K. Nakazono et al. / Tetrahedron Letters 49 (2008) 2397–2401
2401
6. (a) Dvornikovs, V.; House, B. E.; Kaetzel, M.; Dedman, J. R.;
Smithrud, D. B. J. Am. Chem. Soc. 2003, 125, 8290–8301; (b) Bao, X.;
Isaacsohn, I.; Drew, A. F.; Smithrud, D. B. J. Am. Chem. Soc. 2006,
128, 12229–12238; (c) Bao, X.; Isaacsohn, I.; Drew, A. F.; Smithrud,
D. B. J. Org. Chem. 2007, 72, 3988–4000; (d) Wang, X.; Bao, X.;
McFariand-Mancini, M.; Isaacsohn, I.; Drew, A. F.; Smithrud, D. B.
J. Am. Chem. Soc. 2007, 129, 7284–7293.
Ber. 1972, 105, 3591–3599; (c) Schill, G.; Beckmann, W.; Vetter, W.
Angew. Chem. 1973, 85, 661–662; (d) Harrison, I. T. J. Chem. Soc.,
Perkin Trans. 1 1974, 301–304.
10. It is possible to deprotonate sec-ammonium to sec-amine group of
crown ether-containing rotaxane by i-Pr2NEt or electrochemical
reduction, when the rotaxane has another suitable cationic sites for
the crown ether wheel such as 4,40-bipyridinium group on the axle
component: (a) Mart´ınez-D´ıaz, M.-V.; Spencer, N.; Stoddart, J. F.
Angew. Chem., Int. Ed. 1997, 36, 1904–1907; (b) Ashton, P. R.;
Ballardini, R.; Balzani, V.; Baxter, I.; Credi, A.; Fyfe, M. C. T.;
7. Preparation of tert-ammonium-type rotaxane 2ꢀPF6 from 1: A mixture
of tert-ammonium salt 1 (125 mg, 0.300 mmol) and DB24C8 (202 mg,
0.450 mmol) in chloroform (0.6 mL) was stirred at 0 °C for 10 min.
To the mixture were added 3,5-dimethylbenzoic anhydride (106 mg,
0.380 mmol) and tributylphosphane (7.4 lL, 0.03 mmol) and the
mixture was stirred at 0 °C for 48 h. Diluted sodium hydrogen
carbonate solution was added and organic layer was separated. The
organic layer was washed with 2 M HCl and brine. The resulting
organic layer was dried over anhydrous magnesium sulfate, filtered,
and evaporated. The residue was subjected to preparative HPLC
using chloroform as an eluent to give colorless solid (2ꢀPF6, 9.3 mg,
3.0%). Mp 99–100 °C; 1H NMR (CDCl3, 400 MHz) d 7.73 (br, 1H),
7.68–7.65 (m, 4H), 7.29–7.23 (m, 2H), 7.20 (s, 1H), 7.05 (s, 2H), 6.90–
6.87 (m, 5H), 6.81–6.77 (m, 4H), 5.20–5.15 (m, 3H), 4.94 (dd,
J = 2.3 Hz, J = 13.1 Hz, 1H), 4.50–4.44 (m, 1H), 4.24–4.19 (m, 1H),
4.11–4.10 (m, 8H), 3.79–3.70 (m, 8H), 3.60–3.50 (m, 8H), 2.94–2.92
(m, 3H), 2.36 (s, 6H), 2.21 (s, 6H) ppm. 13C NMR (100 MHz, CDCl3)
d 147.2, 147.1, 138.3, 138.1, 137.5, 134.8, 132.1, 130.4, 129.9, 129.8,
129.2, 127.8, 127.3, 121.5, 121.3, 111.9, 111.7, 77.2, 76.6, 71.7, 71.5,
70.4, 70.3, 68.1, 68.0, 65.8, 60.9, 60.4, 39.3, 29.7, 21.1 ppm. IR (KBr)
1718, 1578, 1444, 1375, 1196, 856, 670 cmꢁ1. MALDI-TOF MS
´
´
Gandlfi, M. T.; Lopez, M. G.; Dıaz, M. V. M.; Piersanti, A.; Spencer,
N.; Stoddart, J. F.; Venturi, M.; White, A. J. P.; Williams, D. J. J.
Am. Chem. Soc. 1998, 120, 11932–11942; (c) Lin, C. F.; Lai, C. C.;
Liu, Y. H.; Peng, S. M.; Chiu, S. H. Chem. Eur. J. 2007, 13, 4350–
4355; (d) Chen, N. C.; Huang, P. Y.; Lai, C. C.; Liu, Y. H.; Wang, Y.;
Peng, S. H.; Chiu, S. H. Chem. Commun. 2007, 4122–4224.
11. Preparation of 4: To a solution of rotaxane 2ꢀPF6 (25 mg, 0.025 mmol)
in CH3CN was added DBU (37 lL, 0.25 mmol). The colorless
suspension was heated to 70 °C to stir for 24 h. The mixture was
poured into water (30 mL) and stirred for 30 min. The precipitate
formed was collected by filtration and washed with water. The solid
material was dried under reduced pressure. Colorless powder (21 mg,
100% yield). Mp 158 °C, 1H NMR (CDCl3, 400 MHz) d 8.13–8.10 (m,
4H), 7.11 (d, J = 8.0 Hz, 2H), 7.06 (s, 2H), 6.90–6.81 (m, 10H), 6.00
(s, 2H), 4.11–4.03 (m, 8H), 3.73–3.64 (m, 8H), 3.41 (s, 2H), 3.34 (s,
2H), 3.28–3.24 (m, 4H), 2.27 (s, 6H), 2.18 (s, 6H), 2.09 (s, 3H) ppm.
13C NMR (100 MHz, CDCl3) d 167.2, 148.6, 139.5, 137.5, 136.5,
136.2, 134.0, 130.9, 128.6, 128.4, 128.2, 128.2, 126.8, 120.4, 111.5,
77.2, 69.5, 69.3, 67.9, 67.0, 62.0, 61.3, 42.1, 21.3, 20.8 ppm. IR (KBr)
þ
(matrix DHBA) [2ꢀPF6–PF6] calcd for C51H64NO10 850.4530, found
850.2540.
2917, 1720, 1505, 1455, 1321, 1251, 1218, 1127, 1037, 739 cmꢁ1
.
8. N-Methylation of sec-ammonium-type rotaxane 3ꢀPF6: To a solution
MALDI-TOF MS (matrix DHBA) [4+H] calcd for C51H64NO10
850.4530, found 850.5493.
3
of rotaxane 3ꢀPF6 (98 mg, 0.10 mmol) in DMF (1 mL) were added
formic acid (98 mg, 2.0 mmol) and paraformaldehyde (60 mg,
2.0 mmol). The mixture was stirred at 70 °C for 24 h, cooled to room
temperature, and poured into water (50 mL) and stirred for 1 h at rt.
The precipitate formed was collected by filtration to afford tert-
12. The refinement of the structure failed to be completed due to the
efflorescent nature of the crystal and poor reflection data. Still, the
atom-connecting scheme and relative arrangement of the molecules
have been confirmed. Crystal data for 4ꢀ2(i-PrOH) obtained by
recrystallization from chloroform–i-PrOH–ethyl acetate: orthorhom-
ammonium rotaxane 2ꢀPF6 as
a colorless solid in 100% yield
˚
(100 mg).
bic, Pna21, a = 15.365(5), b = 29.691(9), c = 12.193(4) A, V =
3
calcd = 1.158 g cmꢁ3
,
F000 = 2096, l =
˚
9. The yield (3.0%) is much higher than that expected by statistical
complexation: (a) Harrison, I. T. J. Chem. Soc., Chem. Commun.
1972, 4, 231–232; (b) Schill, G.; Murjahn, K.; Beckmann, W. Chem.
5562.6(29) A , Z = 4,
q
0.80 cmꢁ1
12,390, R1 = 0.106 [I > 2r(I)], wR2 = 0.260 (all data).
, reflection measured 47,401, independent reflections