A novel approach to conformationally strained 2,2′-bipyridine thiacrown ethers and their chiral sulfoxides by sequential homo-coupling/DA-rDA reaction of 5,5′-bi-1,2,4-triazine-containing thiamacrocycles

Article abstract of DOI:10.1016/j.tet.2011.02.081

The synthesis of conformationally strained 2,2′-bipyridine thiamacrocycles 5, 6, 9, 10 and their chiral sulfoxides 11-14 is elaborated using, (1) homo-coupling of 1,2,4-triazine sulfide 3 with potassium cyanide and (2) Diels-Alder/retro Diels-Alder (DA-rDA) with 2,5-norbornadiene or 1-pyrrolidino-1-cyclopentene as the key steps. The crystal structure determinations of 4-6 and the theoretical calculations at DFT/B3LYP/6-311 ^G level were conducted thus establishing conformational preferences of the target thiamacrocycles

Full text of DOI:10.1016/j.tet.2011.02.081

Tetrahedron 67 (2011) 3098e3104
Contents lists available at ScienceDirect
Tetrahedron
journal homepage: www.elsevier.com/locate/tet
0
A novel approach to conformationally strained 2,2 -bipyridine thiacrown ethers
and their chiral sulfoxides by sequential homo-coupling/DAerDA reaction of
0
5
,5 -bi-1,2,4-triazine-containing thiamacrocycles
*
ꢀ
Justyna qawecka, Zbigniew Karczmarzyk , Ewa Wolinska, Ewa Olender, Danuta Branowska,
Andrzej Rykowski
*
Siedlce University, Department of Chemistry, 08-110 Siedlce, Poland
a r t i c l e i n f o
a b s t r a c t
0
Article history:
The synthesis of conformationally strained 2,2 -bipyridine thiamacrocycles 5, 6, 9, 10 and their chiral
sulfoxides 11e14 is elaborated using, (1) homo-coupling of 1,2,4-triazine sulfide 3 with potassium cya-
nide and (2) DielseAlder/retro DielseAlder (DAerDA) with 2,5-norbornadiene or 1-pyrrolidino-1-cy-
clopentene as the key steps. The crystal structure determinations of 4e6 and the theoretical calculations
at DFT/B3LYP/6-311G** level were conducted thus establishing conformational preferences of the target
thiamacrocycles.
Received 7 September 2010
Received in revised form 8 February 2011
Accepted 28 February 2011
Available online 5 March 2011
Keywords:
Ó 2011 Elsevier Ltd. All rights reserved.
0
2
,2 -Bipyridine base thiamacrocycles
Bi-1,2,4-triazine
DielseAlder reaction
X-ray analysis
DFT calculations
1
. Introduction
length of glycolate chain, is thermal oligomerization of poly-
9
0
ethylene glycols and failure in nucleophilic displacement of 6,6 -
0
0
The synthesis and properties of 2,2 -bipyridine (bpy) based
macrocycles has attracted a considerable attention of chemists for
many years owing to their applications in a wide range of fields.
disubstituted-2,2 -bipyridines by the diethylene glycol under the
7
reaction conditions. This last result may be due to the high ring
strain of the cyclization product. In most macrocycle synthesis the
1
10
They have been the subject of numerous studies in areas, such as
ring closing reactions are usually performed at a late stage of the
synthetic route. Such intramolecular macrocyclization has been
applied recently for the preparation of expanded crown ether based
2
3
4
11
supramolecular chemistry, catalysis, electrochemistry, photo-
chemistry,5 and molecular recognition. Consequently, new and
efficient methods for the preparation of bpy containing macro-
cycles with an appropriate ring size and predictable function re-
6
macrocycles using copper(I)-catalyzed azideealkyne cycloaddi-
12
tion. This reaction, which exemplifies the click chemistry phi-
13
main an attractive challenge in organic chemistry, particularly in
losophy, has been performed on tailor-made linear precursors
leading to a range of novel macrocycles. Utilizing this concept we
have elaborated a new and efficient route for preparing bihetero-
cycle-containing thiacrown ethers, starting from the corresponding
ethylene glycol oligomers bearing 1,2,4-triazine sulfides tethered to
0
the synthesis of C
2
-symmetric 2,2 -bipyridine-containing crown
ethers that have been developed recently for the enantiomeric
recognition of amino acids derivatives and chiral organic ammo-
6
c
0
nium salts. The most common synthesis of 2,2 -bipyridine based
7
8
14
crown and thiacrown ethers involves the direct nucleophilic
poly(ethylene glycol) chains as end groups. The construction of
0
0
displacement of 6,6 -bifunctional-2,2 -bipyridines by the dianions
of oligomeric glycolates or thioglycolates. The procedure afforded
variable 3e21% yields of desired 1:1 crown or thiacrown macro-
cycles accompanied by a large amount of noncyclic compounds and
16-, 19- and 22-membered bpy thiacrown ethers involved se-
quential homo-coupling of these 1,2,4-triazine sulfides by potas-
sium cyanide-catalyzed intramolecular cyclization and the inverse
electron demand DielseAlder/retro DielseAlder (DAerDA) reaction
7
15
larger oligomers. One drawback of this strategy, depending on the
of resulting bi-1,2,4-triazine-containing thiamacrocycles. From
14
our preliminary findings and theoretical calculations one may
assume that the approach is also suitable for the rings of 13 or less
members. Here we report a full report on application of this ap-
proach to the synthesis of such conformationally strained
*
Corresponding authors. Tel.: þ48 25 6431093; fax: þ48 25 6442095; e-mail
address: rykowski@ap.siedlce.pl (A. Rykowski).
0
040-4020/$ e see front matter Ó 2011 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2011.02.081

J. Ławecka et al. / Tetrahedron 67 (2011) 3098e3104
3099
thiamacrocycles 5, 6, and 9, 10 (Schemes 3 and 4) and their chiral
sulfoxides 11e14 (Scheme 5). The crystal structures determinations
and the theoretical calculations at DFT/B3LYP/6-311G** level were
conducted thus establishing conformational preferences of the
target compounds.
a cation 3a as a result of template reaction which proceeds between
its coordination sites and an alkaline metal ion (Scheme 2). The 1,2,4-
triazine-acceptor and 1,2,4-triazine-donor end groups in cation 3a
can recognize each other and get close enough, thus increasing the
rate of the cyclization step.
N
NC
N
2
. Results and discussion
N
N
KCN
N
N
3
K
The first step of the synthetic protocol presented in Scheme 1,
S
S
O
required an easily access to an appropriate 1,2,4-triazine bis-sulfide 3.
3a
Br
Br
H3N NH
Br
HN NH3
Scheme 2. Formation of the cyclization intermediate.
thiosemicarbazide
EtOH, reflux
O
S
O
S
HN
NH
2
The preparation of bpy thiacrown ethers 5, 6, could involve the
double DAerDA reaction of 4 with an electron-rich dienophile or
Br
1
4
0% glyoxal
NaHCO3
H2O
15
reactive strained olefine. To establish optimal conditions for the
cycloaddition, the reaction of its analog 8 without oxygen in the
tether with 1-pyrrolidino-1-cyclopentene was investigated first.
Earlier, we have reported that DAerDA reactions of 5,5 -bi-1,2,4-
14
0
N
N
N
N
N
triazines with 1-pyrrolidino-1-cyclopentene without solvent at
N
N
S
N
KCN
H O
ꢀ
0
16
N
N
N
N
150 C led to bis-annulated 2,2 -bipyridines exclusively. The re-
S
S
action of 8 with 1-pyrrolidino-1-cyclopentene was carried out
under the same reaction conditions for 17 h to afford cyclopenteno
c]2,2 -bipyridine based cyclophane 9 in 57% yield (Scheme 3).
O
2
O
S
0
[
4
3
Scheme 1. Synthesis of 1,2,4-triazine bis-sulfide 3 and thiamacrocycle 4.
N
N
N
N
N
N
S
S
The synthesis of 3 was prepared via a two-step one-pot pro-
cedure, which involved S-alkylation of thiosemicarbazide with
8
0
.5 equiv of diethylene glycol dibromide 1 to give the intermediary
N
N
diquaternary salt 2, followed by the condensation of the latter with
p-cymene
40 °C
reflux
1
4
0% glyoxal in the presence of sodium bicarbonate. With bis-sulfide
3
in hand we next evaluated its intramolecular homo-coupling re-
0
action leading to 5,5 -bi-1,2,4-triazine thiamacrocycle 4 by using
potassium cyanide. According to our previous report the process was
carried out in water at room temperature under relatively high di-
lution conditions to avoid unwanted intermolecular side reactions,
prior to the desired cyclization step. The reaction was completed
within 15 min giving thiamacrocycle 4 exclusively (monitored by
TLC). After the reaction, pure product could be easily recovered in
good yield by extraction with dichloromethane (see Table 1). The
efficiency of this purification procedure was confirmed by NMR and
HRMS spectra of the product. It seems likely that fast and efficient
formation of 4 may be attributed to a favorable conformation of the
linear precursor 3 resulting in low activation energy and favorable
entropy for cyclization. On the basis of our previous studies14 we
assume that potassium cyanide-catalyzed cyclization occurs via
a primary cyanide addition to C(5) of 1,2,4-triazine ring leading to
N
N
N
S
S
S
S
9
10
Scheme 3. Synthesis of cyclophanes 9 and 10.
Also the reaction of 4 with the same enamine showed the
generality of this process, since conformationally strained thia-
crown ether 5 with cyclopenteno[c]2,2 -bipyridine unit in the cyclic
backbone was obtained as the sole product in 64% yield. The for-
mation of uncondensed, double bpy thiacrown ether 6 was initially
attempted via the DAerDA reaction of 4 with 2,5-norbornadiene in
boiling p-cymene. Under these conditions the expected thiacrown
ether 6 was obtained in 38% yield together with some amount of
monoadduct 7 (Scheme 4). The structure of 7 is based on its NMR
0
Table 1
Yields of compounds 3e7 and 9e14
4
Compound
Yield %
N
3
4
5
38
73
64
63
12
57
60
63
46
36
35
p-cymene
1
40 °C
a
6
N
7
9
N
0a
1
2
3
4
N
N
O
1
1
1
1
1
N
N
N
N
S
S
S
O
S
O
S
S
a
Scheme 4. Synthesis of macrocycles 5e7.
In sealed Carius tube.

3100
J. Ławecka et al. / Tetrahedron 67 (2011) 3098e3104
and ms spectra clearly showing the chemical shifts and multiplicity
pattern characteristic for pyridine and 1,2,4-triazine rings (see
Experimental). When the above reaction was followed by TLC, it
was evident that intermediate 7 was slowly converted into 6 during
extended heating. However, when 4 was reacted with 2,5-norbor-
nadiene in a sealed Carius tube at an elevated temperature under
higher pressure, the only product was the corresponding diadduct
6
, obtained in good yield (see Table 1). Compound 8 also reacts
efficiently with 2,5-norbornadiene under the conditions men-
tioned above giving directly compound 10 in 60% yield (Scheme 3).
Finely, we have evaluated the asymmetric sulfoxidation of
compounds 5, 6, and 9, 10 using chiral oxaziridine developed by
17
Davis. The reactions were performed in methylene chloride at
room temperature (Scheme 5).
Davis oxaziridine
N
N
N
N
CH2Cl2
S
X
O
S
S
X
S
Fig. 2. A view of the X-ray molecular structures of two independent molecules AB and
CD of 4 with the atomic labeling.
5
, 6 X = O
11 X = O (63%, ee 9%)
12 X = O (46%, ee 11%)
9
, 10 X = CH2
1
3 X = CH2 (36%, ee 2%)
4 X = CH2 (35%, ee 19%)
1
eC2BeN2B about the central bond of the bipyridyl system of ꢁ11.7
ꢀ
0
ꢀ
(
5
3) for 5 and ꢁ19.67(18) for 6. In the molecules AB and CD of 4 the
Scheme 5. Asymmetric sulfoxidation of cyclophanes 5, 6 and 9, 10.
,5 -bi-1,2,4-triazine system adopts also cis (syn) conformation
with
the
torsion
angle
N4AeC5AeC5BeN4B
and
ꢀ
N4CeC5CeC5DeN4D of 2.5(3) and 19.1(3) , respectively. The cis
conformation of the bi-heterocyclic systems in 4e6 is forced by the
strain effect in the nine-membered thiaethereal chain during the
cyclization process. The problem of the change of conformation of
bi-heterocyclic system from cis to trans conformation depending
on the length of thiaethereal chain was discussed by us earlier for
Under these conditions the monosulfoxides 11e14 could be
obtained in reasonable or good yield (see Table 1). The preliminary
use of these monosulfoxides as chiral auxiliary was tested in
asymmetric addition of the diethylzinc to benzaldehyde, however
their catalytic efficiency was poor and the ee values (3e7%) of the
chiral alcohol 15 (Fig. 1) thus obtained were much lower than the
0
14
18
2,2 -bipyridine thiamacrocyles.
values observed for other catalysts.
In molecules 5 and 6 and molecule CD of 4 the bond lengths and
19
angles are in normal ranges and they are very similar to those
0
HO
C
2
H
5
found in previously reported related structures of annulated 2,2 -
14
bipyridine thiamacrocycles. The statistically significant differ-
ences in the bond lengths and angles appear in the thiaethereal
bridge in molecule AB of 4 mainly due to positional disorder of C11
2
and C12 atoms and their large thermal motions. The C symmetry of
15
the macrocycles 4e6 is not retained in their crystals because the
molecules occupy an asymmetric position in the unit cell. However,
the torsion angles around following bonds of thiaethereal chains in
Fig. 1. 1-Phenyl-1-propanol.
5
and 6 (Table 1 in Supplementary data) show practically the same
cis-gauche-trans-gauche conformation of the symmetry related left
A) in 5 and 6 and (C) in 4 and right (B) in 5 and 6 and (D) in 4 parts
The spectroscopic properties of the bpycyclophanes 5, 6 and 9,10
are entirely consistent with the functional group present. The pre-
ferred conformations of these macrocycles are determined by ana-
lyzing the chemical shifts of 3-pyridyl hydrogens and X-ray
analysis. The resonances of such hydrogens in compounds 5, 6 and 9,
(
7
of molecules. The split of C11 and C12 atoms into two sites in
molecule AB of 4 gives four different conformations of its thiae-
thereal chain indicated as AEeBG, AEeBH, AFeBG, and AFeBH.
10 (range from 7.15 to 7.35 ppm) indicate cis arrangement for these
These conformations are also cis-gauche-trans-gauche for (A) and
biheterocycles. This is consistent with the chemical shifts of pyridine
protons (7.36e7.47 ppm) in the annulated 16- and 19-membered
bpy thiacrown ethers having cis conformation. In contrast, the
chemical shifts of bipyridine protons in 22-membered thiacrown
0
(B) parts differing in C11eC12eO1eC12 torsion angle (two pairs
AEeBG, AFeBH, and AEeBH, AFeBG) and signs of respective torsion
angles (Table 2 in Supplementary data). The theoretical calculation
on DFT/B3LYP/6-311þþG(d,p) level showed that the analyzed
conformations of the molecules 4e6 obtained after energy mini-
mization and geometry optimization do not differ significantly
from those observed in crystalline state and the pairs of confor-
mations AEeBG, AFeBH, and AEeBH, AFeBG of molecule 4 are
equi-energetically (EAEeBG¼EAFeBH¼ꢁ1587.34188 and EAEeBH¼EAFe
14
ether (7.85 ppm) show trans conformation exclusively. These data
0
also prove that 13-membered macrocyclic system 4 containing 5,5 -
bi-1,2,4-triazine skeleton also exist in cis conformation.
In order to establish the conformational preferences of the title
thiamacrocycles in the crystalline state the crystal structure de-
terminations of 4e6 were undertaken. The X-ray structure analysis
of 4 revealed, that the asymmetric part of the unit cell of its crystal
contains two independent molecules AB and CD (Fig. 2). The
structures of the molecules 5 and 6 are shown in Fig. 3. One can see
BG
them of
¼
ꢁ1587.34463 a.u.) with small difference of energy between
D
E¼1.73 kcal/mol. The conformations of molecules 4e6 in
the crystals are stabilized by the pairs of short intramolecular
contacts C12AeH/N1A and C12BeH/N1B in 5 and 6, C12C/N4C
and C12DeH/N4D in molecule CD and C12GeH/N4B in molecule
0
that the molecules 5 and 6 containing, respectively, annulated 2,2 -
0
bipyridine and 2,2 -bipyridine ring systems exist in the crystal in
ꢁ
AB of 4 with H/N distances in the range from 2.50 to 2.60 A.
the cis (syn) conformation with the torsion angle N1AeC2A

J. Ławecka et al. / Tetrahedron 67 (2011) 3098e3104
3101
Fig. 3. A view of the X-ray molecular structures of 5 and 6 with the atomic labeling.
0
The analysis of the cyclic molecules obtained from 2,2 -bipyridyl
3. Conclusions
and polyoxyethylene oligomers (x-mers) showed that the cycliza-
tion is impossible for x¼2, barely possible for x¼3, and most readily
We have demonstrated a facile approach to conformationally
10
0
achieved with x¼5e7. However, replacement of the O atoms with
the S atoms in the linkages of the ethereal chain to the pyridine and
triazine rings in 4e6 makes the cyclization possible for x¼2. As-
suming the bond lengths CareO¼1.370(11), Csp3eO¼1.431(13),
strained 2,2 -bipyridine based thiamacrocycles by sequential
0
homo-coupling/DAerDA reaction of resulting 5,5 -bi-triazine thia-
macrocycles. The method should be of general use for the synthesis
of related macrocycles and analogs.
ꢁ
19
C
areS¼1.773(9) and Csp3eS¼1.817(13) A the implementation of
the S atom in the place of O atom extends the thiaethereal (4e6)
and thiaalkyl (8e10) chains for 1.578 A in comparison with analo-
4
4
. Experimental section
.1. General methods
ꢁ
gous ethereal chains. Theoretical calculations on DFT/B3LYP/6-
3
11þþG(d,p) level predict that in the case of thiaalkyl chain the
cyclization is also possible for four CH
2
groups. The structure of
Melting points are uncorrected. H and 13C NMR spectra were
determined at 200 and 50 MHz, respectively, with a Varian Gemini
spectrometer. Chemical shifts ( ) are given in parts per million from
tetramethylsilane with the solvent resonance as the internal stan-
dard (CDCl
¼7.26). Coupling constants are given as absolute
1
0
modeled appropriate 5,5 -bi-1,2,4-triazine macrocycle with rea-
sonable geometry and conformation obtained after geometrical
parameters optimization and energy minimization is shown in
d
0
Fig. 4. The 5,5 -bi-1,2,4-triazine system adopts cis conformation
3
, d
0
0
ꢀ
with the torsion angle NeCeC eN of 28.4 . The bond lengths and
angles have acceptable values. The only small constrains within the
biheterocycle system appearing with deformation of exocyclic
valency angles at C5 and C5 atoms (127.4 and 113.2 ) are observed.
The experimental trials of synthesis this compound are in progress.
values expressed in Hertz. Mass spectra were obtained by using
AMD 604 (AMD Intectra GmbH, Germany) and GC/MS QP 5050
Shimadzu (30 mꢂ0.25 mm ID-BPX 5 0.25 mm) spectrometers. El-
emental analyses were recorded with a PerkineElmer 2400-CHN
analyzer and the results for indicated elements were within 0.3% of
the calculated values. Optical rotation values were measured at
room temperature with a JASCO P-2000 polarimeter. The ee values
were determined by HPLC analysis by using a chiral stationary
phase column (Chirobiotic T or Chiralpac AS). Thin layer chroma-
tography (TLC) was carried out on aluminum sheets percolated
with silica gel 60 F254 (Merck). Column chromatography separa-
tions were performed by using Merck Kieselgel 60
0
ꢀ
(
0.040e0.060 mm). Solvents were dried and distilled according to
0
0
standard procedures. Synthesis of 1,7-dithia[7]3,3 -5,5 -bis(1,2,4-
triazine)cyclophane (8) was performed according to our published
14
procedure.
4.2. Procedure for the preparation of 1,5-bis(1,2,4-triazin-3-
ylsulfanyl)-3-oxapentane (3)
A solution of thiosemicarbazide (5.9 g, 14.28 mmol) and 1-
bromo-2-(2-bromoethoxy)ethane (1) (1.68 g, 7.28 mmol) in abso-
lute ethanol (40 mL) was stirred at reflux until thiosemicarbazide
was consumed (TLC control). The ethanol was then evaporated and
a solution of glyoxal (2.1 mL, 40% solution in water, 14.28 mmol)
and sodium bicarbonate (1.2 g, 14.28 mmol) in ice water (40 mL)
was added to the brown residue containing hydrobromide salt 2.
After stirring at room temperature for 30 min, methanol (55 mL)
0
Fig. 4. The structure of 5,5 -bi-1,2,4-triazine thiamacrocyle with four CH
2
groups in
thiaalkyl chain obtained after theoretical calculation on DFT/B3LYP/6-311þþG(d,p)
level.

3102
J. Ławecka et al. / Tetrahedron 67 (2011) 3098e3104
was added and the mixture was stirred at room temperature for
4 h. Methanol was evaporated at vacuo and the water layer was
extracted with CH Cl
(5ꢂ10 mL). After evaporation of the solvent
from the combined extracts, the remaining residue was purified by
mixture was separated by column chromatography (CH
tone, 20:1) to give compounds 6 (0.07 g, 38%), followed by CH
acetone (10:1) to afford monoadduct 7 (0.02 g, 12%). Compound 10
was isolated as the only product (0.10 g, 60%).
2
C
2
/ace-
Cl
2
2
2
/
2
2
column chromatography (CH
2
Cl
2
/acetone, 10:1) to give pure com-
Method B. A solution of norbornadiene (1.8 mL) in p-cymene
(4 mL) was added to a Carius tube containing 4 (0.173 g,
0.59 mmol). The tube was tightly closed and the mixture was
ꢀ
pound 3 as white solid (0.84 g, 38%); mp 56e58 C; R
f
(CH
)¼321 (3.43);
), 3.80 (4H, t, J¼6.4 Hz,
), 8.36 (2H, d, J¼2.4 Hz, triazine hydrogen atoms), 8.91 (2H, d,
(50 MHz, CDCl ) 30.1 (SCH ),
), 145.4, 148.1, 173.7 triazine carbon atoms; HRMS (EI):
OS requires 296.0514.
2 2
Cl /ac-
etone, 10:1) 0.42; UV/vis (CHCl
200 MHz, CDCl
) 3.44 (4H, t, J¼6.4 Hz, SCH
OCH
3
, nm):
lmax (log
3
d
H
ꢀ
(
3
2
heated for 86 h at 140 C. The solvent was evaporated in vacuo and
2
the product was purified by column chromatography (CH
tone, 20:1) to give pure compound 6 (0.11 g, 63%).
2 2
Cl /ace-
J¼2.4 Hz, triazine hydrogen atoms);
d
C
3
2
6
9.0 (OCH
2
þ
0
0
M , found 296.0509. C10
H
12
N
6
2
4.5.1. 4-Oxa-1,7-dithia[7](6,6 )-2,2 -bis(pyridine)cyclophane (6). Mp
ꢀ
1
32e133 C; R
f
(CH
max (log
3.29e3.37 (4H, m, SCH
2
Cl
2
/acetone, 100:1) 0.55; UV/vis (CHCl
)¼327 (4.03); (200 MHz, CDCl
), 4.05e4.14 (4H, OCH ), 7.17 (2H, d,
3
): UV/vis
0
0
4
.3. Synthesis of 4-oxa-1,7-dithia[7](3,3) -5,5 -bis(1,2,4-
(CHCl
3
,
nm):
l
3
d
H
3
)
triazine)cyclophane (4)
2
2
J¼8.0 Hz, pyridine hydrogen atoms), 7.46 (2H, d, J¼8.0 Hz, pyridine
A suspension of compound 3 (0.175 g, 0.59 mmol) in water
134 mL) was stirred at 40 C until complete dissolution. After
hydrogen atoms), 7.57 (2H, t, J¼7.6 Hz, pyridine hydrogen atoms);
ꢀ
(
d
C
(50 MHz, CDCl
3
) 27.9 (SCH
2
), 66.2 (OCH
2
), 116.2, 121.5, 136.5,
OS : C,
cooling to room temperature, potassium cyanide (0.137 g,
.12 mmol) was added as a solid, and the resulting mixture was
stirred for 15 min. The mixture was extracted with CH Cl
5ꢂ50 mL). The combined extracts were dried over MgSO , filtered,
and concentrated in vacuo. The crude product was purified by
155.2, 158.5 pyridine carbon atoms; Anal. Calcd for C14
H
14
N
2
2
2
57.93; H, 4.83; N, 9.66%. Found: C, 57.89; H, 4.83; N, 9.62.
2
2
(
4
4.5.2. 10-Oxa-7,13-dithia-4,5,18,19-tetraaza-tricyclo[12.3.1.12,6]non-
adeca-1(18),2,4,6(19),14,16-hexaene
(7). (0.02 g,
12%);
mp
, nm):
ꢀ
column chromatography (CH
pound 4 (0.127 g, 73%) as a yellow solid (mp 210e211 C); R
2
Cl
2
/acetone, 10:1) to give pure com-
236e237 C; R
f
(CH
)¼357 (3.70);
), 4.02e4.15 (4H, m, CH
pyridine hydrogen atom), 7.61e7.69 (2H, m, pyridine hydrogen
atoms), 9.41 (1H, s, triazine hydrogen atom); (50 MHz, CDCl
28.6 (SCH ), 29.1 (SCH ), 65.4 (OCH ), 65.8 (OCH ), 117.9, 124.4,
2
Cl
2
/acetone, 100:1) 0.19; UV/vis (CHCl
(200 MHz, CDCl
), 7.34 (1H, dd, J¼1.8 Hz, J¼7.0 Hz,
3
ꢀ
f
lmax (log
3
d
H
3
) 3.25e3.33 (4H, m,
(
(
CH
3.38);
2
Cl
2
d
/acetone, 10:1) 0.39; UV/vis (CHCl
(200 MHz, CDCl
) 3.30 (4H, t, J¼6.4 Hz, SCH
), 9.55 (2H, s, triazine H); (50 MHz, CDCl
), 145.3, 148.1, 173.7 triazine carbon atoms;
OS requires 294.0357.
3
, nm):
l
max (log
), 4.06 (4H, t,
) 30.0
3
)¼375
CH
2
2
H
3
2
J¼6.4 Hz, OCH
2
d
C
3
d
C
3
)
(
SCH
2
), 68.9 (OCH
2
2
2
2
2
þ
HRMS (EI): M , found 294.0348. C10
10
H N
6
2
136.8, 141.6, 150.1 pyridine carbon atoms, 153.0, 160.9, 174.4 triazine
þ
carbon atoms; HRMS (EI): M , found 292.0464. C12
quires 292.0452.
12 4 2
H N OS re-
4
.4. General procedure for the preparation of cyclophanes 5
and 9
0
0
ꢀ
4
.5.3. 1,7-Dithia[7](6,6 )-2,2 -bis(pyridine)cyclophane
(10). Yield
Cyclophane 4 or 8 (2.96 mmol) was added to freshly distilled
-pyrrolidine-1-cyclopentene (2.43 g, 17.75 mmol). The mixture
(0.10 g, 60%), mp 151e152 C; R
f
(CH
)¼330 (4.01);
), 1.99e2.19 (4H, m, CH
), 7.18 (2H, d, J¼7.8 Hz, pyridine hydrogen atoms), 7.43 (2H, d,
J¼7.3 Hz, pyridine hydrogen atoms), 7.56 (2H, t, J¼7.6 Hz, pyridine
hydrogen atoms); (50 MHz, CDCl ) 27.6 (CH ), 28.7 (CH ), 29.9
(SCH ), 116.0, 121.4, 136.2, 155.2, 159.1 pyridine carbon atoms. Anal.
Calcd for C15 : C, 62.50; H, 5.56; N, 9.72%. Found: C, 62.43; H,
5.56; N, 9.71.
2
Cl
2
/acetone, 100:1) 0.92; UV/
(200 MHz, CDCl
), 3.14e3.23 (4H, m,
1
vis (CHCl
1.59e1.73 (2H, m, CH
CH
3
, nm):
l
max (log
3
d
H
3
)
ꢀ
was heated at 150 C for 17 h, and then evaporated in vacuo. The
residue was purified by column chromatography (CH Cl /acetone,
2
2
2
2
2
5
0:1) to give pure compounds 5 or 9.
d
C
3
2
2
0
0
4.4.1. 4-Oxa-1,7-dithia[7](6,6 )-2,2 -bis(cyclopenta[c]pyridine)cyclo-
2
ꢀ
phane (5). (0.70 g, 64%) as a yellow solid; mp 269e270 C; R
f
16 2 2
H N S
(
CH
2
Cl
2
/acetone, 50:1) 0.59; UV/vis (CHCl
(200 MHz, CDCl
) 2.15 (4H, J¼7.4 Hz, CH
), 2.95 (4H, J¼7.6 Hz, CH ), 3.29e3.38 (4H, m, SCH
.06e4.14 (4H, m, OCH ), 7.37 (2H, s, pyridine hydrogen atoms);
50 MHz, CDCl ) 24.3 (CH ), 27.4 (CH ), 29.5 (CH ), 32.8 (SCH
3
, nm):
l
max (log
3
)¼319
(
4.04);
d
H
3
2
), 2.80 (4H,
J¼7.4 Hz, CH
2
2
2
d
),
4.6. General procedure for the preparation of sulfoxides 11,
12, 13, and 14 (Davis method)
4
(
2
C
),
3
2
2
2
2
6
6.3 (OCH
2
), 112.8, 136.1, 153.2, 153.6, 154.1 pyridine carbon
To a solution of sulfide 5, 6, 9 or 10 (1 mmol) in anhydrous
þ
0
atoms; HRMS (EI): M , found 370.1183. C20
22
H N
2
OS
2
requires
methylene chloride (30 mL), was added (þ)-(8,8 -dichlor-
370.1173.
ocamphorylsulfonyl)oxaziridine (0.75 mmol) and the reaction
mixture was stirred at room temperature for 24 h. Afterward, the
solvent was evaporated, and the residue was purified by flash
0
0
4
.4.2. 1,7-Dithia[7](6,6 )-2,2 -bis(cyclopenta[c]pyridine)cyclophane
ꢀ
(9). (0.62 g, 57%); mp 191e192 C; R
f
(CH
2
Cl
2
/acetone, 100:1) 0.62;
), 1.99e2.21 (8H, m,
), 2.89e2.97 (4H, m, CH ), 3.14e3.22
), 7.32 (2H, s, pyridine hydrogen atoms); (50 MHz,
) 24.4 (CH ), 27.8 (CH ), 28.9 (CH ), 29.5 (CH ), 29.7 (CH ),
2 2
chromatography (CH Cl /acetone, 10:1.5) to yield pure monosulf-
oxides 11e14.
d
H
(200 MHz, CDCl
), 2.76e2.83 (4H, m, CH
3H, m, CH
CDCl
2.9 (SCH
3
) 1.50e1.59 (3H, m, CH
2
CH
(
2
2
2
0 0
4.6.1. 4-Oxa-1,7-dithia[7](6,6 )-2,2 -bis(cyclopenta[c]pyridine)cyclo-
2
d
C
2
0
3
2
2
2
2
2
phane sulfoxide (11). Yield (0.24 g, 63%), oil, ee 9%, [
CH Cl ); R (CH Cl /adetone, 10:1) 0.22; IR (KBr): 1032 cm (S]
O); UV/vis (CHCl , nm): max (log (200 MHz,
a
]
D
ꢁ8.1 (c 0.7,
ꢁ
1
3
2
), 112.77, 135.9, 153.4, 153.8 pyridine carbon atoms;
2
2
f
2
2
n
þ
HRMS (EI): M , found 368.1369. C21
H N
24 2
S
2
requires 368.1381.
3
l
3
)¼315 (3.91);
d
H
CDCl3) 2.10e2.40 (4H, m), 2.78e2.82 (2H, m), 2.93e3.06 (4H, m),
3.11e3.62 (6H, m), 3.92e4.09 (4H, m), 7.42 (1H, s, pyridine hydro-
4
.5. General procedure for the preparation of cyclophanes 6,
7
, and 10
gen atom), 7.72 (1H, m, pyridine hydrogen atom);
CDCl ) 24.3 (CH ), 25.0 (CH ), 27.6 (CH ), 29.6 (CH ), 32.5 (CH
32.9 (SCH ), 47.6 (CH SO), 61.5, 66.6 (OCH ), 113.2, 118.4, 137.0,
d
C
(50 MHz,
3
2
2
2
2
2
),
Method A. A solution of 2,5-norbornadiene (1.8 mL) in p-cymene
4 mL) containing compound 4 or 8 (0.59 mmol) was heated for
2
2
2
(
153.0, 154.0, 155.6, 158.2, 168.8, 179.3 pyridine carbon atoms; HRMS
ꢀ
þ
2
0 h at 140 C. The solvent was evaporated in vacuo and the
(EI): M , found 386.1114. C20
H
22
N
2
O
2
S
2
requires 386.1123. HPLC

J. Ławecka et al. / Tetrahedron 67 (2011) 3098e3104
3103
analysis (Chiralpac AS, hexane/(ether/2-propoanol 4:1) 60:30, flow
2
q
scans. Data collections for 4 and 6 were performed on the Bruker
ꢁ1
rate 0.5 mL min ): t
R
¼36.17 min (54.5%), 48.82 min (45.5%).
SMARTAPEX II CCD diffractometer; crystal sizes 0.18ꢂ0.14ꢂ0.09 mm
ꢁ
(
4) and 0.28ꢂ0.19ꢂ0.09 mm (6), Mo K
a
(l
¼0.71073 A) radiation,
u
20
0
0
4
.6.2. 4-Oxa-1,7-dithia[7](6,6 )-2,2 -bis(pyridine)cyclophane sulfox-
scans. All structures were solved by direct methodsusing SHELXS97
ꢀ
20
20
ide (12). Yield (0.14 g, 46%); 149e150 C, ee 11%, [
CH Cl ); R (CH Cl /acetone, 10:1) 0.17; IR (KBr):
O); UV/vis (CHCl , nm): max (log
)¼324 (3.84);
CDCl ) 3.12e3.21 (1H, m), 3.41e3.55 (2H, m), 3.80e3.97 (2H, m),
.12e4.36 (2H, m), 4.47e4.61 (1H, m), 7.17e7.29 (1H, m), 7.56e7.67
2H, m), 7.85e7.86 (1H, m), 7.89e8.09 (2H, m); (50 MHz, CDCl
), 116.3, 121.5, 121.6,
a
n
]
D
þ8.9 (c 0.64,
and refined by full-matrix least-squares with SHELXL97. The H
atoms were positioned geometrically and treated as riding on their
parent C atoms with CeH distances of 0.93 A (aromatic) and 0.97 A
(CH ). All H atoms were refined with isotropic displacement param-
eters taken as 1.5 times those of the respective parent atoms. All
ꢁ
1
2
2
f
2
2
1038 cm (S]
(200 MHz,
ꢁ
ꢁ
3
l
3
d
H
3
2
4
(
2
21
d
C
3
)
calculationswere performed using WINGXversion1.64.05package.
8.6 (SCH
2
), 52.5 (SOCH
2
), 62.6, 66.9 (OCH
2
CCDC 791625 (4), CCDC 791626 (5), CCDC 791627 (6) contain the
supplementary crystallographic data for this paper. These data can be
obtained free of charge at www.ccdc.cam.ac.uk/conts/retrieving.html
[or from the Cambridge Crystallographic Data Centre (CCDC), 12
Union Road, Cambridge CB2 1EZ, UK; fax: þ44(0) 1223 336 033;
email: deposit@ccdc.cam.ac.uk].
1
22.2, 136.8, 138.8, 153.8, 154.9, 159.5, 164.9 pyridine carbon atoms;
þ
HRMS (EI): M , found. 306.0492 C14
14 2 2 2
H N O S requires 306.0497.
HPLC analysis (Chirobiotic T, hexane/(ether/2-propoanol 4:1)
ꢁ1
6
0:40, flow rate 0.5 mL min ): t
R
¼21.98 min (44.4%), 24.70 min
(
55.5%).
0
0
4
.6.3. 1,7-Dithia[7](6,6 )-2,2 -bis(cyclopenta[c]pyridine)cyclophane
4.7.1. Crystal data of 4. C10
H
10
N
6
OS
2
, M¼294.36, monoclinic, space
ꢁ
ꢀ
20
D
sulfoxide (13). Yield (0.14 g, 36%); mp 190e191 C; ee 2%, [
þ10.0 (c 0.7, CH Cl ); R (CH Cl /acetone, 10:1) 0.33; IR (KBr):
020 cm (S]O); UV/vis (CHCl , nm): max (log
)¼313 (3.93);
200 MHz, CDCl ) 2.10e2.25 (9H, m, CH
), 2.78 (2H, t, J¼7.6 Hz,
CH ), 2.82e3.02 (5H, m, CH ), 3.10e3.50 (5H. m, CH ), 3.80e3.94
1H, m, CH ), 7.35 (1H, s, pyridine hydrogen atom), 7.65 (1H, s,
pyridine hydrogen atom);
), 27.7 (CH ), 29.4 (CH ), 29.6 (CH
), 50.27 (SOCH
54.0, 154.6, 155.5, 157.8 pyridine carbon atoms; HRMS (EI): M ,
a
]
group C2/c, a¼30.5580 (4), b¼10.0847 (2), c¼16.4199 (4) A,
ꢀ
ꢁ
3
ꢁ3
2
2
f
2
2
n
b
¼95.813 (1) , V¼1141.24 (7) A , Z¼16, dcalcd¼1.554 Mg m , F
ꢁ1
ꢁ1
1
(
3
l
3
d
H
(000)¼2432,
m
q
(Mo K
a
)¼0.424 mm , T¼293 K, 44,408 measured
ꢀ
3
2
reflections
(
range 2.13e25.76 ), 4829 unique reflections
2
2
2
(Rint¼0.033), final R¼0.035, wR¼0.091, S¼1.007 for 3786 reflections
(
2
with I>2 (I). The final residual electron-density maps showed that
s
d
C
(50 MHz, CDCl
3
) 19.3 (CH ), 24.3 (CH
2
), 29.7 (CH ), 32.5 (CH
2
2
2
),
),
the N1A, N2A and C6A atoms of 1,2,4-triazine ring and C11 and C12
atoms of thiaethereal chain are disordered over two sites. The oc-
cupancy factors (s. o. f.) for the split nitrogen and carbon atoms
were refined and finally fixed at 0.5.
2
3
1
5.0 (CH
2
2
2
2
2.9 (SCH
2
2
), 112.9, 118.3, 136.6, 140.9, 153.2, 153.6,
þ
found 384.13259. C21
24
H N
2
2
OS requires 384.133009. HPLC analysis
(
0
Chiralpac AS, hexane/(ether/2-propoanol 4:1) 60:30, flow rate
4.7.2. Crystal data of 5. C20
H
22
N
2
OS
2
, M¼350.52, triclinic, space
ꢁ
ꢁ1
.5 mL min ): t
R
¼30.25 min (51.0%), 37.65 min (49.0%).
group P1, a¼8.232 (1), b¼9.367 (1), c¼13.027 (2) A,
a
¼81.59 (1),
ꢀ
ꢁ
3
b
¼79.13
(1),
g
¼62.92
(1) ,
V¼876.2
(2)
A ,
Z¼2,
0
0
ꢁ3
ꢁ1
4
.6.4. 1,7-Dithia[7](6,6 )-2,2 -bis(pyridine)cyclophane sulfoxide (14).
d
calcd¼1.404 Mg
m
,
F(000)¼392,
m
(Cu
Ka
)¼2.831 mm
,
2
0
ꢀ
Yield (0.10 g, 35%), ee 19%, [
a
]
D
n
ꢁ8.34 (c 1.0, CH
2
Cl
1027 cm (S]O); UV/vis (CHCl
(200 MHz, CDCl ) 1.56e1.71 (3H,
), 2.18e2.40 (2H, m, CH ), 2.79e2.95
), 3.13e3.41 (2H, m, CH ), 3.64e3.78 (1H, m, CH ),
2
); R
f
(CH
2
Cl
2
/
,
T¼293 K, 3881 measured reflections (
q
range 3.46e80.25 ), 3460
ꢁ
1
acetone, 10:1) 0.26; IR (KBr):
nm): max (log
)¼324 (3.79);
m, CH ), 1.92e2.09 (1H, m, CH
1H, m, CH
3
unique reflections (Rint¼0.036), final R¼0.048, wR¼0.138, S¼1.092
l
3
d
H
3
for 2974 reflections with I>2 (I). The crystal of 5 used in X-ray
s
2
2
2
diffractometer measurement was non-merohedral twin. The
structure was easily solved by direct methods and all non-H atoms
(
2
2
2
7
.17e7.21 (1H, m, pyridine hydrogen atom), 7.43e7.68 (2H, m,
were found. However the refinement only converged to R of 0.27
2
pyridine hydrogen atoms), 7.80e7.84 (1H, m, pyridine hydrogen
and the refinement statistics showed that the K¼mean(F
o
)/mean
2
atom), 7.94e8.04 (2H, m, pyridine hydrogen atoms);
CDCl ) 21.1 (CH ), 27.4 (CH ), 27.7 (CH ), 30.5 (SCH ), 54.7 (SOCH
16.1, 121.3, 121.4, 122.1, 136.4, 138.5, 153.9, 155.2, 160.3, 165.1 pyr-
d
C
(50 MHz,
(F
Additionally, for all of the disagreeable reflections F
greater than F . The Laue symmetry 1 gives a respectably low value
c
) was systematically high for reflections with low intensity.
3
2
2
2
2
2
),
o
is much
1
c
þ
idine carbon atoms; HRMS (EI): M , found 304.0700. C15
requires 304.0704. HPLC analysis (Chirobiotic T, hexane/(ether/2-
propoanol 4:1) 15:20(60), flow rate 0.5 mL min ): t
H
16
N
2
OS
2
for R(merge) of 0.042 and the value for all other Laue classes is
larger since 0.8. Above mentioned features are typical of non-
merohedral twins, where the reciprocal lattices do not overlap
exactly and only some of the reflections are affected by the twin-
ꢁ1
R
¼31.32 min
(
40.5%), 33.48 min (59.5%).
2
2
ning. Therefore, after refinement of the structure to R of 0.27, the
2
2
4.6.5. Asymmetric addition of diethylzinc to benzaldehyde in the
o c
69 reflections with F >>F were removed from the intensity data
presence of ligands 11e14. To a solution of 11e14 (2.5 mol %) in
anhydrous benzene (5 mL) was added diethylzinc (3 mmol, 1.0 M
file assuming that they are affected by the twinning and the
remaining reflections are contributed to a single twin domain. The
refinement on the modified intensity data file gave R of 0.048 and
acceptable values of other refinement parameters.
solution in hexane) under argon and the reaction was stirred for
ꢀ
1
0 min at room temperature. The solution was cooled at 0 C, and
benzaldehyde (1 mmol) was added slowly. After being stirred for
ꢀ
2
h at 0 C, and 12 h at room temperature, the reaction was
4.7.3. Crystal data of 6. C14
H
14
N
2
OS
2
, M¼290.39, triclinic, space
ꢁ
quenched with 1 M aqueous HCl (20 mL). The mixture was
extracted with Et O, and the combined organic layer dried over
Na SO . After removal of the solvent under reduced pressure, the
residue was purified by column chromatography (hexane/ethyl
acetate, 10:1) to afford 1-phenyl-1-propanol (15) as a colorless
liquid in 43e74% yield. The ee values of 15 range from 3 to 7%.
group P1, a¼8.2719 (7), b¼9.1916 (8), c¼10.2434 (9) A,
a
¼67.289
ꢀ
ꢁ
3
2
(1),
b
¼78.987 (1),
g
¼83.799 (1) , V¼704.70 (11) A , Z¼2,
ꢁ
3
ꢁ1
,
2
4
d
calcd¼1.369 Mg
m
,
F(000)¼304,
m
(Mo
Ka
)¼0.370 mm
ꢀ
T¼293 K, 11,741 measured reflections (
q
range 2.18e24.84 ), 2423
unique reflections (Rint¼0.013), final R¼0.029, wR¼0.082, S¼1.075
for 2231 reflections with I>2 (I).
s
4
.7. X-ray structure determinations
4.8. Theoretical calculations
The theoretical calculations at the DFT/B3LYP level with 6-
X-ray data of 5 were collected on the Kuma KM4 diffractometer;
ꢁ
23
crystal sizes 0.40ꢂ0.40ꢂ0.10 mm, Cu K
a
(l
¼1.54178 A) radiation,
u/
311þþG(d,p) basis set implemented in GAUSSIAN 03
were

3104
J. Ławecka et al. / Tetrahedron 67 (2011) 3098e3104
carried out via Natural Bond Order (NBO) analysis to investigate the
conformational preferences of 4e6. The structures were fully op-
timized without any symmetry constraint and the initial geome-
tries were built from their crystallographic data. The total energies
and dipole moments for molecules 4e6 are summarized in Table 2
A.; Harriman, A. Inorg. Chem. 2003, 42, 3466; (f) Yam, V. W. W.; Ko, C. C.; Chu, B.
W. K.; Zhu, N. Dalton Trans. 2003, 3914; (g) Dutta, S. K.; Gan, D.; Perkovic, M. W.
Eur. J. Inorg. Chem. 2003, 6, 2812; (h) Ghassan, B.; Leygue, N.; Galaup, C.; Mestre,
B.; Picard, C. Tetrahedron Lett. 2009, 50, 6525.
6. (a) Nabeshima, T.; Aoki, T.; Yano, Y. Tetrahedron Lett. 1997, 48, 8323; (b) Hopkins,
R. B.; Albert, J. S.; van Engen, D.; Hamilton, A. D. Bioorg. Med. Chem. 1996, 4,
1121; (c) Lee, C.-S.; Teng, P.-F.; Wong, W.-L.; Kwong, H.-L.; Chan, A. S. C. Tet-
0
in Supplementary data. The structure of 5,5 -bi-1,2,4-triazine
rahedron 2005, 61, 7924.
thiamacrocyle with four CH
2
groups in thiaalkyl chain was modeled
7. (a) Newkome, G. R.; Nayak, A.; Fronczek, F.; Kawato, T.; Taylor, H. C. R.; Meade,
L.; Mattice, W. J. Am. Chem. Soc. 1979, 101, 4472; (b) Newkome, G. R.; Kiefer, G.
E.; Kohli, D. K.; Xia, Y.-J.; Fronczek, F. R.; Baker, G. R. J. Org. Chem. 1989, 54, 5105.
de novo and its total energy, dipole moment and geometrical pa-
rameters (bond lengths, angles and torsion angles) obtained after
energy minimization and geometry optimization are presented in
Table 3 in Supplementary data.
8. Buhleier, E.; Vogtle, F. Liebigs Ann. Chem. 1977, 1080.
9. Newkome, G. R.; Nayak, A.; McClure, G. L.; Danesh-Khoshboo, F.; Broussard-
Simpson, J. J. Org. Chem. 1977, 42, 1500.
10. Mattice, W. L.; Newkome, G. R. J. Am. Chem. Soc. 1979, 101, 4477.
1
1. Wessjohann, L. A.; Rivera, D. G.; Vercillo, O. E. Chem. Rev. 2009, 109, 796.
Acknowledgements
12. Binauld, S.; Hawker, C. J.; Fleury, E.; Drockenmuller, E. Angew. Chem., Int. Ed.
2
009, 48, 6654.
3. Becer, C. R.; Hoogenboom, R.; Schubert, U. S. Angew. Chem., Int. Ed. 2009, 48,
900.
1
The authors thank to Mr. Marek Grzegorczyk from Siedlce Uni-
versity for his assistance in the interpretation of UV/vis data.
4
14. qawecka, J.; Karczmarzyk, Z.; Woli nꢀ ska, E.; Branowska, D.; Rykowski, A. Eur. J.
Org. Chem. 2010, 4868.
1
1
5. Raw, S. A.; Taylor, R. J. K. Adv. Heterocycl. Chem. 2010, 100, 75.
6. Branowska, D. Synthesis 2003, 2096.
7. Davis, F. A.; Reddy, T. R.; Weismiller, M. C. J. Am. Chem. Soc. 1989, 111, 5964.
18. Noyori, R.; Kitamura, M. Angew. Chem., Int. Ed. 1991, 30, 49.
9. Allen, F. H.; Kennard, O.; Watson, D. G.; Brammer, L.; Orpen, A. G.; Taylor, R.
Supplementary data
1
Selected torsion angles. Supplementary data associated with
this article can be found in online version at doi:10.1016/
j.tet.2011.02.081.
1
J. Chem. Soc., Perkin Trans. 2 1987, S1.
2
0. Sheldrick, G. M. Acta Crystallogr. 2008, A64, 112.
2
2
1. Farrugia, L. J. J. Appl. Crystallogr. 1999, 32, 837.
2. M u€ ller, R.; Herbst-Irmer, A. L.; Spek, T. R.; Schneider, M. R. Salwaya, Crystal
References and notes
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