Functionalized and Partially or Differentially Bridged Resorcin[4]arene Cavitands: Synthesis and Solid-State Structures

Article abstract of DOI:10.1002/hlca.200390310

We report the synthesis and structural characterization of modified Cram-type, resorcin[4]arene-based cavitands. Two main loci on the cavitand backbone were selected for structural modification: the upper part (wall domain) and the lower part (legs). Synthesis of unsymmetrically bridged cavitands with different wall components (i.e., 7, 8, and 14-18) was performed by stepwise bridging of the four couples of neighboring, H-bonded OH-groups of octol la (Schemes 1, 2, 4, and 5). Cavitands with modified legs (i.e., 20, 24, 27, and 28), targeted for surface immobilization, were synthesized by short routes starting from suitable aldehyde starting materials incorporating either the fully preformed leg moieties or functional precursors to the final legs (Schemes 7-10). The new cavitand substitution patterns described in this paper should enable the construction of a wide variety of functional architectures in the future. X-Ray crystallography afforded the characterization of cavitands 2c (Fig. 3) and 24 (Fig. 7) in the vase conformation, with 2c featuring a well-ordered CH₂Cl₂ guest molecule in its cavity. A particular highlight is the X-ray crystal-structure determination of octanitro derivative 19 (Scheme 6), which, for the first time, shows a cavitand, lacking substituents in the ortho-position to the two O-atoms of the four resorcinol moieties, in the kite-conformation (Fig. 5).

Full text of DOI:10.1002/hlca.200390310

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Helvetica Chimica Acta Vol. 86 (2003)
Functionalized and Partially or Differentially Bridged Resorcin[4]arene
Cavitands: Synthesis and Solid-State Structures
by Vladimir A. Azova), Philip J. Skinnera), Yoko Yamakoshia), Paul Seilera), Volker Gramlichb),
and FranÁois Diederich*a)
a) Laboratorium f¸r Organische Chemie, ETH-Hˆnggerberg, CH-8093Z¸rich
(phone: (0)16322992; fax: (0)16321109; e-mail: diederich@org.chem.ethz.ch)
b) Laboratorium f¸r Kristallographie, ETH-Zentrum, Sonneggstrasse 5, CH-8092 Z¸rich
Dedicated to Professor Duilio Arigoni on the occasion of his 75th birthday
We report the synthesis and structural characterization of modified Cram-type, resorcin[4]arene-based
cavitands. Two main loci on the cavitand backbone were selected for structural modification: the upper part
(wall domain) and the lower part (legs). Synthesis of unsymmetrically bridged cavitands with different wall
components (i.e., 7, 8, and 14 18) was performed by stepwise bridging of the four couples of neighboring, H-
bonded OH-groups of octol 1a (Schemes 1, 2, 4, and 5). Cavitands with modified legs (i.e., 20, 24, 27, and 28),
targeted for surface immobilization, were synthesized by short routes starting from suitable aldehyde starting
materials incorporating either the fully preformed leg moieties or functional precursors to the final legs
(Schemes 7 10). The new cavitand substitution patterns described in this paper should enable the construction
of a wide variety of functional architectures in the future. X-Ray crystallography afforded the characterization
of cavitands 2c (Fig. 3) and 24 (Fig. 7) in the vase conformation, with 2c featuring a well-ordered CH2Cl2 guest
molecule in its cavity. A particular highlight is the X-ray crystal-structure determination of octanitro derivative
19 (Scheme 6), which, for the first time, shows a cavitand, lacking substituents in the ortho-position to the two O-
atoms of the four resorcinol moieties, in the kite-conformation (Fig. 5).
1. Introduction. One of the most fascinating classes of receptors for chemical
molecular-recognition studies comprises the resorcin[4]arene cavitands initially
introduced and studied by Cram and co-workers [1] (Fig. 1). A particularly interesting
property of these systems is the reversible switching between a closed vase
conformation with a deep cavity for guest encapsulation [2] (for supramolecular
Fig. 1. Original resorcin[4]arene cavitand reported by Cram and co-workers [1]

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capsules formed by resorcinarene cavitands, see [3]) and an open kite conformation
with a flat, extended surface. This vase > kite equilibrium is controllable by both
temperature [1] or pH variation [4], and resembles the movement of a molecular
gripper. We became interested in exploring the potential of these switchable
resorcin[4]arenes for single-molecule molecular manipulation (for a first scanning/
tunnelling microscopy (STM) study, imaging the vase conformation at molecular
resolution, see [5]). Integrated into suitable devices such as scanning-probe-
microscopy tips, these cavitands should be able to capture (by complexation) a single
molecule in the vase form and hold it during translocation, while releasing it upon
switching to the nonbonding kite conformation. To reach this objective, much diverse
groundwork is required. Here, we describe the synthesis of switchable resorcin[4]ar-
ene-derived cavitands bearing legs at the lower rim for attachment to solid surfaces [5].
Partial and unsymmetrical bridging of the resorcin[4]arene bowl (for a review on
resorcin[4]arenes, see [6]) greatly expands the range of dynamic cavitands. A series of
derivatives bearing fluorescent −borondipyrromethene×(BODIPY) dyes [7] attached to
the upper rim of the cavitand walls were prepared for mechanistic investigations of the
switching dynamics by polarization-resolved single-molecule microscopy [8] (for a
preliminary report on parts of this work, see [9]). The solid-state structures of cavitands
in both vase and kite conformations are also described. In a following paper [10], we
will report comprehensive investigations defining the experimental conditions under
which the vase > kite equilibrium of fully and partially bridged resorcin[4]arenes can
1
be precisely addressed and studied by H-NMR and optical spectroscopy.
2. Results and Discussion. 2.1. Modification of the Cavity Walls. A variety of
modifications of the cavity walls to tune the size and the inner properties of the
cavitands have been reported by Rebek and co-workers [3][11]. Whereas most of their
work involved the −symmetric×replacement of all four quinoxaline moieties (Fig. 1) by
four new, identical wall components, some −unsymmetric×systems with one flap
differing from the residual three have also been reported [3c,e][12]. For our planned
mechanistic studies of the vaseÀkite switching process by means of single-molecule
confocal fluorescence microscopy in collaboration with B. Hecht (University of Basel),
we were interested in preparing cavitands with one or two diazaphthalimide wall flaps
bearing fluorescent BODIPY dyes. Deep cavitands with the latter array of wall
components had not been previously described.
On the way to the targeted cavitands, three octols 1a 1c with different, solubility-
providing alkyl legs were prepared from resorcinol and the appropriate aliphatic
aldehydes according to a standard protocol [13] (Scheme 1). X-Ray-quality crystals of a
solvate of the isobutyl-legged octol 1c with two MeOH and one EtOH molecules were
obtained by slow cooling of a MeOH/EtOH 4 :1 solution (Fig. 2; for previous X-ray
crystal structures of differently legged octols, see [14]). It was actually possible to grow
large transparent highly solvated rhombic crystals up to several millimeters in size, they
readily lost solvent upon exposure to air and disintegrated. The bowl-shaped
conformation of the octol is stabilized by very short (2.64 2.77 ä) intramolecular
OÀH ¥¥¥ O H-bonds (Fig. 2,a). Each macrocycle forms a network of intermolecular
OÀH ¥¥¥ O H-bonds to a neighboring octol and to the solvent molecules included in the
crystal (Fig. 2,b).

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Scheme 1. Synthesis of Resorcin[4]arenes 2
5
a) Conc. HCl, EtOH, 908, 14 h. b) 2,3-Dichloroquinoxaline (3 equiv.), K2CO3, Me2SO, 208 (8 h), then 508
(18 h); 28% (2a), 35% (3a). c) 2,3-Dichloroquinoxaline (2 equiv.), K2CO3, Me2SO, 208 (18 h), then 508 (6 h);
2.7% (2a), 16.6% (3a), 3.2% (4a), 19.6% (5a).
The partial bridging of octol 1a with 3equiv. of 2,3-dichloroquinoxaline was
subsequently investigated and found to be quite sensitive to the applied experimental
conditions. All reactions in DMF with K2CO3, Cs2CO3, or Et3N as a base were
unsuccessful. They afforded only the fully bridged cavitand 2a together with some tarry
product; additionally, the reaction in the presence of Et3N was very slow. In Me2SO
[2b][15], triply bridged 3a was obtained in 30 35% yield with K2CO3 as base; with
Cs2CO3, only fully bridged 2a was formed. Starting from octols 1b and 1c, lower yields
of the triply bridged derivatives 3b and 3c, respectively, were obtained besides fully
bridged 2b,c; therefore, octol 1a was selected for all future bridging experiments.
Crystals of pentyl-legged 2b as solvate with one CH2Cl2 and two MeCN molecules
were obtained by slow evaporation from MeCN/CH2Cl2. The X-ray crystal structure
shows the cavitand in the vase conformation (Fig. 3,a) with a C2 axis passing through
the cavity (Fig. 3,b). The CH2Cl2 molecule is positioned deeply within the cavity at the
level of the quinoxaline N-atoms. Each Cl-atom is located above the centers of two
adjacent pyrazine rings, with atom-to-ring-center distances of 3.7 3.8 ä. The
disordered MeCN molecules are located one atop the cavity and the second one in
the space between the four pentyl legs. In the crystal lattice, the cavitand molecules
stack in a head-to-tail arrangement, forming infinite, alternating antiparallel columns
(see Fig. 6 below).

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Fig. 2. a) X-Ray crystal structure of the solvated octol 1c with two MeOH and one EtOH molecules (not shown).
Arbitrary numbering. Atomic displacement parameters obtained at 233 K are drawn at the 30% probability
level. Intramolecular O ¥¥¥ O contacts [ä]: O(8) ¥¥¥ O(21), 2.70; O(20) ¥¥¥ O(33), 2.64; O(34) ¥¥¥ O(47) 2.77;
O(7) ¥¥¥ O(46), 2.77. The subunit C(10)ÀC(13) is disordered over two orientations, here only one is shown for
clarity. b) Short intermolecular O¥¥¥ O contacts in the crystal packing of 1c including solvent molecules and
two O-atoms of the neighboring octol. A short CÀH ¥¥¥ O interaction C(302') ¥¥¥ O(34) is also shown. The
position of O(200') is disordered over two orientations.

Fig. 3. a) ORTEP Representation of the cavitand 2b. Arbitrary numbering. Atomic displacement parameters obtained at 295 K are drawn at the 50% probability level.
Intramolecular N ¥¥¥ N distances [ä]: N(15) ¥¥¥ N(46a), 4.42; N(22) ¥¥¥ N(39), 4.24. The subunit C(35)ÀC(36) is disordered over two orientations, here only one is
shown for clarity. The CH2Cl2 molecule located within the cavity and two disordered MeCN molecules outside the cavity are not shown. b) View down the C2 axis into
the cavity filled by the solvent. N ¥¥¥ Cl Distances between the Cl- and N-atoms of adjacent quinoxaline moieties range from 3.64 to 4.02 ä.

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The reaction of octol 1a with 2 equiv. of 2,3-dichloroquinoxaline (Me2SO, K2CO3),
followed by repeated chromatographic purification (SiO2; CH2Cl2/AcOEt mixtures),
afforded anti doubly bridged tetrol 4a in up to 3.2% yield together with the syn-isomer
5a as the major product (up to 20% yield). Cram et al. had previously also observed a
preference for the formation of the syn-isomer during double bridging of an octol with
methylene bridges; in fact, only the syn-product was isolated [16]. The chromato-
graphic purification of the anti-isomer 4a was particularly challenging due to the
presence of a side product with a nearly similar retention time.
Side-products comprised structures with quinoxaline moieties attached to the octol
by one ether linkage only (the structures of these colorless substances with complex
NMR spectra were tentatively assigned by means of mass spectrometry (MS)) as well
as colored material with a low Rf value. The latter presumably consists of products
resulting from ring opening of the octol macrocycle, followed by oxidation under
formation of xanthene dye-type structures [17]. Yields of the desired products increase
and those of side products decrease when i) the starting material is freshly recrystal-
lized and thoroughly dried under high vacuum (10À6 Torr) over P2O5, ii) the mixture is
degassed before initiating the reaction by freeze-pump cycles, and iii) the reaction
temperature is kept below 508.
In a model reaction, the doubly and triply bridged octols 3a and 5a were
transformed with dichlorodiazaphthalimide 6 into the unsymmetrically bridged
cavitands 7 and 8 (Scheme 2). For the preparation of the bridging reagent 6, 2,3-
dichloroquinoxaline was oxidized (KMnO4) to dicarboxylic acid 9 and subsequently
transformed into anhydride 10 [1c]; oxalyl chloride was used instead of previously
reported SOCl2 as the ring-closure reagent. Heating 10 with 4-(tert-butyl)aniline in a
small amount of Ac2O, as reported [1c], did not prove to be very efficient, providing
dichlorodiazaphthalimide 6 in only ca. 20% yield. On the other hand, milder conditions,
with pyridine and oxalyl chloride as activation agents, afforded 6 in 86% yield. The
reaction of 6 with diol 3a and tetrol 5a with K2CO3 in Me2SO provided the fully bridged
cavitands 7 and 8 in 66 and 50% yield, respectively. Neither macrocycle crystallized
well; they eventually precipitated from CHCl3 or THF solutions as very fine slightly
yellowish powders.
For the planned single-molecule fluorescence studies, BODIPY dyes were selected
as luminescent labels for their favorable electronic absorption and emission properties,
and their low sensitivity to pH (which is important in proton-induced switching
experiments) and environmental polarity [7]. Thus, 4-nitrobenzaldehyde was con-
densed with 2,4-dimethyl-3-ethylpyrrole under acidic conditions in CH2Cl2 to form the
corresponding dipyrromethane, which was oxidized with chloranil and subsequently
treated with BF3 ¥ OEt2 in the presence of Et3N to form dye 11 in 38% yield (over the 3
steps; Scheme 3). Reduction of 11 (H2, Pd/C) afforded amine 12, which was coupled
with anhydride 10 to give dichlorodiazaphthalimide 13.
Compound 11 afforded dark-purple crystals upon slow diffusion of hexane into a
CHCl3 solution. The X-ray crystal structure contains three symmetry-independent
molecules in the asymmetric unit with the plane of the BODIPY dye nearly orthogonal
(75 878) to the plane of the attached phenyl ring (Fig. 4). This should also be the case
in the corresponding dye-labeled cavitands 14 16 (Scheme 4). This electronic
decoupling of the p-systems ensures a very small influence of changes in the

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Scheme 2. Synthesis of the Unsymmetrically Bridged Cavitands 7 and 8
a) KMnO4, H2O, 95 978, 2 h; 49%. b) (COCl)2, Py (cat.), THF, 508, 20 min; 61%. c) 4-(tert-butyl)aniline, THF,
1 h, then (COCl)2, Py, 508, 12 h; 89%. d) 3a (1 equiv.), 6 (1 equiv.), K2CO3 (1 equiv.), Me2SO, 208, 24 h; 66%. e)
3a (1 equiv.), 6 (2 equiv.), K2CO3 (2 equiv.), Me2SO, 208, 24 h; 50%. Py ˆ pyridine.
Scheme 3. Synthesis of Dichlorodiazaphthalimide 13
a) TFA, CH2Cl2, 208, 2 h. b) DDQ, toluene, 1 h. c) NEt3, 208 (10 min), then BF3 ¥ OEt2, 208 (30 min), then 508
(1 h); 38% (for steps a c). d) H2 (1 atm), Pd/C (10%), CHCl3/EtOH 1:1, 208, 12 h; 67%. e) 6, THF, 1 h, then
(COCl)2, Py, 508, 12 h; 72%. TFA ˆ CF3COOH, DDQ ˆ 2,3-dichloro-5,6-dicyano-p-benzoquinone.

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Fig. 4. X-Ray crystal structure of BODIPY dye 11. Atomic displacement parameters obtained at 295 K are
drawn at the 30% probability level. Only one of the three nonequivalent conformers in the elementary cell is
shown.
protonation and conformation of the macrocycles on the position of the absorption and
emission bands of the dye.
The BODIPY-substituted cavitands 14 16 were prepared from diol 3a, and tetrols
4a and 5a, respectively, in 54 73% yield (Scheme 4). All three cavitands are brightly
red-colored, featuring sharp optical absorption (530 nm) and emission (540 nm)
maxima in CHCl3 [9].
We also explored the introduction of different bridges into diol 3a and tetrol 5a by
preparing the CH2-bridged cavitands 17 and 18 (CH2BrCl, K2CO3, Me2SO; Scheme 5).
The moderate yields (17: 55%; 18: 48%) can be explained by the steric hindrance
between neighboring quinoxalines, which is enhanced by the short, conformationally
enforcing C1-bridges in the cavitands. Interestingly, cavitand 18 could not be prepared
starting with the corresponding syn-CH2-bridged tetrol [16] and 2,3-dichloroquinoxa-
line.
Finally, octanitrocavitand 19 was synthesized [11a] (Scheme 6) to study its
conformational properties. It is the first resorcin[4]arene cavitand without substituents
in ortho-position to the two O-atoms of the four resorcinol moieties that prefers the
kite-conformation both in solution [10] and in the solid state.
Crystals of 19 were obtained by slow evaporation from acetone solution. They
quickly disintegrated in the air due to the evaporation of solvent enclathrated in the
crystal lattice. Also, they shattered at temperatures below ca. 230 K, probably due to a
phase transition. The X-ray crystal structure obtained at 253K is remarkable. First, the
cavitand is present in the kite-conformation (Fig. 5,a), which had not previously been
observed for this type of resorcin[4]arene-based cavitands. Second, the cavitands do not
form face-to-face dimers, as reported before by Cram et al. [1c,d] for velcraplexes,

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Scheme 4. Synthesis of the Dye-Labeled Cavitands 14 16
a) 3a (1 equiv.), 13 (1 equiv.), K2CO3 (1 equiv.), Me2SO, 208, 24 h; 73 %.b) 4a (1 equiv.), 13 (2.2 equiv.),
K2CO3, (2.2 equiv.), Me2SO, 208, 4 h, then K2CO3, (2.2 equiv.), 30 min; 54%. c) 5a (1 equiv.), 13 (2 equiv.),
K2CO3 (2 equiv.), Me2SO, 208, 24 h; 66%.
dimers of the velcrands, i.e., resorcine[4]arene-based cavitands similar to those
reported here but featuring Me-substituents in ortho-position to the two O-atoms of the
four resorcinol moieties. Rather, the crystal lattice of 19 shows infinite −head-to-
tail×columns with voids filled by Me2CO molecules (Fig. 5,b). We explain the
preference of 19 for the kite-conformation with repulsive local dipoleÀdipole
interactions between the eight NO2 groups that approach each other closely in the
vase-conformation. Dipolar repulsion between the NO2 groups presumably also
prevents the formation of face-to-face velcraplex-type dimers.

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Scheme 5. Synthesis of Cavitands 17 and 18
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a) 3a (1 equiv.), CH2BrCl (4 equiv.), K2CO3 (2.5 equiv.), Me2SO, 558, 48 h; 55%. b) 5a (1 equiv.), CH2BrCl
(10 equiv.), K2CO3 (4 equiv.), Me2SO, 558, 48 h; 47%.
Scheme 6. Synthesis of the Octanitrocavitand 19
a) 1,2-Difluoro-3,4-dinitrobenzene, NEt3, DMF, 708, 20 h; 51%.
2.2. Leg-Modified Cavitands. The visualization of single cavitand molecules and the
construction of practical devices require immobilization on various types of solid
supports. Therefore, a substantial effort in our research program is aimed at the
synthesis of cavitands suitable for surface immobilization. Previously reported
modifications include the introduction of HO- [18] or NH2-terminated legs for i)
enhancing the solubility in aqueous media [3d], ii) covalent bonding to surfaces [19],
and iii) coordination studies [20].
Cavitand 20 with four 3,5-di(tert-butyl)phenyl legs was prepared, since these legs
had previously been shown to provide good adsorption of large molecules, such as
porphyrins, on Cu surfaces for STM imaging [21]. The preparation of 20 started from
3,5-di(tert-butyl)phenylacetonitrile [22] that was converted via ester 21 into aldehyde
22 (Scheme 7). Acid-catalyzed condensation of 22 with resorcinol provided octol 23 in

Fig. 5. a) X-Ray crystal structure of octanitrocavitand 19 in a view onto the large kite surface. Atomic displacement parameters obtained at 253K are drawn at the 30%
probability level. Intramolecular O ¥¥¥ O distances [ä]: O(20) ¥¥¥ O(20a), 15.65; O(47) ¥¥¥ O(47a), 15.91; O(19) ¥¥¥ O(48), 13.63. Enclathrated acetone molecules are not
shown. b) Packing diagram of 19 featuring columnar head-to-tail stacking.

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Scheme 7. Synthesis of Cavitand 20
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a) HCl/MeOH, reflux, 3d; 99%. b) DIBAL-H, hexane, À788, 3h; 58%. c) Conc. HCl, EtOH, 608, 5 d; 35%. d)
2,3-Dichloroquinoxaline, Cs2CO3, DMF, 608, 3d; 68%. DIBAL-H ˆ diisobutylaluminum hydride.
35% yield, and subsequent bridging with 2,3-dichloroquinoxaline afforded cavitand 20
in 68% yield [4]. The molecular structure of 20 in the crystal has been previously
reported [4]; Fig. 6 depicts the head-to-tail arrangements of the cavitand vases in the
crystal lattice, leading to infinite columns, as already described for cavitands 2b (in the
vase-form) and 19 (in the kite-form). A view into these infinite columns reveals narrow
channels spanning the crystal lattice.
Fig. 6. Packing diagram of cavitand 20

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Cavitand 24, with carboxylate legs, was prepared for Langmuir monolayer
formation on an aqueous subphase. Rosenmund reduction of the acyl chloride of
monomethyl glutarate gave aldehyde 25 that was condensed with resorcinol to afford
octol 26 in 44% yield. Subsequent bridging with 2,3-dichloroquinoxaline provided 24 in
13% yield (Scheme 8). Attempts to hydrolyze the methyl ester legs proved to be
fruitless; they either led to decomposition of the cavitand or left the ester intact
(K2CO3, Li2CO3, or LiOH in H2O/THF 1:3).
Scheme 8. Synthesis of Cavitand 24
a) Pd/C, H2, 2,6-dimethylpyridine, THF, 208, 24 h. b) Resorcinol, conc. HCl, MeOH, 608, 2 d; 44% (steps a and
b). c) 2,3-Dichloroquinoxaline, Cs2CO3, DMF, 608, 2 d; 13%.
Crystals of 24 were obtained by slow evaporation of a MeCN/CHCl3 solution. The
X-ray crystal-structure analysis at 293K showed the cavitand in the vase-conformation
with an asymmetric cavity (Fig. 7). The unit-cell contains pairs of perpendicularly
aligned cavitands making tail-to-tail contacts. Disordered solvent (MeCN and,
probably, H2O) is localized within the cavity and among the ester legs.
Alkyl-thioether legs were selected due to their well-known affinity for gold surfaces
under formation of stable self-assembled monolayers (SAMs) [23][24]. Cavitands 27
and 28 with alkyl-thioether legs [5] of different length were constructed employing
slightly different synthetic strategies. Cavitand 27 was synthesized by acid-catalyzed
condensation of resorcinol with the unsaturated aldehyde 29, followed by bridging the
resulting octol 30 to give 31 featuring legs with terminal double bonds (Scheme 9). The
thioether moiety was introduced in the last step by 9-BBN-catalyzed radical addition of
decane-1-thiol to the olefinic legs. Cavitand 28 with shorter legs was prepared by direct
condensation of the thioether-containing aldehyde 32, obtained by oxidation of alcohol
33, with resorcinol, followed by bridging the resulting octol 34 (Scheme 10). SAMs
formed by 31 on Au(111) were successfully prepared and imaged by UHV-STM at the
molecular level showing a well-ordered monolayer [5]. On the other hand, cavitand 28,
with shorter legs, afforded only poorly ordered SAMs.
3. Conclusions. A series of Cram-type resorcin[4]arene-derived cavitands with
modified cavity walls and legs were prepared with the aim to investigate in detail the
conformational vaseÀkite switching in bulk solution as well as at the level of single
molecules immobilized on surfaces. Initial STM studies of monolayers on gold surfaces

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Fig. 7. ORTEP Representation of cavitand 24 with atomic displacement parameters shown at the 30% probability
level (293K). MeCN included within the cavity and solvent present among the ester tails are removed for
clarity. Intramolecular N ¥¥¥ N distances [ä]: N(17) ¥¥¥ N(102), 4.18; N(24) ¥¥¥ N(43), 4.30; N(50) ¥¥¥ N(69), 4.22;
N(76) ¥¥¥ N(95), 4.47.
have already been reported [5], and a subsequent paper will present a detailed
spectroscopic analysis of the scope and limitations of vaseÀkite switching in solution
[10]. The novel substitution patterns of cavitands 15 and 16 with differential wall
components open multiple opportunities for future functionalization. As an example,
additional recognition sites could be attached (instead of the dye labels in 15 and 16)
for enhancing the selectivity for specific guests encapsulated in the deep cavitand
cavity. Modification of the legs provided cavitands for surface immobilization and
LangmuirÀBlodgett film formation; vaseÀkite switching on surfaces and in mono-
layers is currently investigated in collaborative work by a variety of physical methods.
This paper reports the first X-ray structural analysis of a resorcin[4]arene-based
cavitand (19) in the kite-conformation. Consequently, the two different conformational

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Scheme 9. Synthesis of Cavitand 17
a) Conc. HCl, EtOH, 208, 25 h; 93%. b) 2,3-Dichloroquinoxaline, Cs2CO3, Me2SO, 208, 2 d; 44%. c) Decane-1-
thiol, 9-BBN, THF, 208, 2 d; 74%. 9-BBN ˆ 9-Borabicyclo[3.3.1]nonane.
Scheme 10. Synthesis of Cavitand 28
a) 9-BBN, THF, 208, 3h; 99%. b) PCC, CH2Cl2, 208, 5 h; 31%. c) Conc. HCl, EtOH, 608, 24 h; 99%. d) 2,3-
Dichloroquinoxaline, Cs2CO3, Me2SO, 208, 4 d; 52%. PCC ˆ pyridinium chlorochromate.
states are now structurally well-characterized in the solid state, which also provides a
sound basis for the interpretation of the results of switching studies in solution [10] and
at the single-molecule level.
Support by the Swiss National Science Foundation, via the NFP −Supramolecular Functional Materials× and
the NCCR −Nanoscience× is gratefully acknowledged. Y. Y. thanks the Japan Science Technology Corporation
Overseas Fellowship Program for a postdoctoral fellowship.
Experimental Part
General. Reagent-grade solvents and reagents were purchased and used without further purification
(except for 2,3-dichloroquinoxaline that was recrystallized from EtOH or MeOH). Octols 1a 1c were prepared
according to [13]; they were purified by recrystallization (2 Â) from MeOH (1a and 1b) or MeOH/EtOH 4 :1
(1c; for X-ray, see Fig. 2) and dried under high vacuum over P2O5 to afford the products as slightly pinkish
powders. Diol 3a was prepared according to [2b], and pyrazine derivatives 9 and 10 according to [1c]. Cavitands
2a [2b], and 2b and 2c [1b] have been previously reported (for the X-Ray crystal structure of 2b, see Fig. 3). All
reactions were carried out under Ar or N2 atmosphere. Flash chromatography (FC): SiO2 from Fluka or Merck
230 400 mesh (particle size 40 63 mm). Anal. TLC: precoated SiO2 glass plates with F-254 fluorescent
indicator; visualization with UVlight at 254 or 366 nm. M.p.: B¸chi Melting Point B-540; uncorrected. The m.p.

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of the highly colored BODIPY dyes could not be accurately determined. UV/VIS [nm]: Varian Cary-500 Scan
spectrophotometer; lmax in nm (e in mÀ1 cmÀ1). Fluorescence: Instruments S. A. Fluorolog-3 spectrofluorometer.
1
IR [cmÀ1]: Perkin-Elmer 1600-FTIR; in CCl4 or in KBr pellets. H-, 13C-, and 19F-NMR spectra [ppm]: Varian
Mercury-300 spectrometers at r.t.; internal references [ppm]: CDCl3: 7.26 (1H), 77.23( 13C); CD2Cl2: 5.32 (1H),
1
53.80 (13C); (CD3)2CO: 2.05 (1H), 29.80 (13C); CD3OD: 3.31 (1H), 49.15 (13C); (D8)THF (C4D8O): 1.73( H),
25.20 (13C); CFCl3 was used as a reference for 19F-NMR (0.00 ppm). FT-ICR-MALDI-MS: Ion Spec Ultima FT-
ICR-MS (337-nm N2-laser system); matrix: DHB (2,3-hydroxybenzoic acid) or DCTB ({(2E)-3-[4-(tert-
butyl)phenyl]-2-methylprop-2-enylidene}malonitrile). EI-MS: VG Analytical Tribrid, USA. FAB-MS: VG
Analytical ZAB2-SEQ, USA. Elemental analyses were performed by the Mikrolabor at the Laboratorium f¸r
Organische Chemie, ETH Z¸rich.
r-11,c-13,c-29,c-36-Tetrahexyl-7,10 :12,15 :24,27:29,32-tetraethano-8,31:14,25-dimethano-11H,28H-[1,4,14,17]-
tetraoxacyclohexacosino[2,3-b :15,16-b']diquinoxaline-36,38,42,43-tetrol (4a) and r-11,c-13,c-29,c-36-Tetrahexyl-
9,15-(methano[1,3]benzenomethano)-11H,13H-benzo[1'',2'':5,6;-5'',4'':5',6']bis[1,4]benzodioxonino[2,3-b :2',3'-
b']diquinoxaline-8,16,33,35-tetrol (5a). To a degassed (freeze-pump) soln. of 1a (2.48 g, 3.01 mmol) in Me2SO
(40 ml), K2CO3 (0.416 g, 3.01 mmol) and 2,3-dichloroquinoxaline (1.20 g, 6.02 mmol) were added, and the
mixture was stirred for 1 h. More K2CO3 (0.832 g, 6.02 mmol) was added, and stirring under Ar was continued
for 18 h at r.t. and 6 h at 508. After cooling, the brown soln. was added to H2O (50 ml), and the pH was adjusted
to 6 7 by addition of 1m HCl. The pink precipitate formed was isolated by filtration, washed with H2O (50 ml),
and dried under high vacuum over P2O5. FC (SiO2; CH2Cl2/AcOEt 95 :5 ! 85 :5) afforded 2a (107 mg, 2.7%) 3a
(603mg, 16.6%), 4a (103mg, 3.2%), and 5a (637 mg, 19.6%). Data of 4a: Rf (SiO2; CH2Cl2/AcOEt 90 :10) 0.3.
M.p. > 2858 (dec.). IR (KBr): 3404 (br.), 2927, 2857, 1616, 1584, 1490, 1466, 1412, 1335, 1281, 1224, 1169, 1073,
1
894, 858, 760, 606. H-NMR ((CD3)2CO, 300 MHz): 0.88 0.94 (m, 12 H); 1.25 1.48 (m, 32 H); 2.36-2.45 (m,
8 H); 4.56 (t, J ˆ 7.8, 2 H); 5.51 (t, J ˆ 7.8, 2 H); 7.15 (s, 4 H); 7.27 7.32 (m, 4 H); 7.55 7.60 (m, 4 H); 7.75 (s,
4 H); 9.04 (s, 4 H). 13C-NMR ((CD3)2CO, 75 MHz): 14.36; 23.35; 28.88; 28.97; 32.69; 32.73; 33.99; 34.79; 34.96;
110.93; 125.33; 127.99; 129.62; 130.11; 131.69; 139.92; 152.70; 152.93; 153.08. HR-MALDI-MS (DHB):
‡
‡
1099.5568 ([M ‡ Na] , C68H76N4O8Na ; calc.: 1099.5555). Data of 5a: Rf (SiO2; CH2Cl2/AcOEt 85 :15) 0.3.
M.p. > 2708 (dec.). IR (KBr): 3416 (br.), 2927, 2857, 1619, 1585, 1491, 1414, 1336, 1285, 1235, 1153, 1119, 1078,
899, 852, 759, 607. 1H-NMR ((CD3)2CO, 300 MHz): 0.86 0.95 (m, 12 H); 1.24 1.50 (m, 32 H); 2.21 2.39 (m,
4 H); 2.41 2.51 (m, 4 H); 4.30 (t, J ˆ 8.1, 2 H); 5.51 (t, J ˆ 8.1, 2 H); 6.18 (s, 1 H); 7.13( s, 2 H); 7.50 (s, 1 H);
7.62 7.81 (m, 8 H); 7.95 (s, 1 H); 8.08 8.11 (m, 2 H); 8.36 (s, 1 H); 8.72 (s, 4 H). 13C-NMR ((CD3)2CO,
75 MHz): 14.34; 14.38; 23.33; 23.36; 28.87; 28.97; 32.60; 32.71; 34.08; 34.52; 35.15; 103.49; 110.73; 118.70; 124.39;
125.107; 125.62; 125.75; 128.37; 128.72; 130.09; 130.19; 130.47; 130.98; 137.88; 140.33; 140.38; 152.08; 152.80;
‡
‡
153.29; 153.37. HR-MALDI-MS (DHB): 1099.5563 ([M ‡ Na] , C68H76N4O8Na ; calc.: 1099.5555).
5,6-Dichloropyrazine-2,3-dicarboxylic Acid 4-(tert-Butyl)phenylimide (6). To 10 (0.197 g, 0.90 mmol) in
THF (3ml), 4-( tert-butyl)aniline (0.144 ml, 0.90 mmol) was added, and the mixture was stirred for 2 h at r.t.
under Ar. Oxalyl chloride (0.085 ml, 0.99 mmol) and pyridine (0.160 ml, 1.98 mmol) were added, and the
mixture was heated to 508 for 12 h. After filtration, the mixture was evaporated to dryness, and the residue was
co-evaporated with heptane (3Â) to remove traces of pyridine. FC (SiO2; CH2Cl2/cyclohexane 3:1) gave 6
(279 mg, 89%). Pale-yellow crystals. M.p. 268 268.58. Rf (SiO2; CH2Cl2/cyclohexane 3:1) 0.25. 1H-NMR
(CDCl3, 300 MHz): 1.36 (s, 9 H); 7.3 3 7.3 8m(, 2 H); 7.53 7.58 ( m, 2 H). 13C-NMR (CDCl3, 75 MHz): 31.54;
35.15; 125.94; 126.60; 127.53; 143.24; 152.48; 154.09; 161.34.
7-[4-(tert-Butyl)phenyl]-60-endo,64-endo,68-endo,72-endo-tetrahexyl-2,12,16,27,31,42,46,57-octaoxa-
4,7,10,18,25,33,40,48,55-nonaazaheptadecacyclo[56.15.1.159,73.03,11.05,9.013,71.015,69.017,26.01 9,24.028,67.030,65.032,41.034,39.043,63
.
045,61.047,56.049,54]pentaheptaconta-1(73),3,5(9),10,13,15(69),17,19(24),20,22,25,28,30(65),32,34(39),35,37,40,43,
45(61),47,49(54),50,52,55,58(74),59(75),62,66,70-triacontaene-6,8-dione (7). To 3a (0.081 g, 0.067 mmol) and 6
(0.024 g, 0.067 mmol) in degassed Me2SO (2.5 ml), K2CO3 (0.012 g, 0.084 mmol) was added, and the mixture
was stirred under Ar at r.t. for 40 h. After addition of H2O, the precipitate formed was isolated by filtration,
washed with H2O (5 ml), and dried under vacuum over P2O5. FC (SiO2; CH2Cl2/AcOEt 100 :0 ! 98 :2)
afforded 7 (65 mg, 66%). Yellowish powder. Rf (SiO2; CH2Cl2/AcOEt 98 :2) 0.43. M.p. > 3408 (dec.). IR (KBr):
3070, 2955, 2927, 2858, 1795, 1742, 1606, 1570, 1516, 1482, 1414, 1362, 1333, 1265, 1223, 1159, 1118, 1091, 1066,
913, 898, 761, 604. 1H-NMR (CDCl3, 300 MHz): 0.90 0.96 (m, 12 H); 1.27 1.53( m, 32 H); 1.43 (s, 9 H); 2.20
2.32 (br. m, 8 H); 5.46 (t, J ˆ 7.8, 1 H); 5.50 5.59 (m, 3H); 7.11 7.15 ( m, 2 H); 7.20 (s, 2 H); 7.23( s, 2 H); 7.33
7.60 (m, 8 H); 7.81 7.93( m, 6 H); 8.13( s, 2 H); 8.16 (s, 2 H). 13C-NMR (CDCl3, 75 MHz): 14.42; 22.99; 28.21;
29.67; 31.65; 32.16; 32.57; 32.75; 34.66; 35.18; 118.53; 118.96; 123.50; 123.80; 125.92; 126.35; 127.58; 127.87;
128.08; 128.70; 129.23; 129.46; 135.41; 135.55; 135.81; 136.85; 139.62; 139.76; 141.14; 152.05; 152.16; 152.24;

3664
Helvetica Chimica Acta Vol. 86 (2003)
‡
‡
152.37; 152.63; 152.79; 152.87; 158.44; 161.77. HR-MALDI-MS (DHB): 1480.6805 (MH , C92H90N9O10 ; calc.:
1480.6805).
7,21-Bis[4-(tert-butyl)phenyl]-59-endo,63-endo,67-endo,71-endo-tetrahexyl-2,12,16,26,30,41,45,56-octaoxa-
4,7,10,18,21,24,32,39,47,54-decaazaheptadecacyclo[55.15.1.158,72.03,11.05,9.013,70.015,68.0 17,25.019,23.027,66.029,64.031,40.033,38
.
042.62.044,60.046,55.048,53]tetraheptaconta-1(72),3,5(9),10,13,15(68),17,19(23),24,27,29(64),31,33(38),34,36,39,42,44(60),
46,48(53),49,51,54,57(73),58(74),61,65,69-octacosaene-6,8,20,22-tetrone (8). To 5a (0.060 g, 0.056 mmol) and 6
(0.039 g, 0.11 mmol) in degassed Me2SO (2 ml), K2CO3 (0.019 g, 0.139 mmol) was added, and the mixture was
stirred under Ar at r.t. for 24 h. H2O (5 ml) was added, and the formed precipitate was isolated by filtration.
Washing with H2O (5 ml), drying under vacuum over P2O5, and FC (SiO2; CH2Cl2/AcOEt 100 :0 ! 97:3)
afforded 8 (46 mg, 50%). Yellowish powder. Rf ˆ (SiO2; CH2Cl2/AcOEt 98 :2) 0.45. M.p. > 3508 (dec.). IR
(KBr): 3073, 2956, 2927, 2859, 1797, 1741, 1696, 1579, 1517, 1483, 1413, 1369, 1333, 1265, 1223, 1202, 1160, 1090,
1065, 914, 900, 817, 764; 603. 1H-NMR ((D8)THF, 300 MHz): 0.93 0.97 (m, 12 H); 1.36 1.54 (m, 32 H); 1.43 (s,
18 H); 2.36 2.47 (m, 8 H); 5.67 (t, J ˆ 8.1, 2 H); 5.78 (t, J ˆ 8.1, 2 H); 7.04 7.09 (m, 4 H); 7.32 7.60 (m, 12 H);
7.96 7.99 (m, 5 H); 8.24 8.25 (m, 3 H). 13C-NMR ((D8)THF, 75 MHz): 14.34; 23.47; 28.81; 28.85; 30.06; 30.11;
31.72; 32.77; 32.92; 34.93; 35.04; 35.29; 119.61; 119.99; 124.18; 124.63; 125.28; 125.95; 127.11; 128.38; 129.38;
129.64; 129.86; 130.17; 136.57; 136.72; 137.21; 137.76; 140.15; 140.27; 142.62; 142.96; 151.39; 152.66; 152.92;
‡
‡
153.07; 153.47; 153.57; 157.60; 157.85; 161.57; 162.27. HR-MALDI-MS (DHB): 1631.7306 (MH , C100H99N10O12
;
calc.: 1631.7444).
2,8-Diethyl-5,5-difluoro-1,3,7,9-tetramethyl-10-(4-nitrophenyl)-dipyrrolo[1,2-c :2,1-f][1,3,2]diazaborinin-4-
ium-5-uide (11). A soln. of 2,4-dimethyl-3-ethyl-1H-pyrrole (3.21 g, 26.1 mmol) and 4-nitrobenzylaldehyde
(1.97 g, 13.0 mmol) in CH2Cl2 (500 ml) was degassed (bubbling N2 for 1 h), and TFA (0.10 ml, 1.3mmol) was
added. After stirring for 2 h at r.t., the mixture was washed with sat. aq. NaHCO3 soln., H2O, and sat. aq. NaCl
soln., dried (Na2SO4), and evaporated to yield the intermediate dipyrromethane (4.98 g). This compound
(4.01 g, 10.6 mmol) was dissolved in PhMe (50 ml), and DDQ (2,3-dichloro-5,6-dicyano-p-benzoquinone,
2.41 g, 10.6 mmol) was added as a suspension in PhMe (100 ml). After stirring for 1 h at r.t., Et3N (4.4 ml,
32 mmol) was added to the black mixture, and, 10 min later, BF3 ¥ OEt2 (6.7 ml, 53mmol) was added. The
mixture was stirred at r.t. for 30 min, then heated to 508 for 1 h. After cooling, the mixture was filtered through a
short plug (SiO2; toluene), and the soln. was evaporated to dryness. FC (SiO2; PhMe CH2Cl2/cyclohexane 3:2)
gave 11 (1.71 g, 38%). Dark-red powder; purple soln. in CHCl3. M.p. 193.5 1968. Rf (SiO2; CH2Cl2/cyclohexane
3:2) 0.4. UV/VIS (CHCl 3): 533 (70000). Fluorescence (CHCl3): 540. IR (CCl4): 2966, 2930, 2873, 2853, 1600,
1543, 1530, 1475, 1411, 1388, 1346, 1320, 1192, 1161, 1114, 1083, 1054, 980, 856. 1H-NMR (CDCl3, 300 MHz): 0.98
(t, J ˆ 7.5, 6 H); 1.26 (s, 6 H); 2.32 (q, J ˆ 7.5, 4 H); 2.54 (s, 6 H); 7.51 7.55 (m, 2 H); 8.35 8.40 (m, 2 H).
13C-NMR (CDCl3, 75 MHz): 12.32; 12.91; 14.88; 17.36; 77.43; 124.36; 129.99; 133.57; 136.88; 137.76; 142.92;
‡
148.25; 154.99. 19F-NMR (CDCl3, 282.5 MHz): À 145.96 (q, J ˆ 35). HR-MALDI-MS (DHB): 425.2083 (M ,
‡
C23H26BF2N3O2 ; calc.: 425.20807). X-Ray: see Fig. 4.
10-[4-Aminophenyl]-2,8-diethyl-5,5-difluoro-1,3,7,9-tetramethyldipyrrolo[1,2-c :2,1-f][1,3,2]diazaborinin-4-
ium-5-uide (12). To 11 (485 mg, 1.14 mmol) in CH2Cl2/EtOH 1 :1 (30 ml), Pd/C 10% (62 mg) was added, and
the mixture was stirred under H2 for 12 h. Filtration through Celite, evaporation to dryness, and FC (SiO2;
CH2Cl2) afforded 12 (301 mg, 67%). Orange powder; bright-orange soln. in CHCl3. M.p. 280-2858 (dec.). Rf
(SiO2; CH2Cl2) 0.47. UV/VIS (CHCl3): 526 (71000). Fluorescence (CHCl3): 536. IR (KBr): 3507, 3415, 2962,
2925, 2869, 1620, 1529, 1474, 1402, 1318, 1276, 1193, 1161, 1114, 1083, 1055, 1016, 976, 867, 831, 798, 761, 707, 659,
612, 534. 1H-NMR (CDCl3, 300 MHz): 0.98 (t, J ˆ 7.5, 6 H); 1.40 (s, 6 H); 2.31 (q, J ˆ 7.5, 4 H); 2.52 (s, 6 H); 3 .82
(br. s, 2 H); 6.75 6.80 (m, 2 H); 6.99 7.03( m, 2 H). 13C-NMR (CDCl3, 75 MHz): 12.26; 12.80; 14.99; 17.41;
115.55; 125.71; 129.33; 131.47; 132.58; 138.62; 141.13; 146.90; 153.26. 19F-NMR (CDCl3, 282.5 MHz): À145.29
‡
‡
(q, J ˆ 35). HR-MALDI-MS (DHB): 395.2341 (M , C23H28BF2N3 ; calc.: 395.23389). Anal. calc. for
C23H28BF2N3 (395.296): C 69.88, H 7.14, B 2.73, F 9.61, N 10.63; found: C 69.71, H 6.91, N 10.47.
10-[4-(2,3-Dichloro-5,7-dioxo-6,7-dihydro-5H-pyrrolo[3,4-b]pyrazin-6-yl)phenyl]-2,8-diethyl-5,5-difluoro-
1,3,7,9-tetramethyldipyrrolo[1,2-c :2,1-f][1,3,2]diazaborinin-4-ium-5-uide (13). To 7 (0.109 g, 0.497 mmol) in
THF (4 ml), 12 (0.187 g, 0.473mmol)) was added, and the soln. was stirred for 1 h at r.t. under Ar. Oxalyl
chloride (0.048 ml, 0.57 mmol) and pyridine (0.115 ml, 1.42 mmol) were added, and the mixture was heated to
508 for 12 h. The soln. obtained after filtration was evaporated to dryness, and the residue co-evaporated with
heptane (3Â) to remove traces of pyridine. FC (SiO2; CH2Cl2) afforded 13 (212 mg, 72%). Red powder; bright-
purple soln. in CHCl3. M.p. 285 2958 (dec.). Rf ˆ (SiO2; CH2Cl2) 0.55. UV/VIS (CHCl3): 530 (73000).
Fluorescence (CHCl3): 537. IR (KBr): 2965, 2930, 2871, 1803, 1740, 1541, 1518, 1477, 1388, 1373, 1320, 1272, 1234,
1194, 1161, 1116, 1067, 979, 803, 760, 702, 536. 1H-NMR (CDCl3, 300 MHz): 0.99 (t, J ˆ 7.5, 6 H); 1.35 (s, 6 H);
2.31 (q, J ˆ 7.5, 4 H); 2.52 (s, 6 H); 7.48 7.52 (m, 2 H); 7.62 7.66 (m, 2 H). 13C-NMR (CDCl3, 75 MHz): 12.34;

Helvetica Chimica Acta Vol. 86 (2003)
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12.87; 14.94; 17.42; 77.43; 126.70; 129.56; 130.67; 131.03; 133.26; 136.62; 138.35; 143.01; 154.34; 160.92. 19F-NMR
‡
‡
(CDCl3, 282.5 MHz): À145.14 (q, J ˆ 35). HR-MALDI-MS (DHB): 595.1523 (M , C29H26BCl2F2N5O2 ; calc.
595.15192).
Compound 14 (for nomenclature and full characterization, see [9]). Preparation as described for 7 from 3a
(0.060 g, 0.050 mmol), 13 (0.030 g, 0.050 mmol), and K2CO3 (0.0086 g, 0.062 mmol) in Me2SO (2.5 ml). CC
(SiO2; CH2Cl2/AcOEt 100 :0 ! 98 :2) afforded 14 (63mg, 73%). Bright-red solid.
Compound 15 (for nomenclature and full characterization, see [9]). To a degassed soln. of 4a (0.018 g,
0.0167 mmol) and 13 (0.022 g, 0.0367 mmol) in Me2SO (1 ml), K2CO3 (0.0051 g, 0.0367 mmol) was added. After
stirring under Ar at r.t. for 4 h, additional K2CO3 (0.0051 g, 0.0367 mmol) was added. A dark-red precipitate
formed within 30 min, H2O (5 ml) was added, and the precipitate was isolated by filtration, washed with H2O
(5 ml), and dried under vacuum over P2O5. FC (SiO2; CH2Cl2/AcOEt 100 :0 ! 97:3) provided 15 (19 mg, 54%).
Bright-red solid.
Compound 16 (for nomenclature and full characterization, see [9]). Preparation as described for 8 from 5a
(0.035 g, 0.032 mmol), 13 (0.038 g, 0.064 mmol), and K2CO3 (0.009 g, 0.064 mmol) in Me2SO (1.5 ml). FC (SiO2;
CH2Cl2/AcOEt 100 :0 ! 97:3) gave 16 (45 mg, 66%). Bright-red solid.
52-endo,56-endo,60-endo,64-endo-Tetrahexyl-2,4,8,19,23,34,38,49-octaoxa-10,17,25,32,40,47-hexaazapenta-
decacyclo[48.15.1.151,65.05,63.07,61.09,18. 011,16.020,59.022,57.024,33.026,31.035,55.037,53.039,48.041,46]heptahexaconta-1(65),5,7(61),
9,11(16),12,14,17,20,22(57),24,26(31),27,29,32,35,37 (53),39,41(46),42,44,47,50(66),51(67),54,58,62-heptacos-
aene (17). To a degassed soln. of 3a (0.088 g, 0.073mmol) in Me 2SO (4 ml), K2CO3 (0.015 g, 0.109 mmol)
and CH2BrCl (0.019ml, 0.29 mmol) were added, and the mixture was stirred for 12 h at 458 under Ar. Additional
K2CO3 (0.10 g, 0.073mmol) and CH 2BrCl (0.019ml, 0.29 mmol) were added, and the mixture was stirred at 558
for 30 h. After addition of cold H2O (10 ml), the precipitate formed was isolated by filtration and dried (P2O5).
FC (SiO2; CH2Cl2/AcOEt 100 :0 ! 97:3) provided 17 (49 mg, 55%). Colorless amorphous solid. Rf (SiO2;
CH2Cl2/cyclohexane 3 :1) 0.37. M.p. 3358 (dec.). IR (KBr): 3067, 2954, 2927, 2857, 1607, 1579, 1570, 1485, 1415,
1
1334, 1276, 1222, 1162, 1118, 1068, 972, 913, 896, 759, 606. H-NMR (CDCl3, 300 MHz): 0.91 0.98 (m, 12 H);
1.32 1.55 (m, 32 H); 2.22 2.37 (m, 8 H); 4.10 (d, J ˆ 7.2, 1 H); 4.71 (t, J ˆ 8.1, 1 H); 5.66 (d, J ˆ 7.2, 1 H); 5.71
(m, 3H); 7.22 ( s, 2 H); 7.23( s, 2 H); 7.24 (s, 2 H); 7.44 7.59 (m, 6 H); 7.68 7.72 (m, 2 H); 7.86 7.93( m, 4 H);
8.29 (s, 2 H). 13C-NMR (CDCl3, 75 MHz): 14.30; 22.89; 28.07; 28.18; 29.62; 29.70; 30.62; 32.09; 32.34; 32.55;
34.30; 34.46; 36.55; 99.63; 117.38; 118.92; 121.88; 123.94; 128.02; 129.28; 129.36; 129.49; 135.42; 136.12; 136.53;
138.66; 139.90; 139.94; 152.18; 152.67; 152.88; 152.92; 153.09; 155.44. HR-MALDI-MS (DHB): 1215.5966
‡
‡
(MH , C77H79N4O8 ; calc.: 1215.59602).
43-endo,47-endo,51-endo,55-endo-Tetrahexyl-2,4,8,10,14,25,29,40-octaoxa-16,23,31,38-tetraazatridecacyclo-
[39.15.1.142,56.05,54.07,52.011,50.013,46.015,24.017,22.026,46.028,44.030,39.032,37]octapentaconta-1(56),5,7(52),11,13(48),15,17(22),
18,20,23,26,28(44),30,32(37),33,35,38,41(57),42(58),45,49,53-docosaene (18). To a degassed soln. of 5a
(0.070 g, 0.066 mmol) in Me2SO (3ml), K 2CO3 (0.036 g, 0.26 mmol) and CH2BrCl (0.042 ml, 0.65 mmol) were
added, and the mixture was stirred under Ar for 12 h at 558. Additional K2CO3 (0.018 g, 0.13mmol) and
CH2BrCl (0.021 ml, 0.325 mmol) were added, and the mixture was stirred for 24 h. After addition of cold H2O
(10 ml), the precipitate formed was isolated by filtration and dried (P2O5). FC (SiO2; CH2Cl2/AcOEt 100 :0 !
99.5 :0.5) afforded 18 (34 mg, 47%). Colorless powder. Rf (SiO2; CH2Cl2/cyclohexane 3:1) 0.42. M.p. 295 8
(dec.). IR (KBr): 3068, 2954, 2927, 2857, 1607, 1579, 1486, 1414, 1333, 1284, 1261, 1222, 1118, 1073, 973, 914, 896,
760, 719, 606. 1H-NMR (CDCl3, 300 MHz): 0.89 0.97 (m, 12 H); 1.30 1.57 (m, 32 H); 2.19 2.35 (m, 8 H); 4.16
(d, J ˆ 7.2, 2 H); 4.71 (t, J ˆ 8.1, 2 H); 5.65 (d, J ˆ 7.2, 2 H); 5.73( t, J ˆ 8.1, 2 H); 6.33 (s, 1 H); 7.14 (s, 1 H); 7.19 (s,
1 H); 7.21 (s, 2 H); 7.3 2 (s, 2 H); 7.55 7.67 (m, 4 H); 7.83(br. d, J ˆ 7.8, 2 H); 8.01 (br. d, J ˆ 7.8, 2 H); 8.34 (s,
1 H). 13C-NMR (CDCl3, 75 MHz): 14.41; 22.98; 23.01; 28.14; 28.30; 29.73; 29.79; 30.51; 32.18; 32.21; 32.28;
34.54; 36.60; 99.54; 116.61; 117.15; 118.72; 120.28; 121.97; 124.33; 128.03; 129.38; 129.65; 135.34; 136.25; 137.86;
‡
139.01; 139.88; 151.95; 152.46; 152.76; 153.08; 154.80; 155.39. HR-MALDI-MS (DHB): 1101.5748 (MH ,
‡
C70H77N4O8 ; calc.: 1101.57423).
2,3 :2',3':2'',3'':2''',3'''-{2-endo,8-endo,14-endo,20-endo-Tetrahexylpentacyclo[19.3.1.13,7.19,13.115,19]octacosa-
1(25),3,5,7(28),9,11,13(27),15,17,19(26),21,23-dodecaene-4,24:6,10 :12,16 :18,22-octayloctaoxy}tetrakis(5,6-di-
nitropyrazine) (19). To 1a (0.890 g, 1.08 mmol) and 1,2-difluoro-3,4-dinitrobenzene (0.969 g, 4.75 mmol) in
DMF (30 ml), Et3N (2.41ml, 17.3mmol) was added dropwise, and the mixture was heated to 70 8 for 12 h. After
cooling, the mixture was poured into 1m HCl (200 ml), and the precipitate formed was isolated by filtration,
washed with 1m HCl (200 ml), H2O (200 ml), and dried (P2O5). FC (SiO2; CH2Cl2) afforded 19 (814 mg, 51%).
Slightly yellowish powder. M.p. 295 3158 (dec.). Rf (SiO2; CH2Cl2) 0.65; Rf ˆ (SiO2; CH2Cl2/cyclohexane 3:1)
0.13. IR (KBr): 3056, 2930, 2858, 1594, 1542, 1486, 1362, 1326, 1287, 1192, 1142, 1078, 899, 851, 823, 752, 653.
1H-NMR (CDCl3, 300 MHz): 0.84 0.89 (m, 12 H); 1.09-1.19 (m, 32 H); 1.96 2.08 (m, 8 H); 3.90 3.96 (m,

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Helvetica Chimica Acta Vol. 86 (2003)
4 H); 6.21 (br. s, 2 H); 7.01 (s, 2 H); 7.02 (s, 2 H); 7.22 (br. s, 2 H); 7.63( s, 4 H); 7.66 (s, 4 H). 13C-NMR
((CD3)2CO, 75 MHz): 14.24; 23.28; 27.81; 31.85; 32.52; 37.14; 153.72 (other peaks not resolved due to
‡
‡
conformational equilibration). HR-MALDI-MS (DHB): 1503.4538 ([M ‡ Na] , C76H72N8O24Na ; calc.:
1503.45569). X-Ray: see Fig. 5.
Methyl 2-[3,5-Di(tert-butyl)phenyl]acetate (21) [25]. HCl Gas was bubbled for 20 min through a soln. of 2-
[3,5-di-(tert-butyl)phenyl]acetonitrile [22] (38.8 g, 169 mmol) in anh. MeOH (350 ml), and the mixture was
heated to reflux for 3d under Ar. Evaporation under reduced pressure gave a residue that was dissolved in
CH2Cl2 (1000 ml). The soln. was washed with 1m HCl (400 ml), dried (MgSO4), and evaporated. Filtration of
the resulting oil through a short column (5 cm SiO2; CH2Cl2) gave 21 (43.8 g, 99%). Pale-yellow oil. Rf (SiO2;
hexane/CH2Cl2 1 :1) 0.42. 1H-NMR (300 MHz, CDCl3): 1.33 (s, 18 H); 3.66 (s, 2 H); 3.70 (s, 3 H); 7.13 (d, J ˆ 1.9,
2 H); 7.3 4 (t, J ˆ 1.9, 1 H). 13C-NMR (75 MHz, CD3OD): 30.5; 34.2; 40.8; 51.0; 120.7; 123.2; 133.4; 150.8; 173.2.
‡
‡
EI-MS: 262 (M ), 247 ([M À Me] ).
2-[3,5-Di(tert-butyl)phenyl]acetaldehyde (22) [26]. To a soln. of 21 (43.8 g, 167 mmol) in hexane (350 ml),
cooled to À788, DIBAL-H (1m in hexane, 200 ml) was added via cannula under N2, and the mixture was stirred
at À788 for 3h. After cautious addition of MeOH (30 ml), the mixture was poured into sat. aq. Na/K tartrate
soln. (400 ml). AcOEt (400 ml) was added, and the mixture was stirred for 12 h. The org. layer was separated,
and the aq. layer was washed with AcOEt (2 Â 300 ml). The combined org. layers were dried (K2CO3) and
evaporated under reduced pressure. Distillation (114 1168 0.8 Torr) gave 22 (22.4 g, 58%). Yellow oil. Rf (SiO2;
CH2Cl2) 0.58. UV/VIS (MeOH): 256 (1120). IR (CH2Cl2): 2964, 1718, 1595, 1472, 1395, 1364, 1262, 1190, 1159,
1097, 1000, 892, 867, 815, 697. 1H-NMR (300 MHz, CDCl3): 1.35 (s, 18 H); 3.68 (d, J ˆ 2.4, 2 H); 7.08 (d, J ˆ 1.8,
2 H); 7.40 (t, J ˆ 1.8, 1 H); 9.77 (t, J ˆ 2.4, 1 H). 13C-NMR (75 MHz, CDCl3): 31.5; 34.9; 51.3; 121.7; 124.0; 124.4;
‡
‡
‡
131.2; 151.9; 200.3. EI-MS: 232.2 (M ), 217.2 ([M À Me] ), 203.2 ([M À CHO] ).
Compound 23 (for nomenclature and full characterization, see [4]). To resorcinol (2.47 g, 22.5 mmol) and
22 (5.20 g, 22.4 mmol) in EtOH (50 ml) at 08 under N2, conc. HCl (40 ml) was added dropwise over 30 min. The
soln. was stirred at 608 for 5 d, then poured into H2O (1500 ml). After stirring for 2 h at r.t, the precipitate
formed was collected by filtration and recrystallized (MeCN) to give 23 (2.57 g, 35%). Pale-brown solid.
Compound 20 (for nomenclature and full characterization including X-ray structure analysis (Fig. 6), see
[4]). A soln. of 22 (0.56 g, 0.43 mmol), 2,3-dichloroquinoxaline (0.39 g, 1.96 mmol), and Cs2CO3 (1.18 g,
3.62 mmol) in anh. DMF (60 ml) was stirred under N2 for 2 d at 608. After cooling, CH2Cl2 (400 ml) was added.
Washing with H2O, drying (Na2SO4), and evaporation provided a solid that was purified by FC (SiO2; CH2Cl2/
MeOH 99.5 :0.5) to give 20 (0.53g, 68%). Off-white solid.
Tetramethyl
4,4',4'',4'''-(4,6,10,12,16,18,22,24-Octahydroxypentacyclo[19.3.1.13,7.19,13.115,19]octacosa-
1(25),3,5,7(28),9,11,13(27),15,17,19(26),21,23-dodecaene-2,8,14,20-tetrayl)tetrabutanoate (26). Pd/C (10%)
(2.9 g) was flushed with H2, freshly distilled THF (900 ml) was added, and the soln. was reflushed with H2.
2,6-Dimethylpyridine (21.2 g, 198 mmol) and glutaric acid monomethyl ester chloride (29.8 g, 181 mmol) were
added, and the soln. was stirred at r.t. under H2 for 24 h. Filtration through Celite and evaporation under reduced
pressure left a residue that was taken up in CH2Cl2 (500 ml). Washing with H2O (300 ml), 1m HCl (300 ml), and
H2O (300 ml) and evaporation under reduced pressure provided 25 (25.3g). Colorless oil. 1H-NMR (300 MHz,
CDCl3): 1.80 2.30 (m, 2 H); 2.3 8 (t, J ˆ 7.5, 2 H); 2.49 2.60 (m, 2 H); 3 .68 (s, 3H); 9.79 ( t, J ˆ 1.2, 1 H). To 25
(25.3g) and resorcinol (19.9 g, 181 mmol) in MeOH (300 ml) at 0 8, conc. HCl (5 ml) was added over 30 min, and
the soln. was stirred under Ar at r.t. for 2 h, then at 608 for 2 d. The soln. was poured into H2O (1500 ml), and the
resulting cream-colored precipitate was collected by filtration and recrystallized (MeCN) to give 26 (17.59 g,
44%). White solid. M.p. 205 2108. UV/VIS (MeOH): 286 (17300). 1H-NMR (300 MHz, CD3OD): 1.58 (quint.,
J ˆ 7.5, 8 H); 2.25 (q, J ˆ 7.8, 8 H); 2.42 (t, J ˆ 7.4, 8 H); 3.66 (s, 12 H); 4.31 (t, J ˆ 7.9, 4 H); 6.23( s, 4 H); 7.24 (s,
4 H). 13C-NMR (75 MHz, CD3OD): 24.7; 34.1; 34.6; 34.8; 52.1; 104.1; 125.3; 153.2; 176.0. HR-MALDI-MS
‡
‡
(DHB): 911.3460 ([M ‡ Na] , C48H56NaO16 ; calc.: 911.3461). Anal. calc. for (C48H56O16)2 ¥ H2O ¥ MeCN
(1836.965): C 64.08, H 6.42 N 0.76; found: C 63.7, H 6.35, N 0.74.
2,3 :2',3': 2'',3'':2''',3'''-{2-endo,8-endo,14-endo,20-endo-Tetrakis[3-(methoxycarbonyl)propyl]pentacy-
clo[19.3.1.13,7.19,13.115,19]octacosa-1(25),3,5,7(28),9,11,13(27),15,17,19(26),21,23-dodecaene-4,24 :6,10 :12,16 :18,22-
octayloctaoxy}tetraquinoxaline (24). A soln. of 2,3-dichloroquinoxaline (1.51 g, 7.57 mmol), 26 (1.50 g,
1.69 mmol), and Cs2CO3 (4.50 g, 13.8 mmol) in anh. DMF (250 ml) was stirred under Ar at 608 for 2 d. The
mixture was poured into dilute aq. AcOH soln., and the resulting precipitate was collected by filtration.
Recrystallization (MeCN) gave 24 (0.305 g, 13%). Colorless solid. M.p. > 2508. UV/VIS (CHCl3): 315 (36500),
328 (32000). 1H-NMR (300 MHz, CDCl3): 1.68 1.82 (m, 8 H); 2.34 2.46 (m, 8 H); 2.54 (t, J ˆ 7.3, 8 H); 3.74 (s,
12 H); 5.65 (t, J ˆ 8.0, 4 H); 7.34 (s, 4 H); 7.44 7.51 (m, 8 H); 7.77 7.83( m, 8 H); 8.19 (s, 4 H). 13C-NMR

Helvetica Chimica Acta Vol. 86 (2003)
3667
(75 MHz, CDCl3): 23.5; 31.7; 33.7; 34.4; 51.7; 119.0; 123.8; 127.9; 129.1; 135.7; 139.8; 152.6; 152.7; 174.1. HR-
‡
‡
MALDI-MS (DHB): 1415.4494 ([M ‡ Na] , C80H64N8NaO16 ; calc.: 1415.4338). X-Ray: see Fig. 7.
2,8,14,20-Tetrakis(dec-9-enyl)pentacyclo[19.3.1.13,7.19,13.115,19]octacosa-1(25),3,5,7(28),9,11,13( 27),15,17,19(26),
21,23-dodecaene-4,6,10,12,16,18,22,24-octol (30). To resorcinol (11.2 g, 0.1 mol) and 29 (17.7 g, 0.1 mol) in EtOH
(100 ml), conc. HCl (16 ml) was added dropwise over 30 min at 08 under Ar. After stirring for 25 h at r.t., the
mixture was poured into H2O (300 ml). The precipitate formed was isolated by filtration, triturated with H2O,
and dried under vacuum at 708 for 20 h to give 30 (24.3g, 93%). Orange-colored solid. Rf ˆ (SiO2; CHCl3/
MeOH 5 :1) 0.60; Rf (SiO2; CH2Cl2/MeOH 10 :1) 0.42. M.p. > 2508 (EtOH). IR (KBr): 3316, 2924, 2866, 1639,
1617, 1504, 1461, 1436, 1367, 1344, 1300, 1267, 1194, 1166, 1150, 1083, 989, 907, 848, 828, 722, 628, 611, 556, 512.
1H-NMR ((CD3)2CO, 200 MHz): 1.20 1.70 (m, 56 H); 2.28 (m, 8 H); 4.30 (t, J ˆ 7.9, 4 H), 4.93( m, 8 H); 5.82
‡
(m, 4 H); 6.25 (s, 4 H); 7.55 (s, 4 H); 8.50 (br. s, 8 H). FAB-MS: 1040.6 (M ). HR-MALDI-MS: 1063.6995
‡
‡
([M ‡ Na] , C68H96NaO8 ; calc.: 1063.7003).
2,3 :2',3':2'',3'':2''',3'''-[2-endo,8-endo,14-endo,20-endo-Tetrakis(dec-9-enyl)pentacyclo[19.3.1.13,7.19,13.115,19]-
octacosa-1(25),3,5,7(28),9,11,13(27),15,17,19(26),21,23-dodecaene-4,24 :6,10 :12,16 :18,22-octayloctaoxy}tetra-
quinoxaline (31). A soln of 30 (2.08 g, 2.0 mmol), 2,3-dichloroquinoxaline (1.66 g, 8.0 mmol), and Cs2CO3
(2.90 g, 8.8 mmol) in dry Me2SO (70 ml) was stirred under Ar at r.t. for 2 d. The mixture was poured into ice-
water, and the brownish precipitate formed was isolated by filtration. The filtrate was extracted with CH2Cl2,
and the org. layer was washed with H2O and evaporated to provide additional solid crude product that was
combined with the first precipitate. FC (SiO2 (150 g); CH2Cl2/AcOEt 98 :2 ! 90 :10) afforded 31 (1.285 g,
44%). Colorless flakes. Rf (SiO2; CH2Cl2) 0.23; Rf ˆ (SiO2; CH2Cl2/AcOEt 20 :1) 0.66. M.p. > 2508 (CH2Cl2/
Me2CO). IR (KBr): 3066, 2925, 2852, 1711, 1639, 1606, 1570, 1482, 1416, 1400, 1361, 1265, 1222, 1160, 1117, 1061,
1
1017, 994, 950, 911, 896, 759, 722, 606, 583, 522, 461. H-NMR (CDCl3, 200 MHz): 1.20 1.50 (m, 48 H); 1.99
2.09 (m, 8 H); 2.24 (m, 8 H); 4.95 (m, 8 H); 5.53( t, J ˆ 8.2, 4 H); 5.81 (m, 4 H); 7.18 (s, 4 H); 7.40 7.49 (m, 8 H);
7.72 7.81 (m, 8 H); 8.12 (s, 4 H). 13C-NMR (CDCl3, 75 MHz): 27.8; 28.9; 29.0; 29.4; 29.5; 32.3; 33.7; 34.1; 114.2;
‡
118.7; 123.4; 127.8; 129.8; 135.8; 139.3; 139.7; 152.5; 152.6. FAB-MS: 1546 (MH ). HR-MALDI-MS: 1567.7950
‡
‡
‡
‡
([M ‡ Na] , C100H104N8NaO8 ; calc.: 1567.7875), 1545.8168 (MH , C100H105N8O8 ; calc.: 1545.8055). Anal. calc.
for C100H104N8O8 ¥ AcOEt (1634.05): C 76.44, H 6.91, N 6.86; found: C 76.15, H 6.82, N 6.78.
2,3 : 2',3': 2'',3'': 2''',3'''-{2-endo,8-endo,14-endo,20-endo-Tetrakis[10-(decylsulfanyl)delcyl]pentacyclo-
[19.3.1.13,7.19,13.115,19]octacosa-1(25),3,5,7(28),9,11,13(27),15,17,19(26),21,23-dodecaene-4,24 :6,10 :12,16 :18,22-
octayloctaoxy}tetraquinoxaline (27). To 27 (474 mg, 0.33 mmol) in freshly distilled THF (20 ml), decane-1-thiol
(0.7 ml, 3.3 mmol) was added, and the mixture was stirred under Ar at 08 for 1 h. After addition of 9-BBN (0.5m
in THF, 33 ml, 16.5 mmol), the mixture was stirred under Ar for 2 d at r.t., then poured into H2O (200 ml), and
extracted with CH2Cl2 (200 ml). Washing with H2O (2 Â 200 ml), drying (MgSO4), evaporation, and FC (SiO2
(50 g); CH2Cl2/AcOEt 99 :1 ! 50 :50) gave 27 (543mg, 0.242 mmol, 74%). Colorless powder. Rf (SiO2; CH2Cl2)
0.25. M.p. 53 55 8 (CH2Cl2/Me2CO). IR (KBr): 2924, 2851, 1482, 1417, 1336, 1266, 1160, 897, 758, 607. 1H-NMR
(CDCl3, 200 MHz): 0.86 (t, J ˆ 6.6, 12 H); 1.20 1.70 (m, 128 H); 2.22 (m, 8 H); 2.48 (m, 16 H); 5.54 (t, J ˆ 8.2,
4 H); 7.18 (s, 4 H); 7.40 7.49 (m, 8 H); 7.73 7.81 ( m, 8 H); 8.13( s, 4 H). 13C-NMR (CDCl3, 75 MHz): 14.0; 22.6;
27.8; 28.9 29.7 (15 Â ); 31.8; 32.1; 34.1; 118.8; 123.4; 127.8; 129.0; 135.8; 139.7; 152.5; 152.6. MALDI-MS: 2242.5
‡
‡
‡
‡
(MH , C140H193N8O8S4 ; calc.: 2242.3823), 2264.5 ([M ‡ Na] , C140H192N8NaO8S4 ; calc.: 2264.3643); 2281.4
‡
‡
([M ‡ K] , C140H192KN8O8S4 ; calc.: 2280.3382). Anal. calc. for C140H192N8O8S4 (2243.34): C 74.96, H 8.63,
N 4.99; found: C 74.85, H 8.41, N 5.01.
6-(Pentylsulfanyl)hexan-1-ol (33). To hex-6-en-1-ol (1.22 ml, 1.0 g, 10 mmol) in freshly distilled THF
(20 ml), 9-BBN (0.5m in THF, 100 ml, 50 mmol) was added at 08 under N2. Pentane-1-thiol (1.28 ml, 1.24 g,
10 mmol) was added at 08, and the mixture was stirred for 3h at r.t. The mixture was poured into sat. aq. NaCl
soln. (100 ml) and extracted with CH2Cl2 (3 Â 100 ml). Drying (MgSO4), evaporation, and FC (SiO2; CH2Cl2/
AcOEt 5 :2) provided 33 (2.2 g, 99%). Colorless oil. Rf ˆ (SiO2; hexane/AcOEt 2 :1) 0.35 0.38. IR (neat): 3356,
2922, 2856, 1461, 1378, 1300, 1267, 1217, 1056, 895, 728. 1H-NMR (CDCl3, 300 MHz): 0.87 (t, J ˆ 7.2, 3H); 1.20
1.64 (m, 14 H); 2.47 (t, J ˆ 7.5, 2 H); 2.49 (t, J ˆ 7.5, 2 H); 3.62 (br. m, 2 H). 13C-NMR (CDCl3, 75 MHz): 13.8;
‡
‡
‡
22.2; 25.3; 28.6; 29.3; 29.5; 31.0; 32.0; 32.1; 32.5; 62.9. EI-MS: 204 (M ), 157 ([M À MeS] ), 143([ M À EtS] ),
‡
‡
131 ([M À BuO] ), 115 ([M À BuS] ). Anal. calc. for C11H24OS (204.3737): C 64.65, H 11.84; found: C 64.59,
H 11.83.
6-(Pentylsulfanyl)hexanal (32). To a suspension of PCC (1.6 g, 7.5 mmol) and Celite (1.6 g) in freshly
distilled CH2Cl2 (20 ml), a soln. of 33 (1.02 g, 5 mmol) in freshly distilled CH2Cl2 (5 ml) was added dropwise
under Ar at r.t. After stirring for 5 h under Ar at r.t., the mixture was filtered through a pad of SiO2, which was
subsequently washed with CH2Cl2. The combined filtrates were concentrated to yield 32 (313 mg, 31%).
Colorless oil. Rf (SiO2; CH2Cl2)0.59. IR (neat): 2929, 2856, 2711, 2357, 2333, 1722, 1458, 1300, 1272, 1217, 1156,

3668
Helvetica Chimica Acta Vol. 86 (2003)
1078. 1H-NMR (CDCl3, 300 MHz): 0.87 (t, J ˆ 7.2, 3H); 1.24 1.47 ( m, 6 H); 1.50 1.69 (m, 6 H); 2.37 2.45 (m,
2 H); 2.47 (t, J ˆ 7.2, 2 H); 2.49 (t, J ˆ 7.2, 2 H); 9.75 (t, J ˆ 1.7, 1 H). 13C-NMR (CDCl3, 75 MHz): 13.8; 21.6;
‡
‡
22.2; 28.3; 29.3 (2 Â); 31.0; 31.8; 32.1; 43.7; 202.7. EI-MS: 202 (M ), 174 ([M À CO] ). Anal. calc. for C11H22OS
(202.3578): C 65.29, H 10.96; found: C 65.28, H 10.77.
2,8,14,20-Tetrakis[5-(pentylsulfanyl)pentyl]pentacyclo[19.3.1.13,7.19,13.115,19]octacosa-1(25),3,5,7 (28),9,11,13(27),
15,17,19(26),21,23-dodecaene-4,6,10,12,16,18,22,24-octol (34). To 32 (282 mg, 1.39 mmol) and resorcinol
(156 mg, 1.39 mmol) in EtOH (1.4 ml), conc. HCl (0.22 ml) was added dropwise over 30 min at 08 under N2.
The mixture was stirred at r.t. for 1 h and at 608 for 24 h, then it was poured into ice-water. The formed
precipitate was isolated by filtration and dried under vacuum for 2 d to give 34 (412 mg, 99%). Colorless
powder. M.p. > 2508 (EtOH). IR (KBr): 3254, 2927, 2856, 1618, 1500, 1450, 1367, 1328, 1294, 1256, 1211, 1167,
1089, 900, 833. 1H-NMR ((CD3)2CO, 300 MHz): 0.89 (t, J ˆ 7.1, 12 H); 1.22 1.42 (m, 24 H); 1.42 1.64 (m,
24 H); 2.27 2.35 (m, 8 H); 2.50 (t, J ˆ 7.3, 16 H); 4.30 (t, J ˆ 7.8, 4 H); 6.24 (s, 4 H); 7.55 (s, 4 H); 8.48 (s, 8 H).
13C-NMR ((CD3)2CO, 50 MHz): 14.3; 22.9; 29.6; 30.1; 30.4; 30.8; 31.8; 32.5; 32.6; 34.2; 34.3; 103.7; 125.3; 125.5;
‡
‡
152.8. HR-MALDI-MS: 1199.6497 ([M ‡ Na] , C68H104NaO8S4 ; calc.: 1199.6512).
2,3 :2',3':2'',3'':2''',3'''-{2-endo,8-endo,14-endo,20-endo-tetrakis[5-(pentylthio)pentyl]pentacyclo[19.3.1.13,7
19,13.115,19]octacosa-1(25),3,5,7(28),9,11,13(27),15,17,19(26),21,23-dodecaene-4,24 :6,10 :12,16 :18,22-octayloc-
taoxy}tetraquinoxaline (28). A soln. of 34 (133 mg, 0.113 mmol), 2,3-dichloroquinoxaline (94 mg, 0.45 mmol),
and Cs2CO3 (163mg, 0.50 mmol) in dry Me 2SO (5 ml) was stirred at r.t. under Ar for 4 d. The mixture was
poured into ice-water, and the precipitate formed was isolated by filtration, triturated with H2O, and then
dissolved in Me2CO/CH2Cl2. The soln. was dried (MgSO4) and concentrated to give a dark-brown solid that was
purified by FC (SiO2; CH2Cl2/AcOEt 98 :2 ! 80 :20) to give 28 (99 mg, 52%). Colorless flakes. M.p. 227 2308
(EtOH). IR (KBr): 3067, 2926, 2856, 1606, 1572, 1483, 1467, 1417, 1400, 1361, 1336, 1265, 1233, 1222, 1160, 1117,
1072, 1044, 1011, 950, 906, 896, 867, 757, 722, 606, 583. 1H-NMR (CDCl3, 200 MHz): 0.89 (t, J ˆ 7.1, 12 H); 1.28
1.50 (m, 24 H); 1.50 1.75 (m, 24 H); 2.27 (m, 8 H); 2.52 (t, J ˆ 7.3, 8 H); 2.55 (m, 8 H); 5.59 (t, J ˆ 8.1, 4 H); 7.18
(s, 4 H); 7.41 7.50 (m, 8 H); 7.71 7.80 (m, 8 H); 8.16 (s, 4 H). 13C-NMR (CDCl3, 50 MHz): 13.9; 22.2; 27.5; 28.7;
29.4; 29.6; 31.1; 32.1; 32.2 (2Â); 34.0; 118.9; 123.3; 127.8; 129.0; 135.7; 139.7; 152.5; 152.6. HR-MALDI-MS:
.
‡
‡
‡
‡
1703.7388 ([M ‡ Na] , C100H112N8NaO8S4
; calc.: 1703.7384), 1681.7578 (MH , C100H113N8O8S4 ; calc.:
1681.7656). Anal. calc. for C100H112N8O8S4 (1682.2724): C 71.40, H 6.71, N 6.66; found: C 71.50, H 7.02, N 6.86.
X-Ray Crystal Structure of 1c. Crystal data at 233 K for C44H56O8 ¥ 2(MeOH) ¥ MeCH2OH (Mr823.04):
monoclinic, space group C2/c (No. 15), Dc ˆ 1.207 g/cm3, Z ˆ 8, a ˆ 36.049(7), b ˆ 11.564(2), c ˆ 21.773(5) ä,
b ˆ 93.71(2)8, Vˆ 9058(3) ä3, Nonius CAD4 diffractometer, CuKa radiation, l ˆ 1.5418 ä. A crystal, obtained
by slow cooling of a MeOH/EtOH soln. (linear dimensions ca. 0.2 Â 0.18 Â 0.16 mm) was mounted at low temp.
to prevent evaporation of enclosed solvent. The structure was solved by direct methods (SIR97) [27] and refined
by full-matrix least-squares analysis (SHELXL-97) [28], by using an isotropic extinction correction, and w ˆ 1/
[s2(F2o ) ‡ (0.0933P)2 ‡ 49.1608P], where P ˆ (Fo2 ‡ 2F2c )/3. The subunit C(10)ÀC(13) and one MeOH are
disordered over two orientations. For C(11), C(12), C(13), and O(200), two sets of atomic parameters were
refined with population parameters of 0.7 and 0.3, resp. In Fig. 2, only one orientation is shown for clarity. All
heavy atoms were refined anisotropically (H-atoms of the ordered structure isotropically, whereby H-positions
are based on stereochemical considerations). Final R(F) ˆ 0.084, wR(F2) ˆ 0.241 for 626 parameters and 5047
reflections with I > 2s (I) and 2.46 < q < 56.968 (corresponding R values based on all 6098 reflections are 0.098
and 0.252 resp.). CCDC-214738.
X-Ray Crystal Structure of 2b. Crystal data at 293K for C 80H72N8O8 ¥ CH2Cl2 ¥ 2 MeCN (Mr 1440.51):
monoclinic, space group C2/c (No. 15), Dc ˆ 1.224 g/cm3, Z ˆ 4, a ˆ 19.007(14), b ˆ 17.623(13), c ˆ 24.57(2) ä,
b ˆ 109.63(6)8, Vˆ 7752(11) ä3; Picker-Stoe diffractometer, CuKa radiation, l ˆ 1.5418 ä. Prismatic crystals
(linear dimensions ca. 0.15 Â 0.1 Â 0.1 mm) were obtained by slow evaporation from MeCN/CH2Cl2. The
structure was solved by direct methods (SHELXS-86) [29] and refined by full-matrix least-squares analysis
(SHELXL-93) [30]. The subunit C(35) ÀC(36) and both MeCN molecules are disordered over two
orientations. In Fig. 3, only one orientation is shown for clarity. All heavy atoms were refined anisotropically,
H-atoms were fixed isotropically with atomic positions based on stereochemical considerations. Final R(F) ˆ
0.0602, wR(F2) ˆ 0.1681 for 511 parameters and 3228 reflections with I > 2s(I) and 3.52 < q < 49.988. CCDC-
214733.
X-Ray Crystal Structure of 11. Crystal data at 295 K for C23H26BF2N3O2 (Mr 425.28): triclinic, space group
3
≈
P1 (No. 2), Dc ˆ 1.042 g/cm , Z ˆ 6, a ˆ 13.9886(4), b ˆ 17.0634(5), c ˆ 18.9111(6) ä, a ˆ 71.360(2)8, b ˆ
72.540(2)8, g ˆ 88.770(2)8, Vˆ 4066.3(2) ä3; Bruker-Nonius Kappa-CCD diffractometer, MoKa radiation,
l ˆ 0.7107 ä. A dark-red crystal (linear dimensions ca. 0.3  0.3  0.02 mm) was obtained by slow evaporation
of a CHCl3 soln. The structure was solved by direct methods (SIR97) [27] and refined by full-matrix least-

Helvetica Chimica Acta Vol. 86 (2003)
3669
squares analysis (SHELXL-97) [28], by using an isotropic extinction correction and w ˆ 1/[s2(F2o ) ‡
(0.1974P)2 ‡ 1.6862P], where P ˆ (Fo2 ‡ 2Fc2 )/3. All heavy atoms were refined anisotropically (H-atoms
isotropically, whereby H-positions are based on stereochemical considerations). Final R(F) ˆ 0.087,
wR(F2) ˆ 0.258 for 839 parameters and 4959 reflections with I > 2s (I) and 3.13 < q < 20.038 (corresponding
R values based on all 7142 reflections are 0.118 and 0.298 resp.). CCDC-214739.
X-Ray Crystal Structure of 19. Crystal data at 253K for C 76H72N8O24 ¥ 2 Me2CO (Mr 1597.57): monoclinic,
space group P21/m (No. 11), Dc ˆ 1.234 g/cm3, Z ˆ 2, a ˆ 12.3125(3), b ˆ 27.0211(7), c ˆ 13.1175(4) ä, b ˆ
99.780(1)8, Vˆ 4300.7(2) ä3; Bruker-Nonius Kappa-CCD diffractometer, MoKa radiation, l ˆ 0.7107 ä. An
orange crystal, obtained by evaporation of a Me2CO soln. (linear dimensions ca. 0.3 Â 0.3 Â 0.28 mm) was
mounted at low temp. in epoxy resin to prevent evaporation of enclosed solvent. The crystals shatter below ca.
230 K. At 253 K, they desintegrate within a few hours. The structure was solved by direct methods (SIR97) [27]
and refined by full-matrix least-squares analysis (SHELXL-97) [28], by using an isotropic extinction correction
and w ˆ 1/[s2(F2o ) ‡ (0.1188P)2 ‡ 2.8782P], where P ˆ (Fo2 ‡ 2F2c )/3. All heavy atoms were refined anisotropi-
cally (H-atoms isotropically, whereby H-positions are based on stereochemical considerations). Final R(F) ˆ
0.081, wR(F2) ˆ 0.209 for 568 parameters and 4932 reflections with I > 2s (I) and 1.75 < q < 24.118
(corresponding R values based on all 6523reflections are 0.104 and 0.231 resp.). CCDC-214740.
X-Ray Crystal Structure of 24. Crystal data at 293K for C 80H64N8O16 ¥ MeCN (Mr 1434.46): monoclinic,
space group P2(1)/c (No. 14), Dc ˆ 1.311 g/cm3, Z ˆ 4, a ˆ 21.08(2), b ˆ 17.07(2), c ˆ 20.99(3) ä, b ˆ 104.03(9)8,
Vˆ 7332(15) ä3; Picker-Stoe diffractometer, CuKa radiation, l ˆ 1.5418 ä. Prismatic crystals (linear dimensions
ca. 0.1 Â 0.1 Â 0.07 mm) were obtained by slow evaporation from MeCN/CHCl3. The structure was solved by
direct methods (SHELXS-86) [29] and refined by full-matrix least-squares analysis (SHELXL-93) [30]. All
heavy atoms were refined anisotropically, H-atoms fixed isotropically with atomic positions based on
stereochemical considerations. Final R(F) ˆ 0.1088, wR(F 2) ˆ 0.2957 for 977 parameters and 3500 reflections
with I > 2s (I) and 2.16 < q < 42.508. CCDC-214734.
Crystallographic data (excluding structure factors) for the structures reported in this paper have been
deposited with the Cambridge Crystallographic Data Centre (CCDC). Copies of the data can be obtained, free
of charge, on application to the CCDC, 12 Union Road, Cambridge CB2 1EZ, UK (fax: ‡ 44(1223)336033; e-
mail: deposit@ccdc.cam.ac.uk).
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Received July 21, 2003