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Synlett
X.-R. Zhang et al.
Letter
to the more challenging thiophene substrates. We hope this
protocol would be applicable to more asymmetric alkyla-
tion reactions of furan and thiophene substances. More re-
sults will be reported in due course.
S.; Berger, R.; Leighton, J. L. J. Am. Chem. Soc. 2005, 127, 2858.
(d) Majer, J.; Kwiatkowski, P.; Jurczak, J. Org. Lett. 2009, 11,
4636. (e) Aikawa, K.; Asai, Y.; Hioki, Y.; Mikami, K. Tetrahedron:
Asymmetry 2014, 25, 1104.
(
6) Brown, S. P.; Goodwin, N. C.; MacMillan, D. W. C. J. Am. Chem.
Soc. 2003, 125, 1192.
Funding Information
(7) (a) Li, J.-L.; Yue, C.-Z.; Chen, P.-Q.; Xiao, Y.-C.; Chen, Y.-C. Angew.
Chem. Int. Ed. 2014, 53, 5449. (b) Yang, G.-J.; Du, W.; Chen, Y.-C.
J. Org. Chem. 2016, 81, 10056. For HOMO activation of arene
systems for [4+2] cycloadditions, see: (c) Jiang, H.; Rodríguez-
Escrich, C.; Johansen, T. K.; Davis, R. L.; Jørgensen, K. A. Angew.
Chem. Int. Ed. 2012, 51, 10271. (d) Rodríguez-Escrich, C.; Davis,
R. L.; Jiang, H.; Stiller, J.; Johansen, T. K.; Jørgensen, K. A. Chem.
Eur. J. 2013, 19, 2932. (e) Xiao, Y.-C.; Yue, C.-Z.; Chen, P.-Q.;
Chen, Y.-C. Org. Lett. 2014, 16, 3208. (f) Xiao, B.-X.; Du, W.;
Chen, Y.-C. Adv. Synth. Catal. 2017, 359, 1018.
Natural Science Foundation of China 21372160
Natural Science Foundation of China 21125206
Acknowledgment
We thank Mr. Cai-Zhen Yue for his early exploration on this reaction.
Supporting Information
(8) (a) Wang, W.; Li, H.; Wang, J. Org. Lett. 2005, 7, 1637. (b) Gupta,
V.; Sudhir, S.; Mandal, V. T.; Schneider, C. Angew. Chem. Int. Ed.
2012, 51, 12609.
(9) (a) Saraber, F. C. E.; Dratch, S.; Bosselaar, G.; Jansen, B. J. M.; de
Groot, A. Tetrahedron 2006, 62, 1717. (b) Hashmi, A. S. K.;
Wölfle, M. Tetrahedron 2009, 65, 9021. (c) Kang, B. C.; Shim, S.
Y.; Ryu, D. H. Org. Lett. 2014, 16, 2077. (d) The configuration of
the O-TBS enol ether is confirmed by NOEDS analysis. See the
Supporting Information.
Supporting information for this article is available online at
https://doi.org/10.1055/s-0036-1588831.
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References and Notes
(1) For selected reviews on asymmetric Friedel–Crafts reaction,
see: (a) Bolm, C.; Hildebrand, J. P.; Muñiz, K.; Hermanns, N.
Angew. Chem. Int. Ed. 2001, 40, 3284. (b) Bandini, M.; Melloni,
A.; Umani-Ronchi, A. Angew. Chem. Int. Ed. 2004, 43, 550.
(
10) Donslund, B. S.; Johansen, T. K.; Poulsen, P. H.; Halskov, K. S.;
Jørgensen, K. A. Angew. Chem. Int. Ed. 2015, 54, 13860.
11) Lelais, G.; MacMillan, D. W. C. Aldrichimica Acta 2006, 39, 79.
12) The reaction was carried out with α,β-unsaturated aldehyde 3
(
(
(
(
c) Poulsen, T. B.; Jørgensen, K. A. Chem. Rev. 2008, 108, 2903.
d) You, S.-L.; Cai, Q.; Zeng, M. Chem. Soc. Rev. 2009, 38, 2190.
(
0.15 mmol) and silyl enol ether 2 (0.1 mmol) in CHCl (1.0 mL)
3
(
2) Paras, N. A.; MacMillan, D. W. C. J. Am. Chem. Soc. 2001, 123,
370.
in the presence of secondary amine catalyst C4 (4.9 mg, 0.02
mmol) and TFA (2.2 mg, 0.02 mmol) at –20 °C. After completion,
the solution was concentrated, and the residue was dissolved in
MeOH (2 mL), then NaBH4 (5.7 mg, 0.15 mmol) was added in
one portion at r.t. After completion, the solution was concen-
trated and purified by flash chromatography on silica gel (PE–
EtOAc) to afford the chiral product 4. Isolated products have
4
(3) For selected examples, see: (a) Jensen, K. B.; Thorbauge, J.;
Hazell, R. G.; Jørgensen, K. A. Angew. Chem. Int. Ed. 2001, 40, 160.
(b) Austin, J. F.; MacMillan, D. W. C. J. Am. Chem. Soc. 2002, 124,
1172. (c) Evans, D. A.; Scheidt, K. A.; Frandrick, K. R.; Lam, H. W.;
Wu, J. J. Am. Chem. Soc. 2003, 125, 10780. (d) Blay, G.;
Fernandez, I.; Pedro, J. R.; Vila, C. Org. Lett. 2007, 9, 2601.
1
13
been fully characterized by H NMR and C NMR spectroscopy
(e) Chen, W.; Du, W.; Yue, L.; Li, R.; Wu, Y.; Ding, L.-S.; Chen, Y.-
(see the Supporting Information).
C. Org. Biomol. Chem. 2007, 5, 816. (f) Bartoli, G.; Bosco, M.;
Carlone, A.; Pesciaioli, F.; Sambri, L.; Melchiorre, P. Org. Lett.
(S,Z)-3-(5-{2-[(tert-Butyldimethylsilyl)oxy]prop-1-en-1-
yl}furan-2-yl)-3-(4-nitrophenyl)propan-1-ol (4d)
Yield: 35.0 mg (84%), yellow oil; the enantiomeric excess was
determined to be 95% by HPLC analysis [Chiralpak AD-H column
2007, 9, 1403. (g) Sibi, M. P.; Coulomb, J.; Stanley, L. M. Angew.
Chem. Int. Ed. 2008, 47, 9913. (h) He, Y.; Lin, M.; Li, Z.; Liang, X.;
Li, G.; Antilla, J. C. Org. Lett. 2011, 13, 4490. (i) Wang, S.-G.;
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J.-W.; Liu, X.-W.; Gu, Q.; Shi, X.-X.; You, S.-L. Org. Chem. Front.
(
1
5% 2-PrOH–n-hexane, 1.0 mL/min), UV (220 nm), t (minor) =
R
20
1.32 min, tR (major) = 13.22 min]; [α]D = +13.5 (c 0.80 in
1
CHCl ). H NMR (400 MHz, CDCl ): δ = 8.14 (d, J = 8.8 Hz, 2 H),
3
3
7
.41 (d, J = 8.8 Hz, 2 H), 6.35 (d, J = 3.2 Hz, 1 H), 6.13 (d, J = 3.2
Hz, 1 H), 5.34 (s, 1 H), 4.29 (t, J = 7.8 Hz, 1 H), 3.66–3.57 (m, 2 H),
.39–2.33 (m, 1 H), 2.12–2.07 (m, 1 H), 1.95 (s, 3 H), 1.40 (s, 1
2015, 2, 476. (l) Nakamura, S.; Matsuda, N.; Ohara, M. Chem. Eur.
J. 2016, 22, 9478. (m) García-García, C.; Ortiz-Rojano, L.;
Álvarez, S.; Álvarez, R.; Ribagorda, M.; Carreño, M. C. Org. Lett.
2
13
H), 0.95 (s, 9 H), 0.21–0.20 (m, 6 H) ppm. C NMR (100 MHz,
2
2
016, 18, 2224. (n) Zhao, Y.; Wang, L.; Zhao, J. Tetrahedron Lett.
017, 58, 213.
CDCl ): δ = 151.7, 151.6, 150.4, 148.9, 128.7, 123.8, 108.0, 106.6,
3
9
8.7, 60.1, 41.2, 37.1, 25.9, 23.4, 18.4, -3.1 ppm. ESI-HRMS: m/z
(4) (a) Uraguchi, D.; Sorimachi, K.; Terada, M. J. Am. Chem. Soc.
+
calcd for C22H31NO Si + Na : 440.1864; found: 440.1868.
5
2004, 126, 11804. (b) Liu, H.; Xu, J.; Du, D.-M. Org. Lett. 2007, 9,
4725. (c) Majer, J.; Kwiatkowski, P.; Jurczak, J. Org. Lett. 2008, 10,
2955. (d) Adachi, S.; Tanaka, F.; Watanabe, K.; Harada, T. Org.
(
13) To the best of our knowledge, there is only one example involv-
ing the Friedel–Crafts reaction of 2-methoxythiophene under
aminocatalytic conditions, see: Huang, Y.; Walji, A. M.; Larsen,
C. H.; MacMillan, D. W. C. J. Am. Chem. Soc. 2005, 127, 15051.
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Lett. 2009, 11, 5206. (e) Adachi, S.; Tanaka, F.; Watanabe, K.;
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Y.; Komuro, T.; Egawa, F.; Kanomata, K.; Terada, M. Chem. Sci.
(
2003, 15, 743. (b) Stephens, P. J.; Harada, N. Chirality 2010, 22,
2016, 7, 1057. (g) Wang, Y.; Jiang, L.; Li, L.; Dai, J.; Xiong, D.;
229. (c) Kong, F.-D.; Ma, Q.-Y.; Huang, S.-Z.; Wang, P.; Wang, J.-
Shao, Z. Angew. Chem. Int. Ed. 2016, 55, 15142.
F.; Zhou, L.-M.; Yuan, J.-Z.; Dai, H.-F.; Zhao, Y.-X. J. Nat. Prod.
017, 80, 1039.
15) Wang, M.; Han, F.; Yuan, H. J.; Liu, Q. Chem. Commun. 2010, 46,
247.
(
5) (a) Zhuang, W.; Gathergood, N.; Hazell, R. G.; Jørgensen, K. A.
J. Org. Chem. 2001, 66, 1009. (b) Saaby, S.; Bayón, P.; Aburel, P.
S.; Jørgensen, K. A. J. Org. Chem. 2002, 67, 4352. (c) Shirakawa,
2
(
2
©
Georg Thieme Verlag Stuttgart · New York — Synlett 2017, 28, A–D