2/c
37.3451(7)
14.3265(3)
22.1848(4)
90.8820(10)
11868.0(4)
8
˜
3308 (br), 1608, 1506, 1454, 1190, 754 cm–1. FAB-MS: m/z (%) =
666 (100) [M]+, 575 (57), 447 (18). HRMS: m/z for C45H30O6: calcd.
666.2042; found 666.2041.
5α,10α,15α-Tris(2,5-dihydroxyphenyl)-10,15-dihydro-5H-diindeno-
[1,2-a;1Ј,2Ј-c]fluorene (19d): The same procedure as described for
the preparation of 18a was applied to 17d (150 mg, 0.20 mmol) in
CH2Cl2 (15 mL) to give 19d (87 mg, 65 %); gray solid; m.p.
β [°]
Volume [Å3]
Z
Calculated density [Mg/m3]
1.156
4320
0.527
1
Ͼ300 °C. H NMR ([D4]MeOH, 300 MHz): δ = 6.04 (br.s, 6 H),
F(000)
6.48 (dd, J = 8.7, 3.0 Hz, 3 H), 6.88 (d, J = 8.5 Hz, 3 H), 7.07–7.15
(m, 6 H), 7.55–57 (m, 3 H), 7.60–7.63 (m, 3 H) ppm. 13C NMR
([D4]MeOH, 75 MHz): δ = 47.83, 114.43, 115.24, 117.11, 124.22,
125.75, 127.59, 130.49, 140.20, 140.31, 141.09, 149.62, 150.93,
µ [mm–1]
Number of reflections observed 9091
Number of independent reflec-
tions
Goodness-of-fit
max/min. ∆ρ [e Å–3]
R factors
5308
151.38 ppm. IR: ν = 3350 (br), 1694, 1600, 1506, 1446, 1352, 1198,
˜
1.002
1.551/–0.323
R1 = 0.1261, wR2 = 0.2883
R1 = 0.0876, wR2 = 0.2452
814, 736 cm–1. FAB-MS: m/z (%) = 666 [M]+ (64), 575 [M –
C6H5O2]+ (35), 490 (9). HRMS: m/z for C45H30O6: calcd. 666.2042;
found 666.2038.
Final R [I Ͼ 2σ(I)]
2α,5α,15β-Tris[(2,5-cyclohexadien-1,4-dione-2-yl)]-10,15-dihydro-
5H-diindeno[1,2-a;1Ј,2Ј-c]fluorene (20): Phenyliodonium bis(trifluo-
roacetate) (PIFA, 242 mg, 0.56 mmol) was added to a solution of
18d (25 mg, 0.04 mmol) in CH2Cl2 (2 mL) and MeOH (0.2 mL).
The mixture was stirred at room temperature for 40 min. After par-
tition between CH2Cl2 and water and extractive workup, 20 (13 mg,
53%) was obtained; orange solid; m.p. Ͼ300 °C. 1H NMR (CDCl3,
300 MHz): δ = 5.85 (br.s, 1 H), 5.90–6.03 (m, 5 H), 6.64–6.73 (m,
X-ray Crystal Structure Determination of 5e: Blue crystals of 5e
suitable for X-ray diffraction studies were obtained by slow concen-
tration of a DMF/Et2O (1:100) solution at 23 °C. Crystals were
mounted on
a Bruker–Siemens Smart CCD diffractometer
equipped with a low-temperature device, a normal-focus, 2.4-kW
sealed-tube X-ray source (Cu-Kα; λ = 1.54178 Å). The cell parame-
3 H), 7.00 (dd, J = 10.1, 2.4 Hz, 3 H), 7.25–7.45 (m, 12 H) ppm. ters were determined by least-squares fit for all reflections col-
13C NMR (CDCl3, 75 MHz): δ = 45.58 (br) 122.60, 122.68, 125.14, lected. Full-matrix least-squares refinements were carried out, min-
4138
© 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
Eur. J. Org. Chem. 2005, 4127–4140

New Building Blocks Based on Truxene Cores
FULL PAPER
2 2
imizing ω(Fo2 – Fc ) . Rw and goodness-of-fit are based on F2. Most
of the calculations were carried out with the SMART software for
data collection and reduction and SHELXTL97[25] for structure
solution and refinement. The collecting parameters, crystal and de-
termination data are given in Table 4.
[1]
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84.
X-ray Crystal Structure Determination of 5f: Blue crystals of 5f suit-
able for X-ray diffraction studies were obtained by slow concentra-
tion of a DMF/Et2O (1:100) solution at 23 °C. Crystals were
mounted on
a Bruker–Siemens Smart CCD diffractometer
equipped with a low-temperature device, a normal-focus, 2.4-kW
sealed-tube X-ray source (Cu-Kα; λ = 1.54178 Å). The cell parame-
ters were determined by least-squares fit for all reflections col-
lected. Full-matrix least-squares refinements were carried out, min-
[4]
imizing ω(Fo – Fc ) . Rw and goodness-of-fit are based on F2.
Most of the calculations were carried out with the SMART soft-
ware for data collection and reduction and SHELXTL97[25] for
structure solutions and refinement. The collecting parameters, crys-
tal and determination data are shown in Table 5.
2
2 2
[5]
[6]
[7]
Table 5. Collecting parameters, crystal and determination data for
5f.
Diffractometer
Radiation
T [K]
Bruker–Siemens Smart CCD
Cu-Kα (λ = 1.54178 Å)
273(2)
[8]
[9]
K. Jacob, J. Y. Becker, A. Ellern, V. Khodorkovsky, Tetrahedron
Lett. 1999, 40, 8625–8628.
θ (°)
2.54–70.54
inappreciable
–21 Յ h Յ 21, 0 Յ k Յ 25, 0 Յ
a) J. Pei, J.-L. Wang, X.-Y. Cao, X.-H. Zhou, W.-B. Zhang, J.
Am. Chem. Soc. 2003, 125, 9944–9945; b) X.-Y. Cao, W.-B.
Zhang, J.-L. Wang, X.-H. Zhou, H. Lu, J. Pei, J. Am. Chem.
Soc. 2003, 125, 12430–12431; c) X.-Y. Cao, X.-H. Liu, X.-H.
Zhou, Y. Zhang, Y. Jiang, Y. Cao, Y.-X. Cui, J. Pei, J. Org.
Chem. 2004, 69, 6050–6058; d) X.-Y. Cao, W. Zhang, H. Zi, J.
Pei, Org. Lett. 2004, 6, 4845–4848; e) W. Zhang, X.-Y. Cao, H.
Zi, J. Pei, Org. Lett. 2005, 7, ol047625c.
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Commun. 1999, 2431–2432; b) B. Gómez-Lor, C. Koper, R. H.
Fokkens, E. J. Vlietstra, T. J. Cleij, L. W. Jenneskens, N. M. M.
Nibbering, A. M. Echavarren, Chem. Commun. 2002, 370–371;
c) B. Gómez-Lor, E. González-Cantalapiedra, M. Ruiz, Ó.
de Frutos, D. J. Cárdenas, A. Santos, A. M. Echavarren, Chem.
Eur. J. 2004, 10, 2601–2608.
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a) M. M. Boorum, Y. V. VasilЈev, T. Drewello, L. T. Scott, Sci-
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jere, Science 2002, 295, 1500–1503.
Crystal degradation
Index ranges
l Յ 20
Empirical formula
Formula mass
Crystal system
Symmetry group
C75H48N6
1033.19
monoclinic
P21/c
a [Å]
b [Å]
c [Å]
18.0281(3)
21.2291(4)
17.5830(3)
105.3230(10)
6490.2(2)
4
[10]
β [°]
Volume [Å3]
Z
Calculated density [Mg/m3]
1.207
F(000)
2480
0.574
[11]
[12]
µ [mm–1]
Number of reflections observed 11833
Number of independent reflec- 8066
tions
Goodness-of-fit
max/min. ∆ρ [e Å–3]
R factors
1.032
0.376, 0.286
R1 = 0.0759, wR2 = 0.1759
R1 = 0.0759, wR2 = 0.1897
[13]
a) Ó. de Frutos, B. Gómez-Lor, T. Granier, M. A. Monge, E.
Gutiérrez-Puebla, A. M. Echavarren, Angew. Chem. Int. Ed.
1999, 38, 204–207; b) Ó. de Frutos, T. Granier, B. Gómez-Lor,
J. Jiménez-Barbero, A. Monge, E. Gutiérrez-Puebla, A. M.
Echavarren, Chem. Eur. J. 2002, 8, 2879–2890.
Final R [I Ͼ 2σ(I)]
[14]
[15]
T. Granier, D. J. Cárdenas, A. M. Echavarren, Tetrahedron
Lett. 2000, 41, 6775–6779.
a) B. Gómez-Lor, Ó. de Frutos, P. A. Ceballos, T. Granier,
A. M. Echavarren, Eur. J. Org. Chem. 2001, 2107–2114; b) M.
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Acknowledgments
We are grateful to the MEC (project CTQ2004-02869), the CAM
(projects 07N/0047/2002 and 07N/0085/2002), and the ICIQ Foun-
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Received: April 13, 2005
Published Online: August 16, 2005
4140
© 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
Eur. J. Org. Chem. 2005, 4127–4140