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Chemical Science
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ARTICLE
T. Furuya, A. S. Kamlet and T. Ritter, NDaOtuI:r1e0,.12003191/C, 64S7C30,3410790A;
(c) X. Yang, T. Wu, R. J. Phipps and F. D. Toste, Chem. Rev.,
2015, 115, 826; (d) R. Britton and B. Kang, Nat. Prod. Rep.,
2013, 30, 227; (e) A. M. R. Smith and K. K. (Mimi) Hii, Chem.
Rev. 2011, 111, 1637; (f) S. Lectard, Y. Hamashima and M.
Sodeoka, Adv. Synth. Catal., 2010, 352, 2708; (g) J.-H. Lin and
J.-C. Xiao, Tetrahedron Lett., 2014, 55, 6147; (h) J.Wang,
M.S‚ánchez-Rosollo, J. L. Acena, C. del Pozo, A. E.
Sorochinsky, S. Fustero, V. A. Soloshonok and H. Liu, Chem.
Rev., 2014, 114, 2432. (i) V. Bizet, T. Besset, J.-A. Ma and D.
Cahard, Current Topics in Medicinal Chemistry, 2014, 14, 901.
For leading examples on metal Lewis acid catalysis, see: (a) L.
TS-R would be mainly disfavoured by electrostatic repulsion
not by steric effect. By AIM analysis, we could also identified
an attractive C-H---F interaction between the tert-butyl group
of amine catalyst and Figure 1b, which may also contribute in
facilitating the Si-facial attack in TS-S.14
Conclusions
In summary, we have presented herein a reagent-controlled
enantioselectivity switch in organocatalytic asymmetric
5
fluorination of β-ketocarbonyls.
A simple swap of the
Hintermann and A. Togni, Angew. Chem. Int. Ed., 2000, 39
,
fluorination reagent switched enantioselectivity with good
reactivity and enantiomeric excess in both cases. Mechanistic
studies revealed dual H-bonding and electrostatic
stereocontrolling modes for a single chiral primary amine
catalyst. Further explorations of switchable enantioselectivity
in other reactions are currently underway in our laboratory.
4359; (b) Y. Hamashima, K. Yagi, H. Takano, L. Tama´s and M.
Sodeoka, J. Am. Chem. Soc., 2002, 124, 14530. (c) N. Shibata,
J. Kohno, K. Takai, T. Ishimaru, S. Nakamura, T. Toru and S.
Kanemasa, Angew. Chem. Int. Ed., 2005, 44, 4204. (d) A.
Narayama, K. Shibatomi, Y. Soga, T. Muto and S. Iwasa,
Synlett, 2013, 24, 375.
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7
8
9
For organocatalytic fluorination of
β
-Ketocarbonyls, see: (a)
, 545; (b) X. Wang,
D. Y. Kim and E. J. Park, Org. Lett., 2002,
4
Q. Lan, S. Shirakawa and K. Maruoka, Chem. Commun., 2010,
46, 321; (c) J. Xu, Y. Hu, D. Huang, K.-H. Wang, C. Xu and T.
Niu, Adv. Synth. Catal., 2012, 354, 515.
(a) M. Marigo, D. Fielenbach, A. Braunton, A. Kjærsgaard and
K. A. Jørgensen, Angew. Chem. Int. Ed., 2005, 44, 3703; (b) D.
D. Steiner, N. Mase and C. F. Barbas, Angew. Chem, Int. Ed.,
2005, 44, 3706; (c) T. D. Beeson and D. W. C. MacMillan, J.
Am. Chem. Soc., 2005, 127, 8826.
Acknowledgements
The project was supported by Ministry of Science and
Technology (2012CB821600), the Natural Science Foundation
of China, and the Chinese Academy of Sciences.
(a) S. Brandes, B. Niess, M. Bella, A. Prieto, J. Overgaard and
K. A. Jørgensen, Chem. Eur. J., 2006, 12, 6039; (b) M. R.
Witten and E. N. Jacobsen, Org. Lett., 2015, 17, 2772; (c) K.
Shibatomi, K. Kitahara, T. Okimi, Y. Abe and S. Iwasa, Chem.
Notes and references
1
For recent reviews on switching selectivity, see: (a) G. Zanoni,
F. Castronovo, M. Franzin, G. Vidari and E. Giannini, Chem.
Soc. Rev., 2003, 32, 115; (b) Comprehensive Asymmetric
Catalysis (Eds.: E. N. Jacobsen, A. Pfaltz and H. Yamamoto),
Springer, Berlin, 1999; (c) Catalytic Asymmetric Synthesis
(Ed.: I. Ojima), Wiley-VCH, New York, 2000; (d) V. Blanco, D.
Sci., 2016, 7, 1388-1392.
(a) P. Kwiatkowski, T. D. Beeson, J. C. Conrad and D. W. C.
MacMillan, J. Am. Chem. Soc., 2011, 133, 1738; (b) Y. Lam
and K. N. Houk, J. Am. Chem. Soc., 2014, 136, 9556.
A. Leigh and V. Marcos, Chem. Soc. Rev., 2015, 44, 5341; (e) 10 X. Yang, R. J. Phipps and F. D. Toste, J. Am. Chem. Soc., 2014,
X. Jiang and R. Wang, Chem. Rev., 2013, 113, 5515; (f) T. 136, 5225.
Tanaka and M. Hayashi, Synthesis, 2008, 3361; (g) M. Bartók, 11 (a) L.-S. Zheng, Y.-L. Wei, K.-Z. Jiang, Y. Deng, Z.-J. Zheng and
Chem. Rev., 2010, 110, 1663; (h) J. Escorihuela, M. I. Burguete
and S. V. Luis, Chem. Soc. Rev., 2013, 42, 5595.
For recent examples, see: (a) J. Wang and B. L. Feringa,
Science, 2011, 331, 1429; (b) S. Mortezaei, N. R. Catarineu
and J. W. Canary, J. Am. Chem. Soc., 2012, 134, 8054; (c) S. A. 12 L. Zhang, N. Fu and S. Luo, Acc. Chem. Res., 2015, 48, 986.
Moteki, J. Han, S. Arimitsu, M. Akakura, K. Nakayama and K. 13 The intramolecular F-attack with secondary NH-F species
L-W. Xu, Adv. Synth. Catal., 2014, 356, 3769; (b) S. J. Kwon
and D. Y. Kim, Journal of Fluorine Chemistry, 2015, 180, 201;
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Sodeoka, Tetrahedron, 2015, 71, 6594.
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Maruoka, Angew. Chem. Int. Ed., 2012, 51, 1187; (d) J. Lv, Y.
Qin, J. Cheng and S. Luo, Acta Chim. Sinica., 2014, 72, 809;
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X. Feng, Chem. Commun., 2015, 51, 8432; (f) N. Shibata, T.
(see ref. 9b), in situ transferred from fluorination reagent to
the aminocatalyst, though not completely excluded, may not
be applicable in our cases. First, there is no such precedence
on fluorination with NH-F species. In addition, even if F-
transfer did occur, facile proton release instead of F-attack
might be the dominant pathway, leading to an unreactive
neutral -N-F species or even poison of catalyst. Experimentally,
we did not detect such species by in-situ ESI-MS in both cases.
Ishimaru, T. Nagai, J. Kohno and T. Toru, Synlett, 2004, 10
,
1703.
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4
For organocatalytic enantioselectivity switch, see: (a) Y.
Sohtome, S. Tanaka, K. Takada, T. Yamaguchi and K.
Nagasawa, Angew. Chem. Int. Ed., 2010, 49, 9254; (b) A. 14 In TS-S, a short C-H…F distance was found with 2.44 Å. Atoms
Garzan, A. Jaganathan, N. Salehi Marzijarani, R. Yousefi, D. C.
Whitehead, J. E. Jackson and B. Borhan, Chem. Eur. J., 2013,
19, 9015; (c) S. A. Moteki, J. Han, S. Arimitsu, M. Akakura, K.
in Molecules (AIM) analysis at the bond critical point
suggested a weak interaction between H and F where the
electron denstity (ρ) is 0.0089 au and the Laplacian values
(Δρ2) is 0.037 au. These values indicate that a weak C-H…F
interaction is present. For a review on C-H…F-C interaction,
Nakayama and K. Maruoka, Angew. Chem. Int. Ed., 2012, 51
,
1187; (d) Y. Fukata, K. Asano and S. Matsubara, J. Am. Chem.
Soc., 2013, 135, 12160.
For recent reviews on asymmetric fluorination reactions, see:
(a) P. A. Champagne, J. Desroches, J.-D. Hamel, M.
see: C.-C. Liu and M. C. W. Chan, Acc. Chem. Res., 2015, 48
,
1580.
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