European Journal of Organic Chemistry
10.1002/ejoc.201900073
FULL PAPER
were dried in a solvent purification system by passing it through an
activated alumina column before use. Column chromatography was
carried out using silica gel (60 Å, 70-200 μm) as stationary phase, and
TLC was performed on precoated silica gel on aluminium cards (0.25 mm
thick, with fluorescent indicator 254 nm) and observed under UV light. All
melting points were determined on a Kofler hot-plate melting point
8.3 Hz), 7.64 (t, 2H, J = 7.8 Hz), 7.00 (s, 8H), 5.97 (s, 2H), 5.27 (dd, 4H,
J = 14.2, 9.1 Hz), 3.71 (dd, 4H, J = 14.2, 1.2 Hz), 3.35-3.25 (m, 4H),
2.96-2.88 (m, 4H), 1.62-1.48 (m, 4H), 1.38-1.14 (m, 8H), 0.92 (t, 6H, J =
13
7.3 Hz), 0.68-0.48 (m, 10H) ppm. C NMR (75 MHz, CDCl
3
): = 165.5
(CO), 165.2 (CO), 138.2 (C), 133.4 (C), 132.3 (CH), 129.6 (CH), 129.1
(CH), 128.4 (CH), 122.8 (CH), 49.1 (CH
(CH ), 30.2 (CH ), 20.3 (CH ), 19.8 (CH
2
), 48.0 (CH
), 13.9 (CH
2
), 43.5 (CH
), 13.7 (CH
2
), 32.3
) ppm.
1
13
apparatus and are uncorrected. H- and C-NMR spectra were recorded
2
2
2
2
3
+
3
1
at 298 K on 300 and 400 MHz spectrometers. H NMR chemical shifts
67 6 6
HRMS (ESI+) m/z calcd for C52H N O [M + H] 871.5117, found
are reported relative to Me
resonances of the corresponding deuterated solvent whereas C NMR
spectra are reported relative to Me Si using the carbon signals of the
4
Si and were referenced via residual proton
871.5123.
13
4
Rotaxane 2b was obtained using the described method from thread 4b
0.50 g, 1.77 mmol). The resulting residue was subjected to column
chromatography (silica gel) using a CHCl /MeOH (40/1) mixture. The
solvent was removed under reduced pressure to give the title product as
deuterated solvent. Abbreviations of coupling patterns are as follows: br,
broad; s, singlet; d, doublet; t, triplet; q, quadruplet; m, multiplet. Coupling
constants (J) are expressed in Hz. High resolution mass spectra (HRMS)
were obtained using a time-of-flight (TOF) instrument equipped with
electrospray ionization (ESI). The irradiation experiments were carried
out in quartz tubes in a photoreactor Luzchem LZC-4V under 254 nm (62
(
3
1
a white solid (446 mg, 31%); mp 262-264 ºC; H NMR (300 MHz, CDCl
3
):
=
8.86 (s, 2H), 8.35 (d, J= 7.7 Hz, 4H), 7.76-7.63 (m, 6H), 7.01 (s, 8H),
5
3
4
.95 (s, 2H), 5.35-5.27 (dd, J= 14.1, 9.3 Hz, 4H), 3.71 (d, J= 14.1 Hz, 4H),
.35-3.20 (m, 4H), 2.95-2.85 (m, 4H), 1.70-1.55 (m, 4H), 1.30-1.20 (m,
-
2
-2
W·m ) and 312 nm (56 W·m ).
1
3
H), 0.95 (t, J= 7.3 Hz, 6H), 0.24 (t, J= 7.2 Hz, 6H). C NMR (75 MHz,
): = 165.5 (CO), 165.3 (CO), 138.3 (C), 133.5 (C), 132.3 (CH),
129.8 (CH), 129.0 (CH), 128.4 (CH), 122.7 (CH), 50.9 (CH ), 50.1 (CH ),
3.4 (CH ), 31.1 (CH ), 23.5 (CH ), 21.4 (CH ), 11.8 (CH ), 10.5 (CH
[M + H] 815.0107; found:
[
29]
[13m]
[13m]
Materials. Threads 4a-c
and 4d
and rotaxane 2d
were
CDCl
3
prepared as previously reported.
2
2
4
2
2
2
2
3
3
)
+
ppm. HRMS (ESI+) m/z calcd for C48
59 6 6
H N O
Synthesis of thread 4e. To a stirred solution of (E)-4-(dibenzylamino)-4-
[
29]
815.0109.
2 2
oxobut-2-enoic acid (2.00 g, 6.78 mmol) in anhydrous CH Cl (50 mL)
was added dipropylamine (1.10 mL, 8.14 mmol), HOBt (915 mg, 6.78
mmol) and DMAP (82 mg, 0.68 mmol). The reaction mixture was cooled
to 0ºC and DCC (1.40g, 6.78 mmol) was added. After 30 min, the
reaction was warmed to room temperature and was stirred for 24 h. After
this time the resulting suspension was filtered and the filtrate was
washed with an aqueous solution of 1M HCl (2 x 30 mL), saturated
Rotaxane 2e was obtained by using the previously described method
from thread 4b (0.50 g, 1.32 mmol). The crude product was subjected to
column chromatography on silica gel using a CHCl
3
/MeOH (40/1) mixture,
to give the title product as a white solid (303 mg, 25%). mp 265-267 ºC;
1
3
H NMR (300 MHz, CDCl , 298 K) = 8.81 (s, 1H), 8.51 (s, 1H), 8.39 (d,
NaHCO
over anhydrous MgSO
resulting residue was subjected to column chromatography (silica gel)
using a mixture of hexane/AcOEt (3/1). The solvent was removed under
3
(2 x 30 mL) and brine (2 x 30 mL). The organic phase was dried
J= 7.6 Hz, 2H), 8.20 (d, J= 7.7 Hz, 2H), 7.69 (t, J= 7.7 Hz, 1H), 7.63-7.43
(m, 5H), 7.42-7.36 (m, 5H), 7.24-7.06 (m, 3H), 6.91-6.76 (m, 10H), 6.02
(d, J= 14.5 Hz, 1H), 5.96 (d, J= 14.5 Hz, 1H), 5.30-5.05 (m, 4H), 4.57 (s,
2H), 4.35 (s, 2H), 3.71 (d, J= 13.9 Hz, 2H), 3.45 (d, J= 13.9 Hz, 2H),
3.22-3.13 (m, 2H), 2.88-2.79 (m, 2H), 1.62-1.46 (m, 2H), 1.27-1.14 (m,
2H), 0.86 (t, J= 7.4 Hz, 3H), 0.19 (t, J= 7.4 Hz, 3H); C NMR (75 MHz,
3
CDCl , 298 K) = 166.5 (CO), 165.5 (CO), 165.4 (CO), 164.8 (CO),
138.1 (C), 138.0 (C), 135.9 (C), 134.6 (C), 133.6 (C), 133.2 (C), 132.6
(CH), 132.0 (CH), 130.0 (CH), 129.9 (CH), 129.4 (CH), 129.2 (CH), 129.0
(CH), 128.9 (CH), 128.9 (CH), 128.5 (CH), 125.9 (CH), 122.8 (CH), 122.1
4
and concentrated under reduced pressure. The
reduced pressure to give the title product as a yellow oil (4e, 2.10 g,
1
13
8
7
2
1
2 %); H NMR (400 MHz, CDCl
3
, 298 K) = 7.51 (d, J= 14.6 Hz, 1H),
.46 (d, J= 14.6 Hz, 1H), 7.37-7.22 (m, 8H), 7.18-7.13 (m, 2H), 4.66 (s,
H), 5.51 (s, 2H), 3.37-3.30 (m, 4H), 1.68-1.52 (m, 4H), 0.93 (t, J= 7.3 Hz,
H), 0.83 (t, J= 7.4 Hz, 1H); C NMR (101 MHz, CDCl , 298 K) = 166.1
3
13
(
(
(
(
CO), 164.7 (CO), 136.9 (C), 136.1 (C), 132.9 (CH), 131.0 (CH), 129.0
CH), 128.8 (CH), 128.4 (CH), 127.9 (CH), 127.7 (CH), 126.8 (CH), 50.2
(CH), 51.8 (CH
(CH ), 23.6 (CH
for C56 [M + H] 911.4491, found 911.4474.
2
), 51.6 (CH
), 21.3 (CH
2
), 50.9 (CH
), 11.7 (CH
2
), 50.2 (CH ), 43.6 (CH
2
2
) , 43.2
CH
CH
2
), 50.0 (CH
), 11.2 (CH
2
), 48.7 (CH
); HRMS (ESI) calcd for C24
2
), 48.6 (CH
2
), 23.1 (CH
2
), 21.0 (CH
2
), 11.5
[M + H] 379.2380,
2
2
2
3
), 10.4 (CH ); HRMS (ESI) calcd
3
+
+
3
3
H N O
31 2 2
59 6 6
H N O
found 379.2387.
Rotaxane 3a was obtained using the described method from thread 4a
General procedure for the synthesis of the [2]rotaxanes 2a-e and 3a-
b. The thread (1 equiv.) and Et N (24 equiv.) in anhydrous CHCl (300
mL) were stirred vigorously while solutions of p-xylylenediamine (8
equiv.) in anhydrous CHCl (20 mL) and the corresponding acid
dichloride (8 equiv.) in anhydrous CHCl (20 mL) were simultaneously
added over a period of 4 h using motor-driven syringe pumps. After a
further 4 h, the resulting suspension was filtered through a Celite pad and
washed with water (2 x 50 mL), a solution of HCl 1M (2 x 50 mL), a
(950 mg, 2.79 mmol). The resulting residue was subjected to column
3
3
chromatography (silica gel) using a CHCl
3
/MeOH (98/2) mixture. The
solvent was removed under reduced pressure to give the title product as
1
3
a white solid (192 mg, 7%); mp > 250 ºC; H NMR (400 MHz, CDCl
3
):
=
3
7.09 (d, J = 9.1 Hz, 4H), 6.90 (s, 8H), 5.84 (s, 2H), 4.92-4.87 (m, 4H),
3.60 (d, J = 14.1 Hz, 4H), 3.35-3.31 (m, 4H), 3.17-3.13 (m, 4H), 2.68-2.60
(m, 2H), 2.31-2.10 (m, 12H), 1.85-1.82 (m, 4H), 1.69-1.54 (m, 18H), 1.44-
1
3
1.33 (m, 8H), 1.04-0.99 (m, 12H) ppm. C NMR (100 MHz, CDCl
177.6 (CO), 164.8 (CO), 137.7 (C), 129.1 (C), 127.4 (CH), 48.8 (CH
48.0 (CH ), 43.6 (CH ), 41.7 (CH ), 39.7 (CH ), 38.7 (CH ), 35.3 (CH
32.5 (CH ), 30.0 (CH ), 28.2 (CH), 20.7 (CH ), 20.6 (CH ), 14.2 (CH
14.0 (CH ) ppm. HRMS (ESI+) m/z calcd for C59
87.6609, found 987.6673.
3
):
=
),
),
saturated solution of NaHCO
organic phase was then dried over MgSO
3
(2 x 50 mL) and brine (2 x 50 mL). The
, and the solvent was removed
2
2
4
2
2
2
2
2
under reduced pressure. The resulting solid was subjected to column
chromatography (silica gel) to yield unconsumed thread and [2]rotaxane.
2
2
2
2
2
),
+
3
83 6 6
H N O [M + H]
9
Rotaxane 2a was obtained using the described method from thread 4a
(
0.50 g, 1.48 mmol). The resulting residue was subjected to column
Rotaxane 3b was obtained using the described method from thread 4b
chromatography (silica gel) using a CHCl /MeOH (40/1) mixture. The
3
(788 mg, 2.8 mmol). The resulting residue was subjected to column
solvent was removed under reduced pressure to give the title product as
a white solid (682 mg, 53%); mp > 300 ºC (decomp.); H NMR (3.00 MHz,
chromatography (silica gel) using a CHCl
3
/AcOEt (3/1) mixture. The
1
solvent was removed under reduced pressure to give the title product as
1
CDCl
3
): = 8.86 (s, 2H), 8.32 (dd, 4H, J = 7.8, 0.9 Hz), 7.75 (d, 4H, J =
a white solid (130 mg, 5%); mp > 250 ºC; H NMR (400 MHz, CDCl
3
):
=
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