O. Mouhtady et al. / Tetrahedron Letters 47 (2006) 4125–4128
4127
by column chromatography on silica gel (eluent: pentane/
AcOEt: 90/10) as a green yellow oil contaminated by
approximately 30% (1H NMR determination) of (R)-6,60-
bromochlorosulfonyl-2,20-bis(hexyloxy)-1,10-binaphthyl (5b)
as shown by mass spectrometry. The mixture of
compounds 5 was used in the next reaction without further
purification and gave the following NMR signals. 1H
NMR (300 MHz, CDCl3) d 0.61–0.65 (m, 3H, Me), 0.80–
1.15 (m, 6H, CH2), 1.37 (q, J = 6 Hz, 2H, OCH2CH2),
3.98 (m, 2H, OCH2CH2), 7.18 (d, J = 9 Hz, 1H), 7.17 (d,
J = 9 Hz, 1H), 7.52 (d, J = 12 Hz, 1H), 7.62 (dd, J = 9,
3 Hz, 1H), 8.10 (d, J = 9 Hz, 1H), 8.49 (d, J = 2 Hz, 1H),
8.55 (d, J = 2 Hz, 1H); 13C NMR (75 MHz, CDCl3) d
13.8, 22.4, 25.3, 28.9, 31.1, 69.2, 116.5, 116.6, 118.8, 118.9,
121.6, 121.9, 126.6, 126.7, 126.8, 126.9, 128.8, 129.5, 132.3,
132.4, 136.6, 136.7, 138.7, 141.6, 158.1, 158.2.
the imine derived from 4-chlorobenzaldehyde (Table 1,
entry 12).3a In preliminary experiments we have found
that 1 is also effective for this reaction, although further
optimization is required (Table 1, entries 13 and 14).
Interestingly, when racemic 3,30-trifluoromethanesulfo-
nyl-2,20-dihydroxy-1,10-binaphthyl5 was used in place
of 1 (same conditions in entry 5) the reaction proceeded
in only 17% yield.
In conclusion, we have shown that the introduction of
trifluoromethanesulfonyl groups in the 6,60 positions
on the chiral backbone generates highly active zirco-
nium-based catalyst for Mannich-type reactions. The
catalysis of other reactions with this ligand and its deriv-
atives is currently under investigation in our laboratory.
10. Garlyauskajte, R. Y.; Sereda, S. V.; Yagupolskii, L. M.
Tetrahedron 1994, 50, 6891–6906.
11. Synthesis of compound 6. Into a 250 mL round bottomed
flask was placed 5 (6 g, 9.2 mmol) in 100 mL of anhydrous
acetonitrile. Then, AgF (2.8 g, 22.07 mmol) was added
under argon and the resulting suspension was stirred for
4 h at rt. After this time, the suspension was filtered over
celite and the solvents were evaporated under reduced
pressure. Compound 6 (5.43 g, 95% yield) was obtained as
a brown orange oil and was pure enough to be used
Acknowledgement
We wish to thank Chantal Zedde for the HPLC analysis
and Magnus Bebbington for his kind contribution to the
preparation of the manuscript.
20
in the next step without purification. ½aꢁD +56.7 (c 2.38,
References and notes
CH2Cl2); IR (KBr pellet) 3474, 1611, 1498, 1465, 1356,
1
1281, 1216, 1131, 1084, 1069, 898, 848, 666, 631 cmꢀ1; H
1. Noyori, R.; Tomino, I.; Tanimoto, Y. J. Am. Chem. Soc.
1979, 101, 3129–3131.
2. (a) Chen, Y.; Yekta, S.; Yudin, A. K. Chem. Rev. 2003,
103, 3155–3211; (b) Cook, G. R.; Kargbo, R.; Maity, B.
Org. Lett. 2005, 7, 2767–2770.
3. (a) Ishitani, H.; Ueno, M.; Kobayashi, S. J. Am. Chem.
Soc. 2000, 122, 8180–8186; (b) Ueno, M.; Ishitani, H.;
Kobayashi, S. Org. Lett. 2002, 4, 3395–3397.
NMR (300 MHz, CDCl3) d 0.69–0.75 (m, 3H, Me), 0.80–
1.15 (m, 6H, CH2), 1.45 (m, 2H, OCH2CH2), 4.06 (m, 2H,
OCH2CH2), 7.26 (d, J = 9 Hz, 1H), 7.60 (d, J = 11 Hz,
1H), 7.65 (dd, J = 9, 2 Hz, 1H), 8.18 (d, J = 9 Hz, 1H),
8.65 (d, J = 1.8 Hz, 1H); 13C NMR (75 MHz, CDCl3) d
13.8, 22.4, 25.3, 28.9, 31.1, 69.2, 116.4, 118.7, 122.7, 126.7,
126.9, 127.0, 127.2, 131.4, 131.9, 136.9, 158.0; 19F NMR
(188 MHz, CDCl3) d 103.3.
4. (a) Goumont, R.; Kizilian, E.; Buncel, E.; Terrier, F. Org.
Biomol. Chem. 2003, 1, 1741–1748; (b) Goumont, R.;
Faucher, N.; Moutiers, G.; Tordeux, M.; Wakselman, C.
Synthesis 1997, 691–695.
12. Movchun, V. N.; Kolomeitsev, A. A.; Yagupolskii, Y. L.
J. Fluorine Chem. 1995, 70, 255–257.
13. Synthesis of compound 7. Into a 100 mL flask were added
successively under argon TASF (472 mg, 1.713 mmol) and
35 mL of dry pentane, and the suspension was cooled to
+5 °C. Then, a solution of 6 (5.3 g, 8.56 mmol) in 20 mL
of dry THF was added. A solution of TMSCF3 (4.87 g,
34.24 mmol) in 20 mL of dry pentane was added dropwise
and the suspension was stirred for 24 h. After this time,
water (50 mL) was added and the organic materials were
extracted with dichloromethane. Compound 7 (4.92 g,
80% yield) was isolated by column chromatography on
silica gel (eluent: pentane/AcOEt: 95/5) as an orange
5. The synthesis of racemic 3,30-trifluoromethanesulfonyl-
2,20-dihydroxy-1,10-binaphthyl has been recently reported
using the anionic thia-Fries rearrangement of 1,10-bi-2,20-
naphthol bis(trifluoromethanesulfonate): Charmant, J. P.
H.; Dyke, A. M.; Lloyd-Jones, G. C. J. Chem. Soc. Chem.
Commun. 2003, 380–381.
6. (a) Hendrickson, J. B.; Bair, K. W. J. Org. Chem. 1977, 42,
3875–3878; (b) Singh, R. P.; Cao, G.; Kirchmeier, R. L.;
Shreeve, J. M. J. Org. Chem. 1999, 64, 2873–2876; (c)
Creary, X. J. Org. Chem. 1980, 45, 2727–2729; (d) Pevere,
V.; Quiclet-Sire, B.; Zard, S.; Bertrand F. PCT Int. WO
00/00467.
7. Hamada, T.; Yonemitsu, O. Synthesis 1986, 852–854.
8. Hu, Q. S.; Vitharana, D.; Liu, G.; Jain, V.; Wagaman, M.
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1082–1084.
9. Synthesis of compound 5. To a vigorously stirred solution
of sulfur dioxide (20 mL) in THF (230 mL) cooled to
ꢀ70 °C was gradually added through a teflon canula a
solution of the aryllithium prepared from 3 (10.65 g,
17.4 mmol) in THF (120 mL) and 1.6 M n-butyllithium in
hexanes (22 mL) at ꢀ60 °C under argon. The addition was
complete in 5 min and the reaction mixture was allowed to
warm to room temperature over 5 min. After removal of
the solvents in vacuo, the residual crude lithium sulfinate 4
was washed with ether and used in the next reaction
without further purification. Following the procedure
previously reported,7 compound 5a (9.07 g) was isolated
20
viscous oil; . ½aꢁD +45.5 (c 0.85, CH2Cl2); 1H NMR
(300 MHz, CDCl3) d 0.59–0.63 (m, 3H, Me), 0.80–1.15
(m, 6H, CH2), 1.35 (m, 2H, OCH2CH2), 3.98 (m, 2H,
OCH2CH2), 7.23 (d, J = 9 Hz, 1H), 7.53 (d, J = 9 Hz,
1H), 7.58 (dd, J = 9, 3 Hz, 1H), 8.13 (d, J = 9 Hz, 1H),
8.60 (d, J = 3 Hz, 1H); 13C NMR (75 MHz, CDCl3) d
13.7, 22.3, 25.2, 28.9, 31.1, 69.2, 116.4, 118.6, 120.0
(q, J = 326 Hz, CF3), 125.1, 127.3, 132.3, 137.5, 158.4; 19
NMR (188 MHz, CDCl3) d ꢀ2.86.
F
14. Bhatt, M. V.; Kulkarni, S. U. Synthesis 1983, 249–282,
and references cited.
15. Synthesis of compound 1. Into a 250 mL flask were added
7 (4.65 g, 6.47 mmol) and toluene (130 mL). Then BBr3
(8.1 g, 32.35 mmol) was added dropwise and the solution
was stirred at RT for 24 h. Water (50 mL) was added
followed by a saturated aqueous solution of sodium
bicarbonate (50 mL) and the organic materials were
extracted with ether (100 mL). After removal of the
solvents under reduced pressure, compound 1 (3.1 g,