Photochemistry of styrylcalix[4]arenes

Article abstract of DOI:10.1002/ejoc.200600265

The photochemical transformation of the monostyrylcalix[4]-arenes 12a and 12b either leads to inherent chiral calix[4]phenanthrenes 13a and 13b under basic reaction conditions or to unexpected products of an acid-catalyzed ring cleavage of the macrocycle.

Full text of DOI:10.1002/ejoc.200600265

FULL PAPER
DOI: 10.1002/ejoc.200600265
Photochemistry of Styrylcalix[4]arenes
Michael Mastalerz,[a] Wiebke Hüggenberg,[a] and Gerald Dyker*[a]
Keywords: Calixarenes / Chirality / Photochemistry / Cleavage reactions / Wittig reactions
The photochemical transformation of the monostyrylcalix[4]-
arenes 12a and 12b either leads to inherent chiral ca- are presented.
lix[4]phenanthrenes 13a and 13b under basic reaction condi-
mechanism and the optimization of the reaction conditions
tions or to unexpected products of an acid-catalyzed ring
cleavage of the macrocycle. Studies towards the reaction
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2006)
rylcalix[4]arenes by the well-known photochemical oxida-
tive cyclization of stilbenes (Scheme 2).[14] The initial test
for the oxidative photocyclization of tetrastyrylcalixarene 9
resulted in an unexpected fragmentation of the calixarene
macrocycle, prompting us to thoroughly investigate mech-
anistic and preparative implications of this observation:
Herein we describe the synthesis of monostyrylcalixarenes
12a and 12b and their photolysis under various conditions
to elaborate the mechanism of the photo-induced macro-
cycle cleavage.
Introduction
Studying molecular recognition with artificial supramo-
lecular systems is of broad interest for understanding weak
interactions, which are essential for biological processes on
the molecular level.[1] Calix[4]arenes[2] (1) fixed in the cone
conformation are frequently used as scaffold for the design
of host molecules containing a rigid π-electron-rich cavity
for recognizing cationic,[3] neutral[4] or anionic[5] guests.
The introduction of chirality in calixarenes should create
hosts for the enantioselective recognition of chiral guests.[6]
Besides the functionalization with chiral moieties,[7] in-
herent chirality could be generated by desymmetrization,
for instance by introduction of only one substituent in meta
position of the phenolic unit.[8–10] This is e.g. the case for
some calix[4]naphthalenes (for example 2 in Scheme 1),
where the inherent chirality is caused by their helical topol-
Results and Discussion
Synthesis and Characterization
In order to find optimized reaction conditions for the
ogies.[8,10a,11] Host–guest complexes of 2 with fullerene C60 oxidative photocyclization we first tested model compound
or TMACl have already been described.[11d,11f] Other ca- 6, which had been synthesized in just two preparative steps
lixarenes with macrocyclic aromatic subunits of homo- (Scheme 2): the bromoarene 4 was transformed to the alde-
logues higher than benzene or naphthalene are rare.[12]
hyde 5 by lithiation and subsequent treatment with DMF.
Our intention was to synthesize chiral calixphenan- The stilbene 6 was then obtained in 78% yield and an (E/
threnes[13] (e.g. 3 in Scheme 1) from the corresponding sty- Z) ratio of 60:40 by Wittig reaction. The isomers were sepa-
Scheme 1. Scaffolds of the homologue calix[4]arene (1), calix[4]naphthalene (2) and calix[4]phenanthrene (3).
rated by flash chromatography and were fully characterized
by spectroscopic means. The NMR spectroscopic data of
the (E) isomer were in agreement with those described in
[a] Fakultät für Chemie, Ruhr-Universität Bochum,
Universitätsstrasse 150, 44780 Bochum, Germany
E-mail: gerald.dyker@ruhr-uni-bochum.de
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M. Mastalerz, W. Hüggenberg, G. Dyker
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Scheme 2. Synthesis of model compound 7a by photolysis of the (E/Z)-stilbene 6. a) 1 equiv. nBuLi, THF, –78 °C, 40 min; b) DMF, 2 h,
room temp.; then H+/H2O. c) benzylidenetriphenylphosphonium ylide, THF, –78 °C Ǟ room temp. d) 1 equiv. I2, cyclohexane, hν, 4 h.
literature.[15] A mixture of the (E/Z) isomers 6 in cyclohex- conformation proceeded smoothly, presumably catalyzed by
ane with a stoichometric amount of iodine was irradiated traces of hydrogen chloride in the solvent CDCl3.
with a 125-W Hg medium-pressure lamp. After four hours
Calixarene 9 was irradiated under the same conditions
reaction time we succeeded in isolating a 78% yield of the as the model compound: cyclohexane as solvent, iodine as
expected phenanthrene 7a besides traces of the phenol 7b. oxidant (one equiv. per stilbene unit) and four hours reac-
1
Both compounds were identified by diagnostic H NMR tion time. From the complex product mixture we were able
signals. For example, phenanthrene 7a exhibits two 3 H sin- to isolate only one compound by a combination of flash
glets for the methyl groups at δ = 2.51 and 3.03 ppm. Fur- chromatography and multiple crystallizations from dichlo-
ther typical signals are the Phen-5-H at δ = 8.85 ppm and romethane/acetone: the methylenebis(phenanthrene) 10
the Phen-8-H at δ = 7.88 ppm. A peak at m/z = 264 in the (Scheme 3). This unexpected result led to the question, how
EI-mass spectrum confirms the result.
the fragmentation of the macrocycle took place. For the
For testing the photochemical cyclization at the calixar- formation of 10 obviously at least two CC bond-cleavage
ene moiety we introduced phenylethenyl units at the upper reactions had taken place, presumably at the 4-positions of
rim by a fourfold Wittig reaction[16] at the tetraaldehyde the phenanthrene units, which had been built up during the
8.[17] The tetrastilbene 9 was isolated in a 70% yield as a photochemical process. Consequently the monostilbene 12a
mixture of all possible (E/Z) isomers (Scheme 3). Although was chosen as another model compound, in order to mini-
styrylcalix[4]arenes had been synthesized before with a high mize the possibilities for cleavage reactions to just one. The
(E) selectivity by Heck reactions or by Horner–Wadsworth– monostilbene 12a was synthesized again by Wittig reaction
Emmons reactions,[18,19] we applied standard Wittig condi- (Scheme 4). Subsequent photolysis in cyclohexane indeed
tions resulting in excellent yields of mixtures of (E/Z) iso- gave the expected linear tetramer 14a in 7–15% yield, be-
mers: it was not necessary to separate and purify the (E/Z) sides a mixture of the reactant 12a and the calixphenan-
isomers, because the quantum yield of the photo-induced threne 13a, which could not further be separated by column
(E/Z) isomerization generally is much higher than that of chromatography or fractional crystallization.
the subsequent electrocyclic ring closure.[20] Calixarene 9
Also submolar additions of iodine nevertheless led to the
was identified by a [M+H+] peak at m/z = 1001 in the FAB linear compound 14a. As a key step of the mechanism we
mass spectrum and by comparison of integrals of the aro- considered a [1,9]-sigmatropic H-shift (Scheme 5); in order
1
matic region with those of the aliphatic regions in the H to prove this hypothesis we synthesized the deuterated ca-
1
NMR spectrum. The H NMR spectrum was rather com- lixarene 12b. If the expected H-shift is part of the ring-cleav-
plicate because of the mixture of the six possible (E/Z) iso- ing process, the 4-position of the phenanthrene unit of the
mers. However, the spectrum of the same sample became resulting linear tetramer should be deuterated. After irradi-
rather simple within five days, indicating, that isomerization ation in the presence of an equimolar amount of iodine
of all alkene units to the thermodynamically preferred (E) we isolated 50% of the deuterated calixphenanthrene 13b
Scheme 3. Unexpected macrocycle fragmentation by photolysis of (E/Z)-9. a) Benzyltriphenylphosphonium chloride, nBuLi, THF, 14 h
b) 4 equiv. I2, cyclohexane, 16 h UV irradiation.
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Photochemistry of Styrylcalix[4]arenes
FULL PAPER
Scheme 4. Synthesis and photolysis of monostyrylcalixarenes 12a and 12b. a) benzyltriphenylphosphonium chloride, nBuLi, THF, room
temp., 14 h, yield: 86% 12a; b) D7-benzyltriphenylphosphonium chloride, nBuLi, THF, room temp., 24 h, yield: 71% 12b. c) for yields
and conditions see Table 1.
besides 13% of the linear tetramer 14c, with no deuterium esis, but should be regarded as a hint, that hydrogen trans-
in the 4-position of the phenanthrene scaffold (proven by a fer from the solvent cyclohexane to the linear tetramer 14c
1
distinct singlet at δ = 8.00 ppm in the H NMR spectrum). took place. Changing the photolysis conditions for 12a by
This result clearly disproved our initial [1,9]-H-shift hypoth- the use of benzene as solvent, the reaction gave 22% of the
Scheme 5. Excluding a [1,9]-H-shift during photolysis of the deuterated stilbene 12b.
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Table 1. Reaction conditions and yields of the stilbene photolyses of doublets with geminal coupling constants of roughly
after 16 h of irradiation.
14 Hz, four singlets were detected.
1
The H NMR spectrum of the racemic compound 13a
exhibits some remarkable signals with strong relative shifts,
caused by the overall topology including the phenanthrene
unit (Figure 1): The equatorial methylene proton proximate
to the bay-region of the phenanthrene unit (Hd in Figure 1)
suffered a strong diatropic shift and appears at δ =
4.70 ppm. This is explained by the ring current effect of the
topologically fixed phenanthrene moiety. A similar aniso-
tropic effect could be detected for the protons Ha, Hb and
Hc. They were paratropically shifted and gave two doublets
at δ = 5.43 ppm (Ha) and 5.86 ppm (Hc) and a triplet at δ
= 5.94 ppm (Hb).
Entry Reactant
Solvent
Additions
Products (yields)
1
2
3
4
5
9
cyclohexane
cyclohexane
benzene
benzene
cyclohexane
I2
I2
10 (4%)
14a (16%)[a]
13a (22%); 14b (39%)
13a (86%)
12a
12a
12a
12b
I2
I2, K2CO3
I2
13b (50%); 14c (13%)
[a] Irradiation time 4 h, after chromatography we isolated besides
the linear tetramer 14a a fraction containing a mixture of 12a and
1
13a we were not able to separate. From H NMR spectroscopy of
the mixed fraction the yield of 13a was estimated to 15%.
calixphenanthrene 13a and 39% of the benzyl iodide 14b.
This indicates that the hydrogen iodide, which is produced
in the course of the reaction, is crucial for the ring cleavage
step. And indeed, if potassium carbonate was added in or-
der to remove hydrogen iodide during irradiation, the ring
opening was suppressed to only marginal amounts of less
than 1%. Thus, calixphenanthrene 13a was isolated in a
very good yield of 86%.
Mechanistic Rationale
The proposed reaction mechanism for the ring cleavage
is depicted in Scheme 6: (E)- and (Z)-stilbene 12a were in a
photostationary dynamic equilibrium. The (Z)-stilbene 12a
is able to react in a 6π electrocyclic ring closure to the dihy-
drophenanthrene 15. Oxidation with half an equivalent of
iodine leads to the phenanthryl radical 16, which profits
All compounds were identified by NMR spectroscopy. from the rearomatization of one six-membered ring. The
Typical of the linear tetramers 14a–c is the phenanthrene 4- generated hydrogen iodide is a strong Brønstedt acid (pKa
1
H appearing as singlet in the H NMR spectrum at δ = = –10) and therefore able to protonate 16 in the enol ether-
8.00 ppm for compound 14a, at δ = 8.01 ppm for 14c and type α-positon to give the radical cation 17. Subsequently
at δ = 7.87 ppm for 14b, thus being indicative for the ring the iodide anion cleaves the macrocycle by a nucleophilic
cleavage. Another evidence for the ring opening is the loss substitution at the bridging methylene unit in β-position,
of the characteristic pattern of the bridging methylene pro- which results in the formation of 18. Subsequent oxidation
tons typical of fixed cone-conformed calix[4]arenes. Instead again results in the iodated linear tetramer 14b. Addition of
1
Figure 1. H NMR spectrum of compound 13a, recorded at 400 MHz in CDCl3.
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Photochemistry of Styrylcalix[4]arenes
FULL PAPER
potassium carbonate effectively prevents ring cleavage by nism,[21] although to the best of our knowledge the photo-
trapping the generated hydrogen iodide and therefore 16 is chemical reaction between benzyl iodide and cyclohexane
then exclusively converted into the calix[4]phenanthrene has not been described yet.[21c] We tested this final step of
13a. Performing the photolysis in benzene as solvent gave our mechanistic hypothesis by monitoring the photolysis of
the iodated compound 14b as the favoured linear tetramer a cyclohexane/benzyl iodide mixture by GC. After 31 h of
instead of 14a in cyclohexane. This result strongly implies irradiation, the reaction mixture shows the typical purple
that cyclohexane takes part as reactant in the formation of colour of I2. As expected, an increasing concentration of
14a. Therefore, we proposed an exchange of the benzylic toluene was observed, accompanied by a decreasing con-
iodine with a hydrogen of cyclohexane by a radical mecha- centration of benzyl iodide. We also detected an almost
Scheme 6. Mechanistic rationale for the photochemical transformation of stilbene 12a to the linear tetramer 14a.
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M. Mastalerz, W. Hüggenberg, G. Dyker
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69 °C. IR (KBr): ν = 3022 cm–1, 2959, 2931, 2872, 1631, 1598, 1492,
˜
constant amount of cyclohexyl iodide in the reaction mix-
ture. This result supports the suggested mechanism of the
macrocycle cleavage and gives an explanation for the cata-
lytic amount of I2, which is sufficient for the ring-opening
reaction.
1465, 1446, 1402, 1384, 1308, 1279, 1249, 1218, 1179, 1130, 1068,
1036, 1005, 961, 917, 887, 839, 774, 748, 695, 592. UV/Vis (n-hex-
ane): λmax (lgε) = 295 nm (5.1), 231 (5.3), 202 (5.4). 1H NMR
(400.1 MHz, CDCl3): δ = 0.94–1.01 ppm (m, 12 H, OCH2-CH2-
CH3), 1.87–1.91 (m, 8 H, OCH2-CH2-CH3), 2.83 (“t”), 3.04 (“t”),
3.22 (“d”, all together 4 H, all ArCH2Ar) 3.70–3.90 (m, 8 H, Ar-
OCH2-C2H5), 4.27–4.51 (m, 4 H, Ar-CH2-Ar), 6.00–7.55 (m, 36 H,
alkene-H and ArH). 13C NMR (100.6 MHz, CDCl3):
δ =
Conclusions
10.27 ppm, 10.34, 10.45 (all q, O-CH2-CH2-CH3), 23.18, 23.26
(both t, O-CH2-CH2-CH3), 30.97, 31.13 (both t, Ar-CH2-Ar),
76.90, 77.25 (both t, O-CH2-CH2-CH3), 126.22, 126.38, 126.44,
126.60, 126.68, 126.77, 126.90, 127.59, 127.96, 128.14, 128.19,
128.23, 128.29, 128.39, 128.52, 128.61, 128.71, 128.87, 129.25,
129.38, 130.66, 130.75, 130.86, 131.02, 134.08, 134.46, 134.79,
134.86, 135.03, 137.79, 137.84, 137.88, 137.99, 155.97 (s, ArC-O-),
156.30 (s, ArC-O-). MS (FAB): m/z (%) = 1001 (100) [M+H+], 959
(9), 899 (14), 795 (9). C72H72O4·1/2H2O (1010.37): calcd. C 85.59,
H 7.28; found C 85.27, H 7.20.
With optimized reaction conditions for the oxidative
photocyclization of styryl-substituted calixarenes we suc-
ceeded in the synthesis of the first calix[4]phenanthrene 13a
in high yields up to 86%. Strongly basic reaction conditions
are a prerequisite for the formation of this inherent chiral
cavitand; otherwise, cleavage of the macrocycle catalyzed by
the strongly acidic hydrogen iodide is observed. Currently
we are investigating the preparation of calix[4]phenan-
threnes containing two, three and four phenanthrene units
and the enantiomeric enrichment of 13a.
3,5-Dimethyl-4-(propyloxy)benzaldehyde (5): To a cooled (–78 °C)
solution of bromophenol ether 4 (2.190 g, 9.0 mmol) in THF
(30 mL) nBuLi (6.5 mL of a 1.6 molar hexane solution, 10.4 mmol)
was added and the mixture stirred for 40 min at –78 °C. DMF
(5 mL) was added and the mixture stirred 2 hours at room tempera-
ture. The mixture was quenched with hydrochloric acid (100 mL,
1 ), and extracted 3× with dichloromethane (50 mL). The organic
layer was washed once with water (50 mL), once with brine
(100 mL) and dried with magnesium sulfate. Solvents were removed
by rotary evaporation to give 1.764 g of a yellow liquid. Purifica-
tion by flash chromatography (PE/EA, 15:1) gave 1.154 g (67%) of
the aldehyde 5 as colourless liquid. TLC (PE/EA, 6:1): Rf = 0.35.
1H NMR (200.1 MHz, CDCl3): δ = 1.08 ppm (t, J = 7.3 Hz, 3 H,
-OCH2CH2CH3), 1.85 (sext, J = 7.1 Hz, 2 H, -OCH2CH2CH3),
2.34 (s, 6 H, Ar-CH3), 3.78 (t, J = 6.7 Hz, 2 H, O-CH2CH2CH3),
Experimental Section
General Remarks: Melting points (°C, uncorrected values) were de-
termined with a Kofler instrument, model Reichert Thermovar. El-
emental analyses were determined with a Vario EL. Infrared spec-
troscopy was performed with a Bruker Equinox 55, a Perkin–Elmer
983G or a Perkin–Elmer 841 (KBr, ν in cm–1). UV/Vis-spectra were
˜
1
recorded with a Varian Cary 1 (λmax in nm, ε in cm2 mmol–1). H
and 13C and 31P NMR spectra were recorded with a Bruker DPX
200, a Bruker DRX 400 or a Bruker DRX 600. The spectra were
calibrated on the internal solvent peak δ(CHCl3) = 7.26 ppm (1H)
and 77.05 ppm (13C), the 31P NMR spectrum was calibrated with
phosphourous acid (85%) as external standard (δ = 0.00 ppm).
Mass spectroscopy was performed with a Varian MAT CH5 or a
VG Autospec. FAB spectra were recorded in NBA as matrix. High-
resolution mass spectra were recorded with a Bruker Bio TOF II
calibrated with reserpine. For TLC SiO2 plates (Polygram SIL G/
UV 254) from Macherey–Nagel were used. All compounds were
purified by flash chromatography on Kieselgel 60 (Merck, 0.030–
0.60 mm). All commercially available products were used without
further purification. Solvents were dried with common methods.
The calixarenes 8,[17] 11,[22] and the model compound 4[23] were
synthesized according to literature.
1
7.55 (s, 2 H, Ar-H), 9.87 (s, 1 H, CHO). H NMR spectroscopic
data were in agreement with the literature.[18b]
2,6-Dimethyl-4-[(E/Z)-2-phenylethenyl]-1-(propyloxy)benzene
(6):
To a cooled (–78 °C) solution of benzyltriphenylphosphonium
chloride (2.33 g, 5.99 mmol) in THF (50 mL) and nBuLi (3.75 mL
of a 1.6 molar hexane solution, 6.0 mmol) was added, and the re-
sulting orange suspension stirred 45 min at –78 °C. The aldehyde 5
(1.154 g, 6.00 mmol) was added and the mixture stirred at room
temperature. Water (50 mL) was added after 2.5 h and the organic
layer separated. The organic layer was washed 3× with water
(50 mL), once with brine (50 mL) and dried with magnesium sul-
cone-5,11,17,23-Tetrakis(2-phenylethenyl)-25,26,27,28-tetrakis(pro- fate. Solvents were removed by rotary evaporation and the remain-
pyloxy)calix[4]arene (9): To a cooled (–78 °C) suspension of benzyl-
triphenylphosphonium chloride (2.703 g, 6.95 mmol) in THF
(40 mL) nBuLi (7.20 mmol) was added. The reaction mixture was
stirred 45 min at –78 °C and additional 30 min at room tempera-
ture. The orange-coloured solution was cooled again to –78 °C and
a solution of the tetracarbaldehyde 8 (400 mg, 0.57 mmol) in THF
(10 mL) was added. The reaction mixture was stirred overnight at
room temperature. The reaction was quenched with water (50 mL)
and the separated organic layer washed once with water (50 mL)
and once with brine (50 mL) and dried with magnesium sulfate.
Solvents were removed by rotary evaporation to get roughly 2 g of
a colourless solid. TLC (PE/EA, 2:1): Rf = 0.87 (9), 0.00. After
separation by column chromatography the resulting colourless so-
lid was suspended in methanol (8 mL), 30 min sonicated and sepa-
rated by filtration. The resulting residue was washed with methanol
ing brown residue separated by flash chromatography (petroleum
ether). 1st Fraction [Rf(PE/EA, 6:1) = 0.68]: 501 mg (31%) of the
(Z) isomer as colourless oil. IR (KBr): ν = 3061 cm–1, 3014, 3010,
˜
2962, 2927, 2874, 2855, 1599, 1482, 1383, 1301, 1217, 1179, 1132,
1065, 1041, 1005, 967, 890, 772, 694. UV/Vis (n-hexane): λmax (lgε)
= 288 nm (3.2), 228 (4.4). 1H NMR (200.1 MHz, CDCl3): δ =
1.07 ppm (t, J = 7.4 Hz, 3 H, -OCH2CH2CH3), 1.82 (sext, J =
7.1 Hz, 2 H, -OCH2CH2CH3), 2.16 (s, 6 H, Ar-CH3), 3.72 (t, J =
6.7 Hz, 2 H, O-CH2CH2CH3), 6.49 (“d”, „J” = 2.3 Hz, 2 H, alkene-
H), 6.90 (s, 2 H, Ar-H), 7.17–7.28 (m, 5 H, ArЈ-H). 13C NMR
(100.6 MHz, CDCl3): δ = 10.66 ppm (q, -OCH2CH2CH3), 16.23 (t,
OCH2CH2CH3), 23.69 (q, Ar-CH3-), 73.90 (t, OCH2CH2CH3),
126.97 (s, ArC-CH3), 128.12, 128.89, 129.26 (all d, all ArЈC-H),
129.32 (d, ArC-H), 130.05, 130.66 (both d, both alkene-C), 132.52
(s, ArC-CH=CH-ArЈ), 137.55 (s, ArЈ-C-1), 155.29 (s, ArC-O). MS
(2 × 2 mL) and dried in vacuo (1.4 mbar, 50 °C) to get 397 mg (EI = 70 eV): m/z (%) = 267 (12) [M+1]+, 266 (57) [M]+, 225 (17),
(70%) of the tetrastilbene 9 as a colourless solid with m.p. 64– 224 (100), 223 (27), 208 (6), 205 (9), 194 (8), 181 (7), 180 (36), 179
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Photochemistry of Styrylcalix[4]arenes
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(32), 178 (24), 165 (25), 152 (8), 117 (12), 115 (10), 91 (17), 89 (8), OCH2-CH2-CH3), 1.92 (m, J = 7.5 Hz, 4 H, OCH2-CH2-CH3), 4.19
59 (9), 51 (8), 49 (6), 43 (9), 41 (8), 39 (6), 28 (7), 27 (7). C19H22O (t, J = 7.5 Hz, 4 H, Phen-OCH2-C2H5), 4.38 (s, 2 H, Phen-CH2-
(266.38): calcd. C 85.67, H 8.32; found C 85.58, H 8.72. 2nd Frac-
Phen), 7.55–7.61 (m, 8 H, Phen-6/7/9/10-H), 7.64 (s, 2 H, Phen-1-
H), 7.86 (d, J = 7.0 Hz, 2 H, Phen-8-H), 8.01 (s, 2 H, Phen-4-H),
tion [Rf(PE/EA, 6:1) = 0.63]: 752 mg (47%) of the (E) isomer as
1
colourless oil. H NMR (200.1 MHz, CDCl3): δ = 1.10 ppm (t, J 8.60 (d, J = 8.5 Hz, 2 H, Phen-5-H). 13C NMR (100.6 MHz,
= 7.5 Hz, 3 H, -OCH2CH2CH3), 1.85 (sext, J = 7.1 Hz, 2 H,
-OCH2CH2CH3), 2.32 (s, 6 H, Ar-CH3), 3.75 (t, J = 6.6 Hz, 2 H, CH2-CH3), 30.84 (t, Phen-CH2-Phen), 69.76 (t, O-CH2-CH2-CH3),
O-CH2CH2CH3), 7.01 (“s”, 2 H, alkene-H), 7.19 (s, 2 H, Ar-H), 102.58 (d, Phen-C-4), 122.53 (d, Phen-C-5), 124.23 (d, Phen-C-6),
CDCl3): δ = 10.81 ppm (q, O-CH2-CH2-CH3), 22.82 (t, O-CH2-
7.24 (“t”, “J” = 7.3 Hz, 1 H, ArЈ-4-H), 7.35 (“t”, “J” = 7.5 Hz, 2 125.95 (d, Phen-C-9), 126.11 (d, Phen-C-7), 126.46 (s, Phen-C-10a),
H, ArЈ-3/5-H), 7.50 (“d”, “J” = 7.3 Hz, 2 H, ArЈ-2/6-H). 13C NMR
(100.6 MHz, CDCl3): δ = 10.68 ppm (q, -OCH2CH2CH3), 16.42 (t,
126.62 (d, Phen-C-10), 128.63 (d, Phen-C-8), 129. 86 (s, Phen-C-2),
130.11 (s, Phen-C-4b), 130.26 (d, Phen-C-1), 130.51 (s, Phen-C-
O-CH2CH2CH3), 23.70 (q, Ar-CH3-), 74.01 (t, O-CH2CH2CH3), 4a), 132.16 (s, Phen-C-8a), 156.77 (s, PhenC-O-). MS (EI = 70 eV):
126.37, 127.03, 127.31 (all d, all ArЈC-H), 127.49 (s, ArC-CH3),
128.48, 128.67 (both d, both alkene-C), 131.19 (d, ArC-H), 132.72
m/z (%) = 486 (9), 485 (40), 484 (100) [M+], 399 (7), 381 (9), 353
(5), 352 (6), 291 (12), 243 (5), 236 (15), 235 (5), 207 (17), 206 (5),
(s, ArC-CH=CH-ArЈ), 137.72 (s, ArЈ-C-1), 156.00 (s, ArC-O). 194 (19), 178 (11), 165 (5), 69 (5), 59 (14), 58 (7), 57 (8), 56 (7), 44
NMR spectroscopic data were in accord with the literature.[18b]
(5), 43 (20), 42 (9), 31 (5), 29 (7), 28 (9), 27 (5). HRMS (ESI-TOF):
calcd. for C35H32O2Na [M+Na+]: 506.2216; found 506.2158.
2,4-Dimethyl-3-(propyloxy)phenanthrene (7a) and 2,4-Dimethyl-3-
phenanthrenol (7b): A solution of the (E/Z)-stilbene 6 (134 mg,
0.50 mmol) and iodine (132 mg, 1.04 mmol) in cyclohexane
(200 mL) was degassed with argon (30 min) and irradiated for 4 h
(125-W Hg medium-pressure lamp, quartz filter). During the reac-
tion period a permanent argon stream was bubbled through the
solution. Cyclohexane was removed by rotary evaporation and the
remaining residue was separated by flash chromatography (petro-
cone-(E/Z)-5-(2-Phenylethenyl)-25,26,27,28-tetrakis(propyloxy)-
calix[4]arene (12a): To a cooled (–78 °C) solution of benzyltri-
phenylphosphonium chloride (132 mg, 0.33 mmol) in THF (8 mL)
nBuLi (0.25 mL of a 1.6 molar hexane solution, 0.40 mmol) was
added and the resulting orange suspension stirred 30 min at –78 °C.
A solution of calixarene 11 (175 mg, 0.28 mmol) in THF (8 mL)
was added and the reaction mixture stirred at room temperature
leum ether): 1st Fraction (Rf = 0.28): 4 mg (3 %) of the hy- for 14 h. Water (10 mL) and dichloromethane (50 mL) was added
1
droxyphenanthrene 7b as pale yellow solid. H NMR (200.1 MHz,
and the organic layer separated. The organic layer was washed 2×
CDCl3): δ = 2.53 ppm (s, 3 H, Ar-CH3), 3.13 (s, 3 H, Ar-CH3), with water (50 mL), once with brine (50 mL) and dried with mag-
7.34 (br. s, 1 H, -OH), 7.53–7.67 (m, 5 H, Phen-H), 7.90 (m, 1 H, nesium sulfate. Solvents were removed by rotary evaporation to
Phen-8-H), 8.89 (“d”, 1 H, Phen-5-H). 2nd Fraction (Rf = 0.12):
103 mg (78%) of the phenanthrene 7a as pale yellow oil. IR (KBr):
˜
remain 300 mg of a colourless solid. Purification by flash
chromatography (PE/EA, 6:1, Rf = 0.50) and additional drying in
ν = 3083 cm–1, 2963, 2933, 2875, 1602, 1493, 1452, 1379, 1330, vacuo (0.2 mbar, 100 °C) gave 168 mg (86%) of the (E/Z)-calixar-
1261, 1217, 1159, 1143, 1118, 1064, 1043, 1005, 961, 876, 806, 745.
UV/Vis (n-hexane): λmax (lgε) = 352 nm (2.4), 335 (2.5), 300 (3.9), 2959 cm–1, 2929, 2873, 1590, 1453, 1384, 1290, 1248, 1215, 1194,
288 (3.8), 276 (3.9), 254 (4.6), 227 (4.2). 1H NMR (400.1 MHz,
1123, 1087, 1037, 1007, 966, 889, 842, 758, 695. UV/Vis (n-hexane):
CDCl3): δ = 1.16 ppm (t, J = 7.4 Hz, 3 H, -OCH2CH2CH3), 1.95 λmax (lg ε) = 318 nm (3.8), 306 (4.2), 204 (4.1). 1H NMR
(sext, J = 7.1 Hz, 2 H, -OCH2CH2CH3), 2.51 (s, 3 H, Ar-CH3), (400.1 MHz, CDCl3): δ = 0.95–1.05 ppm (m, 24 H, OCH2-CH2-
3.03 (s, 3 H, Ar-CH3), 3.89 (t, J = 6.6 Hz, 2 H, O-CH2CH2CH3), CH3), 1.84–1.98 (m, 16 H, OCH2-CH2-CH3), 3.00 (d, J = 13.0 Hz,
7.53–7.64 (m, 5 H, Phen-H), 7.88 (dd, J = 7.7, 1.9 Hz, 1 H, Phen- 2 H, Ar-CH2-Ar), 3.16 (d, J = 13.1 Hz, 4 H, two superimposed
8-H), 8.85 (d, J = 8.8 Hz, 1 H, Phen-5-H). 13C NMR (100.6 MHz, signals, Ar-CH2-Ar), 3.19 (d, J = 13.5 Hz, 2 H, Ar-CH2-Ar), 3.77
ene 12a as colourless solid; m.p. 56–62 °C. IR (KBr): ν =
˜
CDCl3): δ = 10.79 ppm (q, -OCH2CH2CH3), 16.97, 18.20 (both q,
Ar-CH3), 23.71 (t, OCH2CH2CH3), 74.64 (t, OCH2CH2CH3),
(t, J = 7.3 Hz, 4 H, Ar-OCH2-C2H5), 3.83–3.94 (m, 12 H, Ar-
OCH2-C2H5), 4.37 (d, J = 13.0 Hz, 2 H, Ar-CH2-Ar), 4.46 (d, J =
125.11, 125.53, 126.06, 127.24 (all d), 127.53 (s), 127.59 (d, Phen-C- 13.5 Hz, 2 H, Ar-CH2-Ar), 4.47 (d, J = 13.5 Hz, 2 H, Ar-CH2-Ar),
5), 128.59 (d, two superimposed signals, Phen-C-8), 130.07, 130.12, 4.48 (d, J = 13.0 Hz, 2 H, Ar-CH2-Ar), 6.34 (t, J = 4.5 Hz, 2 H,
130.63, 131.49, 133.38 (all s), 156.34 (s, ArC-O). MS (EI = 70 eV): ArH), 6.42–6.47 (m, 6 H, ArH), 6.57–6.63 (m, 8 H, ArH), 6.72–
m/z (%) = 268 (12) [M+4]+, 264 (57) [M]+, 224 (9), 222 (25), 221
6.75 (m, 4 H, ArH), 6.78–6.81 (m, 6 H, ArH), 7.19–7.25 (m, 6 H,
(7), 194 (8), 179 (8), 178 (16), 177 (51), 136 (10), 135 (100), 91 (25), ArH), 7.34 (t, J = 7.5 Hz, 2 H, ArH), 7.46 (d, J = 7.0 Hz, 2 H,
59 (10), 43 (9), 41 (9). C19H20O (264.37): calcd. C 86.32, H 7.62;
found: C 85.33, H 7.86.
ArH). 13C NMR (100.6 MHz, CDCl3): δ = 10.19 ppm, 10.34,
10.43, 10.52 (all q, O-CH2-CH2-CH3), 23.18, 23.22, 23.29, 23.34
(all t, O-CH2-CH2-CH3), 30.97, 31.04 (two superimposed signals),
31.10 (all t, all Ar-CH2-Ar), 76.79 (t, O-CH2-CH2-CH3), 121.84,
121.93, 121.98, 122.02, 122.29 (all d), 126.22 (d), 126.44 (s), 126.60
(d), 126.70 (s), 126.99 (d), 127.86, 128.01, 128.14, 128.41, 128.45,
128.60, 128.89, 128.94, 129.03, 129.14, 129.27, 130.77, 130.81,
131.08 (s), 134.24, 134.44, 134.75, 135.10, 135.34, 135.65, 135.89,
137.86 (all s), 156.04, 156.53, 156.72, 156.97, 157.12 (all s, all ArC-
O-). MS (FAB): m/z (%) = 694 (100) [M + H+]. C48H54O4·
1/4CH2Cl2 (716.18): calcd. C 80.92, H 7.67; found C 80.90, H 7.56.
3,3Ј-Bis(propyloxy)-2,2Ј-methylenebis(phenanthrene) (10): A solu-
tion of the calixarene 9 (160 mg, 0.16 mmol) and iodine (92 mg,
0.72 mmol) in cyclohexane (250 mL) was irradiated 16 h (125-W
Hg medium-pressure lamp, quartz filter). During the reaction
period a permanent argon stream was bubbled through the solu-
tion. Cyclohexane was removed by rotary evaporation and the re-
maining residue separated by flash chromatography. TLC (PE/EA,
8:1): Rf = 0.59, 0.44 (10), 0.22. The fraction with Rf = 0.44 was
dried by rotary evaporation to get 30 mg of an oily, pale yellow
substance. Twofold recrystallization by diffusion of acetone in a
dichloromethane solution and subsequent drying in vacuo gave
6 mg (4%) of 10 as a pale yellow solid; m.p. 198–204 °C. UV/Vis
(n-hexane): λmax (lgε) = 353 nm (3.3), 336 (3.2), 322 (3.1), 305 (3.9),
283 (sh, 4.3), 276 (4.4), 263 (sh, 4.5), 255 (4.6), 221 (4.4), 193 (4.5).
1H NMR (400.1 MHz, CDCl3): δ = 1.08 ppm (t, J = 7.5 Hz, 6 H,
rac-cone-33,34,35,36-Tetrakis(propyloxy)calix[3]benzene[1]phenan-
threne (13a): A suspension of calixarene 12a (50 mg, 0.067 mmol),
iodine (18 mg, 0.071 mmol) and potassium carbonate (600 mg) in
benzene (200 mL) was degassed with argon (30 min) and irradiated
for 14 h (125-W Hg medium-pressure lamp, quartz filter). Benzene
was removed by rotary evaporation and dichloromethane (10 mL)
Eur. J. Org. Chem. 2006, 3977–3987
© 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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3983

M. Mastalerz, W. Hüggenberg, G. Dyker
FULL PAPER
added to the remaining residue. Unsoluble material was filtered off
and dichloromethane removed in vacuo to give a greenish-black
residue. TLC (PE/EA, 15:1): Rf = 0.62, 0.60 (13a), 0.48 (14a, 14b),
0.00. Separation by flash chromatography (PE/EA, 50:1) gave after
drying in vacuo (50 °C, 0.7 mbar) 40 mg (86%) of the racemic ca-
lixphenanthrene 13a as pale yellow solid; m.p. 88–94 °C. IR (KBr):
H, Phen-1-H), 7.55–7.63 (m, 4 H, Phen-H), 7.85 (d, J = 7.8 Hz, J
= 1.0 Hz, 1 H, Phen-8-H), 8.00 (s, 1 H, Phen-4-H), 8.59 (d, J =
8.0 Hz, 1 H, Phen-5-H). 13C NMR (100.6 MHz, CDCl3): δ =
10.62 ppm, 10.77 (both q, both superimposed signals, O-CH2-CH2-
CH3), 16.47 (q, CH2-ArЈЈЈ-CH3), 22.77, 23.64, 23.66 (all t, all O-
CH2-CH2-CH3), 29.46, 29.56, (all t, all Ar-CH2-Ar), 30.18 (t, Phen-
ν = 3053 cm–1, 2960, 2932, 2873, 1558, 1455, 1383, 1336, 1289, CH2-Ar), 69.76 (t, Phen-O-CH2-CH2-CH3), 74.39, 75.02, 75.05,
˜
1246, 1206, 1105, 1086, 1065, 1036, 1006, 967, 881, 842, 800, 758,
77.26 (all t, all Ar-O-CH2-CH2-CH3), 102.52 (d, Phen-C-4), 122.51
(d, Phen-C-5), 123.71, 123.81, 123.86 (all d, all ArC-H), 124.27 (d,
Phen-C-6), 125.96 (d, Phen-C-9), 126.14, 126.46, 126.62 (all d, all
682, 660. UV/Vis (n-hexane): λmax (lgε) = 359 nm (3.0), 344 (3.1),
1
310 (4.2), 263 (4.9). H NMR (400.1 MHz, CDCl3): δ = 0.91 ppm
(t, J = 7.5 Hz, 3 H, O-CH2CH2CH3), 0.92 (t, J = 7.5 Hz, 3 H, O- PhenC-H), 128.61(s), 128.64 (d, Phen-C-8), 128.83, 128.85, 128.89,
CH2CH2CH3), 1.14 (t, J = 7.5 Hz, 3 H, O-CH2CH2CH3), 1.91 (t, 128.93 (all d, all ArC-H), 129.22 (d), 129.81 (s, Phen-C-2), 130.02,
J = 7.5 Hz, 3 H, O-CH2CH2CH3), 1.86–2.13 (m, 8 H, O- 130.08, 131.01, 131.07 (all s), 132.16 (s, Phen-C-8a), 133.73, 134.09,
CH2CH2CH3), 3.16 (d, J = 13.6 Hz, 1 H, ArCH2Ar), 3.18 (d, J = 134.20, 134.22, 134.24 (all s, all ArC-CH2-Ar), 155.87, 155.98,
13.1 Hz, 1 H, ArCH2Ar), 3.38 (d, J = 13.4 Hz, 1 H, ArCH2Ar), 156.04 (all s, all ArC-O), 156.58 (s, PhenC-O). MS (FAB): m/z (%)
3.71 (t, J = 6.8 Hz, 2 H, O-CH2CH2CH3), 3.78 (m, 2 H, O- = 694.4 (28) [M+]. HRMS (ESI-TOF) calcd. for C48H54O4Na
CH2CH2CH3), 4.06 (m, 2 H, O-CH2CH2CH3), 4.29 (td, 2J =
10.8 Hz, 3J = 5.8 Hz, 1 H, Phen-O-CH2CH2CH3), 4.31 (td, 2J =
10.8 Hz, 3J = 5.7 Hz, 1 H, Phen-O-CH2CH2CH3), 4.48 (d, J =
13.4 Hz, 2 H, ArCH2Ar), 4.61 (d, J = 13.4 Hz, 1 H, ArCH2Ar),
4.70 (d, J = 14.6 Hz, 1 H, ArCH2Ar), 4.89 (d, J = 14.6 Hz, 1 H,
ArCH2Ar), 5.43 (d, J = 7.1 Hz, 1 H, ArЈ-3-H), 5.86 (d, J = 6.5 Hz,
1 H, ArЈ-5-H), 5.94 (t, J = 7.6 Hz, 1 H, ArЈ-4-H), 6.08 (“t”, “J” =
6.5 Hz, 1 H, ArЈЈЈ-4-H), 6.22 (m, 2 H, ArЈЈЈ-3/5-H), 6.93 (t, J =
7.5 Hz, 1 H, ArЈЈ-4-H), 7.11–7.16 (m, 2 H, ArЈЈ-3/5-H), 7.53 (m, 2
H, Phen-6/7-H), 7.63 (d, J = 8.5 Hz, 1 H, Phen-9-H), 7.66 (s, 1 H,
Phen-1-H), 7.71 (d, J = 8.8 Hz, 1 H, Phen-10 H), 7.89 (m, 1 H,
Phen-8-H), 8.64 (m, 1 H, Phen-5-H). 13C NMR (100.6 MHz,
CDCl3): δ = 9.89 ppm, 9.93, 10.91, 11.03 (all q, all OCH2CH2CH3),
23.07, 23.13, 23.62, 23.73 (all t, all OCH2CH2CH3), 29.60, 31.11,
31.14 (all t, all ArCH2Ar), 76.58, 76.64, 76.90, 77.55 (all t, all
OCH2CH2CH3), 121.70, 122.33, 122.40 (all d, all Ar-C-4), 124.86
(d, Phen-C-6), 125.12 (d, Phen-C-9), 125.66 (d, Phen-C-7), 126.78
(d, ArЈ-C-3), 127.02 (d, ArЈ-C-5), 127.19 (d, ArЈЈЈ-C-3), 127.27 (d,
Phen-C-10), 127.59 (d, ArЈЈЈ-C-4), 127.94 (d, Phen-C-5), 128.35 (d,
Phen-C-8), 128.58 (s, Phen-C-10a), 128.88, 129.00 (both d, both
ArЈЈC-H), 130,40 (s, Phen-C-4b), 131.21 (s, Phen-C-4a), 132.39,
133.07, 133.33, 133.38, 133.39, 134.39 (all s, all ArC-CH2-Ar),
136.69 (s, Phen-C-4), 137.42 (s, Phen-C-2), 137.52 (s, ArC-CH2-
Ar), 155.04, 155.18, 158.40 (all s, all ArC-O-), 159.51 (s, Phen-
C-O-). MS (FAB): m/z (%) = 692.4 (100) [M+]. C48H52O4·
1/8CH2Cl2 (703.02): calcd. C 82.16, H 7.49; found C 82.27, H 7.34.
[M+Na+]: 717.3914; found 717.3874.
2-{3Ј-[3ЈЈ-(3ЈЈЈ-Iodomethyl-2ЈЈЈ-(propyloxy)benzyl)-2ЈЈ-(propyloxy)-
benzyl]-2Ј-(propyloxy)benzyl}-3-(propyloxy)phenanthrene (14b): A
solution of calixarene 12a (100 mg, 0.13 mmol) and iodine (18 mg,
0.071 mmol) in benzene (220 mL) was degassed with argon
(30 min) and irradiated for 14 h (125-W Hg medium-pressure lamp,
quartz filter). Benzene was removed by rotary evaporation to give
a greenish-black residue. TLC (PE/EA, 20:1): Rf = 0.56, 0.45 (13a),
0.34 (14b), 0.22, 0.16, 0.00. Separation by flash chromatography
(PE/EA, 50:1) gave after drying in vacuo (50 °C, 0.7 mbar): 1st
Fraction (Rf = 0.45): 22 mg (22%) of calixphenanthrene 13a. Ana-
lytical data are in agreement to those described above. 2nd Fraction
(Rf = 0.34): 45 mg (39%) of the benzyl iodide 14b as pale yellow
wax, becoming a deep brown oil after a few hours. IR (KBr): ν =
˜
3058 cm–1, 3028, 2961, 2931, 2873, 1624, 1589, 1519, 1499, 1455,
1384, 1249, 1217, 1156, 1124, 1103, 1081, 1041, 1003, 992, 891,
1
839, 806, 766, 743, 701, 656. H NMR (400.1 MHz, CDCl3): δ =
1.00 ppm (t, J = 7.5 Hz, 6 H, Ar-OCH2CH2CH3), 1.07 (t, J =
7.1 Hz, 3 H, Ar-OCH2CH2CH3), 1.10 (t, J = 7.3 Hz, 3 H, Ar-
OCH2CH2CH3), 1.76–1.87 (m, 8 H, -OCH2CH2CH3), 3.71 (t, J
= 6.4 Hz, 2 H, Ar-OCH2CH2CH3), 3.76 (t, J = 6.4 Hz, 2 H, Ar-
OCH2CH2CH3), 3.93 (t, J = 6.4 Hz, 2 H, Ar-OCH2CH2CH3), 4.11
(s, 2 H, Ar-CH2-Ar), 4.15 (s, 2 H, Ar-CH2-Ar), 4.19 (t, J = 6.4 Hz,
2 H, Phen-OCH2CH2CH3), 4.25 (s, 2 H, Ar-CH2-Ar), 4.56 (s, 2 H,
Ar-CH2I), 6.85–6.97 (m, 8 H, Ar-H), 7.27 (m, 1 H, Ar-H), 7.53 (s,
1 H, Phen-1-H), 7.53–7.65 (m, 5 H, Phen-H), 7.87 (d, J = 7.6 Hz,
1 H, Phen-8-H), 8.00 (s, 1 H, Phen-4-H), 8.60 (d, J = 8.0 Hz, 1
H, Phen-5-H).13C NMR (100.6 MHz, CDCl3): δ = 0.58 ppm (t,
ArCH2I), 10.55, 10.61 (two superimposed signals), 10.76 (all q, all
-OCH2 CH2 CH3 ), 22.76, 23.62, 23.65, 23.70 (all t, all
-OCH2CH2CH3), 29.43, 29.57, 30.18 (all t, all ArCH2Ar), 69.75,
74.51, 75.05 (two superimposed signals) (all t, all -OCH2CH2CH3),
102.51 (d, Phen-C-4), 122.49 (d, Phen-C-5), 123.82, 123.93 (both
d), 124.41 (d, Phen-C-6), 125.96 (d, Phen-C-9), 126.14 (d, Phen-C-
7), 126.45 (s, Phen-C-10a), 126.59 (d, Phen-C-10), 128.62 (d, Phen-
C-8), 128.83, 128.89, 129.16, 129.35 (all d, all ArC-H), 129.80 (s,
Phen-C-2), 130.01 (d, Phen-C-1), 130.08 (s, Phen-C-4b), 130.97 (s),
131.12 (s), 132.14 (d), 132.71 (s, Phen-C-8a), 133.61, 133.77, 134.09,
134.41, 135.02 (all s, all ArC-CH2-Ar), 155.33, 155.88, 155.97,
156.55 (all s, all ArC-O-). MS (FAB): m/z (%) = 843 (2) [M+Na+],
820 (2) [M+], 699 (8), 692 (14) [M+ – HI], 677 (13), 651 (3), 619 (5).
HRMS (ESI-TOF): calcd. for C48H53IO4Na [M+Na+]: 843.2881;
found 843.2898.
2-{3Ј-[3ЈЈ-(3ЈЈЈ-Methyl-2ЈЈЈ-(propyloxy)benzyl)-2ЈЈ-(propyloxy)benz-
yl]-2Ј-(propyloxy)benzyl}-3-(propyloxy)phenanthrene (14a): A solu-
tion of the calixarene 12a (90 mg, 0.13 mmol) and iodine (31 mg,
0.12 mmol) in cyclohexane (200 mL) was degassed with argon
(30 min) and irradiated for 4 h (125-W Hg medium-pressure lamp,
quartz filter). Cyclohexane was removed by rotary evaporation to
remain a brown residue. TLC (PE/EA, 40:1): Rf = 0.31 (12a, 13a),
0.25 (14a). Separation by flash chromatography (PE/EA, 50:1) gave
after drying in vacuo: 1st Fraction: A mixture of 12a and 13a as
1
pale yellow solid (detected by H NMR spectroscopy), that could
not be separated by further column chromatography. 2nd Fraction:
15 mg (16%) of the linear phenanthrene 14a as colourless oil of
1
high viscosity. H NMR (400.1 MHz, CDCl3): δ = 0.98 ppm, 0.99,
1.03 (all t, J = 7.5 Hz, 3 H, Ar-OCH2CH2CH3), 1.06 (t, J = 7.5 Hz,
3 H, Phen-OCH2CH2CH3), 1.78–1.79 (m, 6 H, Ar-OCH2CH2CH3),
1.89 (sext, J = 6.8 Hz, 2 H, Phen-OCH2CH2CH3), 2.32 (s, 3 H, Ar-
CH3), 3.72 (“t”, “J” = 6.4 Hz, two superimposed signals, 4 H, Ar-
OCH2CH2CH3), 3.77 (t, J = 6.4 Hz, 2 H, Ar-OCH2CH2CH3), 4.11
(s, 2 H, Ar-CH2-Ar), 4.15 (s, 2 H, Ar-CH2-Ar), 4.19 (t, J = 6.4 Hz,
([D7]Benzyl)triphenylphosphonium Chloride: To a solution of tri-
2 H, Phen-OCH2CH2CH3), 4.25 (s, 2 H, Ar-CH2-Ar), 6.87–6.97 phenylphosphane (2.008 g, 7.65 mmol) in [D8]toluene (4 mL) [D7]-
(m, 8 H, Ar-H), 7.04 (dd, J = 2.0 Hz, J = 6.8 Hz, 1 H), 7.53 (s, 1 benzyl chloride (1 mL, 8.98 mmol) was added and heated for 16 h
3984
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© 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2006, 3977–3987

Photochemistry of Styrylcalix[4]arenes
FULL PAPER
at 100 °C. After cooling to room temperature, the colourless pre-
cipitate was collected by filtration, washed 3 times with diethyl
ether (5 mL) and dried in a moderate argon stream. Yield: 1.400 g
(46%) of the deuteriophosphonium salt as colourless solid; m.p.
Ͼ300 °C. 1H NMR (400.1 MHz, CDCl3): δ = 5.45 ppm [d, J =
7.3 Hz, C6D5CH2-P+(C6H5)3], 5.46 [d, J = 7.5 Hz, C6D5CHD-
P+(C6H5)3], 7.57–7.62 [m, -P+(C6H5)3], 7.70–7.75 [m, -P+(C6H5)3].
13C NMR (100.6 MHz, CDCl3): δ = 30.37 ppm [m, C6D5CH2-
P+(C6H5)3, C6D5CHD-P+(C6H5)3 und C6D5CD2-P+(C6H5)3], 118.0
5,6,7,8,9-Pentadeuterio-2-{3Ј-[3ЈЈ-(3ЈЈЈ-methyl-2ЈЈЈ-(propyloxy)benz-
yl)-2ЈЈ-(propyloxy)benzyl]-2Ј-(propyloxy)benzyl}-3-(propyloxy)phen-
anthrene (14c) and rac-cone-9,10,11,12-Tetradeuterio-33,34,35,36-
tetrakis(propyloxy)calix[3]benzene[1]phenanthrene (13b): A solution
of deuteriocalixarene 12b (80 mg, 0.11 mmol) and iodine (a tip of
a spatula) in cyclohexane (200 mL) was degassed with argon
(30 min) and irradiated for 16 h (125-W Hg medium-pressure lamp,
quartz filter). Cyclohexane was removed by rotary evaporation to
remain a brown residue. TLC (PE/EA, 40:1): Rf = 0.31 (13b), 0.25
(14c). Separation by flash chromatography (PE/EA, 50:1) gave after
drying in vacuo: 1st Fraction (Rf = 0.31): 38 mg (50%) of deuterated
calixphenanthrene 13b as pale yellow solid. The compound was not
1
3
[dd, JCP = 85.9 Hz, JCD = 3.1 Hz, -P+(ipso-C6H5)3], 127.08 [m,
ipso-C6D5CD2-P+(C6H5)3], 128.05 [m, para-C6D5CD2-P+(C6H5)3],
2
128.54 [m, meta-C6D5CD2-P+(C6H5)3], 130.70 [d, JCP = 13.1 Hz,
-P+(ortho-C6H5)3], 131.14 [m, ortho-C6D5CD2-P+(C6H5)3], 134.40
1
further purified. H NMR (400.1 MHz, CDCl3): δ = 0.93 ppm (t,
3
4
[d, JCP = 10.0 Hz, -P+(meta-C6H5)3], 134.89 [d, JCP = 3.0 Hz,
-P+(para-C6H5)3]. 31P NMR (162.0 MHz, CDCl3): δ = 24.50 ppm
(“t”, “J” s= 11.1 Hz). MS (EI = 70 eV): m/z = 359 (14), 358 (63),
357 (100), 356 (65), 355 (40), 278 (7), 277 (58), 263 (11), 262 (58),
261 (11), 185 (12), 184 (15), 183 (71), 173 (28), 172 (41), 171 (11),
170 (22), 169 (17), 157 (9), 156 (9), 152 (12), 143 (7), 108 (18), 107
(13), 99 (9), 97 (14), 96 (15), 87 (15), 85 (10), 77 (11), 74 (10), 71
(12), 69 (9), 59 (15), 58 (11), 57 (42), 56 (10), 55 (9), 51 (14), 45
(12), 44 (27), 43 (25), 42 (9), 41 (21), 39 (21), 38 (5), 37 (48), 36
J = 7.6 Hz, 3 H, O-CH2CH2CH3), 0.93 (t, J = 7.3 Hz, 3 H, O-
CH2CH2CH3), 1.16 (t, J = 7.4 Hz, 3 H, O-CH2CH2CH3), 1.22 (t,
J = 7.4 Hz, 3 H, O-CH2CH2CH3), 1.86–2.13 (m, 8 H, O-
CH2CH2CH3), 3.16 (d, J = 13.9 Hz, 1 H, ArCH2Ar), 3.18 (d, J =
13.4 Hz, 1 H, ArCH2Ar), 3.40 (d, J = 13.4 Hz, 1 H, ArCH2Ar),
3.73 (t, J = 6.7 Hz, 2 H, O-CH2CH2CH3), 3.80 (m, 2 H, O-
2
CH2CH2CH3), 4.01–4.15 (m, 2 H, O-CH2CH2CH3), 4.23 (td, J =
10.8 Hz, 3J = 5.8 Hz, 1 H, Phen-O-CH2CH2CH3), 4.30 (td, 2J =
10.8 Hz, 3J = 5.7 Hz, 1 H, Phen-O-CH2CH2CH3), 4.50 (d, J =
13.4 Hz, 2 H, ArCH2Ar), 4.63 (d, J = 13.4 Hz, 1 H, ArCH2Ar),
4.72 (d, J = 14.9 Hz, 1 H, ArCH2Ar), 4.91 (d, J = 14.7 Hz, 1 H,
ArCH2Ar), 5.46 (d, J = 7.1 Hz, 1 H, ArЈ-3-H), 5.88 (d, J = 6.8 Hz,
1 H, ArЈ-5-H), 5.96 (t, J = 7.6 Hz, 1 H, ArЈ-4-H), 6.10 (“t”, 1 H,
ArЈЈЈ-4-H), 6.23 (m, 2 H, ArЈЈЈ-3/5-H), 6.95 (m, 1 H, ArЈЈ-4-H),
7.12–7.18 (m, 2 H, ArЈЈ-3/5-H), 7.66 (d, J = 8.6 Hz 1 H, Phen-9-
H), 7.71 (s, 1 H, Phen-1-H), 7.73 (d, J = 8.8 Hz, 1 H, Phen-8-H).
13C NMR (100.6 MHz, CDCl3): δ = 9.90 ppm, 9.94, 10.92, 11.03
(all q, all OCH2CH2CH3), 23.07, 23.13, 23.63, 23.74 (all t, all
OCH2CH2CH3), 26.97, 29.55, 31.15 (all t, all ArCH2Ar), 76.58,
76.64, 76.90, 77.54 (all t, all OCH2CH2CH3), 121.70, 122.33, 122.40
(all d, all Ar-C-4), 125.09 (d, Phen-C-9), 126.79 (d, ArЈ-C-3), 127.04
(d, ArЈ-C-5), 127.19 (d, ArЈЈЈ-C-3), 127.25 (d, Phen-C-10), 127.59
(d, ArЈЈЈ-C-4), 128.35 (d, Phen-C-8), 128.58 (s, Phen-C-10a),
128.88, 129.00 (both d, both ArЈЈC-H), 130.31 (s, Phen-C-4b),
131.17 (s, Phen-C-4a), 132.39, 133.07, 133.33, 133.38, 133.42,
134.38 (all s, all ArC-CH2-Ar), 136.67 (s, Phen-C-4), 137.41 (s,
Phen-C-2), 137.52 (s, ArC-CH2-Ar), 155.04, 155.18, 158.40 (all s,
all ArC-O-), 159.51 (s, PhenC-O-). 2nd Fraction (Rf = 0.25): 10 mg
(13%) of the deuterated phenanthrene 14c as colourless oil of high
1
(18), 35 (8), 29 (822), 28 (21), 27 (8). By comparison the H NMR
spectrum with that of the non-deuterated phosphonium salt the
grade of deuteration in the benzylic position could be estimated to
51%.
cone-(E/Z)-5-[2-(2,3,4,5,6-Pentadeuteriophenyl)-2-deuterioethenyl]-
25,26,27,28-tetrakis(propyloxy)calix[4]arene (12b): To a cooled
(–78 °C) solution of ([D7]benzyl)triphenylphosphonium chloride
(106 mg, 0.27 mmol) in THF (8 mL) nBuLi (0.17 mL of a 1.6 molar
hexane solution, 0.27 mmol) was added, and the resulting orange
suspension stirred at –78 °C for 30 min. A solution of the calixar-
ene 11 (150 mg, 0.24 mmol) in THF (4 mL) was added and the
reaction mixture stirred at room temperature for 24 h. Solvents
were removed by rotary evaporation and the remaining residue
purified by flash chromatography (PE/EA, 100:1, Rf = 0.24). Ad-
ditional drying in vacuo gave 120 mg (71%) of (E/Z)-deuteriocalix-
arene 12b as colourless solid; m.p. 53–55 °C. IR (KBr): ν =
˜
3434 cm–1, 2962, 2932, 2874, 1587, 1558, 1538, 1505, 1456, 1384,
1304, 1289, 1248, 1216, 1195, 1131, 1087, 1067, 1040, 1007, 966,
888, 841, 761. UV/Vis (n-hexane): λmax (lgε) = 308 nm (4.6), 205
(5.1). 1H NMR (400.1 MHz, CDCl3): δ = 0.94–1.04 ppm (m, 24 H,
OCH2-CH2-CH3), 1.84–1.99 (m, 16 H, OCH2-CH2-CH3), 3.00 (d,
J = 13.0 Hz, 2 H, Ar-CH2-Ar), 3.16 (d, J = 13.1 Hz, 4 H, two
superimposed signals, Ar-CH2-Ar), 3.18 (d, J = 13.5 Hz, 2 H, Ar-
CH2-Ar), 3.77 (t, J = 7.3 Hz, 4 H, Ar-OCH2-C2H5), 3.83–3.94 (m,
12 H, Ar-OCH2-C2H5), 4.38 (d, J = 13.0 Hz, 2 H, Ar-CH2-Ar),
4.46 (d, J = 13.5 Hz, 2 H, Ar-CH2-Ar), 4.47 (d, J = 13.5 Hz, 2 H,
Ar-CH2-Ar), 4.48 (d, J = 13.0 Hz, 2 H, Ar-CH2-Ar), 6.34 (t, J =
4.5 Hz, 2 H, ArH), 6.42–6.47 (m, 6 H, ArH), 6.57–6.63 (m, 8 H,
ArH), 6.72–6.75 (m, 4 H, ArH), 6.78–6.81 (m, 6 H, ArH). 13C
NMR (100.6 MHz, CDCl3): δ = 10.19 ppm, 10.22, 10.34, 10.35,
10.42, 10.52 (all q, O-CH2-CH2-CH3), 23.19, 23.22, 23.28, 23.30,
23.33, 23.36 (all t, O-CH2-CH2-CH3), 30.95, 31.06 (two superim-
posed signals), 31.11 (all t, Ar-CH2-Ar), 76.60, 76.64, 76.66, 76.79
(all t, O-CH2-CH2-CH3), 121.84, 121.93, 121.99, 122.02, (all d),
126.41 (s), 126.61, 127.87, 128.03, 128.15, 128.24 128.41, 129.03,
129.18, 129.29, 130.64 (all d), 130.76, 130.85, 131.11, 134.26,
134.46, 134.77, 135.11 135.34, 135.63, 135.88, 137.61, 137.82,
137.88 (all s), 156.06, 156.53, 156.57, 156.73, 156.96, 157.14 (all s,
ArC-O-). MS (FAB): m/z (%) = 700.5 (100) [M+H+]. HRMS (ESI-
TOF): calcd. for C48H48D6O4Na [M + Na+]: 723.4292; found:
723.4291.
1
viscosity. H NMR (400.1 MHz, CDCl3): δ = 0.98 ppm, 0.99, 1.03
(all t, J = 7.5 Hz, 3 H, Ar-OCH2CH2CH3), 1.06 (t, J = 7.5 Hz, 3
H, Phen-OCH2CH2CH3), 1.74–1.83 (m, 6 H, Ar-OCH2CH2CH3),
1.89 (sext, J = 6.8 Hz, 2 H, Phen-OCH2CH2CH3), 2.32 (s, 3 H, Ar-
CH3), 3.72 (“t”, “J” = 6.4 Hz, two superimposed signals, 4 H, Ar-
OCH2CH2CH3), 3.77 (t, J = 6.4 Hz, 2 H, Ar-OCH2CH2CH3), 4.11
(s, 2 H, Ar-CH2-Ar), 4.15 (s, 2 H, Ar-CH2-Ar), 4.19 (t, J = 6.4 Hz,
2 H, Phen-OCH2CH2CH3), 4.25 (s, 2 H, Ar-CH2-Ar), 6.87–6.97
(m, 8 H, Ar-H), 7.04 (dd, J = 1.9 Hz, J = 6.8 Hz, 1 H), 7.53 (s, 1
H, Phen-1-H), 7.58 (s, 1 H, Phen-10-H), 8.00 (s, 1 H, Phen-4-H).
13C NMR (100.6 MHz, CDCl3): δ = 10.60 ppm, 10.61, 10.63, 10.77
(all q, O-CH2-CH2-CH3), 16.47 (q, CH2-ArЈЈЈ-CH3), 22.77, 23.64,
23.66 (all t, all O-CH2-CH2-CH3), 29.46, 29.56, (all t, all Ar-CH2-
Ar), 30.18 (t, Phen-CH2-Ar), 69.76 (t, Phen-O-CH2-CH2-CH3),
74.39, 75.02, 75.05, 77.26 (all t, all Ar-O-CH2-CH2-CH3), 102.53
(d, Phen-C-4), 123.71, 123.81, 123.86 (all d, all ArC-H), 124.22,
126.45, 126.59 (all d, all PhenC-H), 128.60 (s), 128.82, 128.84,
128.89, 128.93 (all d, all ArC-H), 129.22 (d), 129.73, 130.02, 130.07,
131.00, 131.07 (all s), 132.16 (s, Phen-C-8a), 133.73, 134.09, 134.20,
134.22, 134.24 (all s, all ArC-CH2-Ar), 155.87, 155.98, 156.04 (all
s, all ArC-O), 156.57 (s, PhenC-O). MS (FAB): m/z (%) = 699.5
Eur. J. Org. Chem. 2006, 3977–3987
© 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
3985

M. Mastalerz, W. Hüggenberg, G. Dyker
FULL PAPER
(29) [M+]. HRMS (ESI-TOF): calcd. for C48H49D5O4Na
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[M+Na+]: 722.4228; found: 722.4194.
Photolysis of Benzyl Iodide[24] in Cyclohexane: A solution of benzyl
iodide (206 mg, 0.945 mmol) in cyclohexane (200 mL) was de-
gassed with argon for 30 min and irradiated 31 h (125-W Hg me-
dium-pressure lamp, quartz filter). The reaction was monitored by
taking small aliquots of the reaction mixture after 4, 5, 6, 22.75,
24, 26, 28 and 30 h. The samples were analyzed by GC with a
Siemens Sichromat 1–4 with a FID as detector and hydrogen
(0.5 bar) as inert gas with a OV1 methylsilicon column (25 m,
0.2 mm) and the software Chromstar version 3.25 S or by GC/MS
with a Hewlett–Packard 5890 Series II Gas Chromatographer with
a Hewlett–Packard 5972 Series Mass Selective Detector, a ZB-5
w.s.column (30 m, 0.25 mm), thickness 0.25 µm with helium as inert
gas. The formation of I2 was observed by a typical purple colour
of the irradiated reaction mixture, which could be decolourized
with an aqueous thiosulfate solution.
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Acknowledgments
We thank Werner Karow from the University Duisburg-Essen per-
forming the HRMS measurements.
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© 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2006, 3977–3987

Photochemistry of Styrylcalix[4]arenes
FULL PAPER
[23] 4-Bromo-2,6-dimethyl-1-(propyloxy)benzene was prepared as
described in the literature: M. Larsen, F. C. Krebs, N. Harrit,
M. Jørgensen, J. Chem. Soc., Perkin Trans. 2 1999, 1749–1757.
[24] a) Benzyl iodide was synthesized by a method previously de-
scribed: H. Finkelstein, Ber. Dtsch. Chem. Ges. 1910, 43, 1528–
1532; b) The analytical data were in accordance to those de-
scribed by M. Altamura, E. Perrotta, J. Org. Chem. 1993, 58,
272–274.
Received: March 2, 2006
Published Online: June 29, 2006
Eur. J. Org. Chem. 2006, 3977–3987
© 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
3987