(0.004 mmol), 1,4-dioxane (20 mL), and water (0.36 mL). The
reaction mixture was vigorously stirred at 100 ◦C under Ar for
6 h. After the reaction was complete, the catalyst was removed
by filtration, and the filtrate was evaporated. The crude product
was purified by distillation, thus affording 3a as a colorless oil
(70% isolated yield).
F. Sels, D. E. De Vos and P. A. Jacobs, Catal. Rev. Sci. Eng., 2001,
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Catal., 2004, 221, 62; (h) B. F. Sels, D. E. De Vos and P. A. Jacobs,
Angew. Chem., Int. Ed., 2005, 44, 310.
3 Our reports on hydrotalcite catalysis: (a) K. Yamaguchi, K. Mori,
T. Mizugaki, K. Ebitani and K. Kaneda, J. Org. Chem., 2000, 65,
6897; (b) K. Motokura, T. Mizugaki, K. Ebitani and K. Kaneda,
Tetrahedron Lett., 2004, 45, 6029; (c) K. Motokura, D. Nishimura,
K. Mori, T. Mizugaki, K. Ebitani and K. Kaneda, J. Am. Chem. Soc.,
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Ebitani, K. Motokura, T. Mizugaki and K. Kaneda, Angew. Chem.,
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Mizugaki, K. Ebitani, K. Jitsukawa and K. Kaneda, Chem.–Eur. J.,
2006, 12, 8228.
1,4-Addition of arylboronic acids to electron-deficient olefins in
water
Into a pyrex glass reactor were combined 1a (1.0 mmol),
2a (1.5 mmol), Rh/HT (0.06 g, Rh: 0.012 mmol), 1,5-cod
(0.012 mmol), and water (2.0 mL). The reaction mixture was
vigorously stirred at 100 ◦C under Ar for 4 h. After the
reaction was complete, the catalyst was removed by filtration,
and the filtrate was extracted with ethyl acetate. The organic
layers were combined and concentrated by evaporation to give
the crude product, which was purified by silica gel column
chromatography (n-hexane/ethyl acetate, 9 : 1), thus affording
3a as a colorless oil (90% isolated yield).
4 M. Sasaki, H. Hayashi and N. Miyaura, Organometallics, 1997, 16,
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5 (a) Y. Takaya, M. Ogasawara, T. Hayashi, M. Sasaki and N. Miyaura,
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Nishikata, T. Iyama, H. Tachikawa, Y. Kobayashi, Y. Yamamoto and
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45, 3353; (k) S. So¨rgel, N. Tokunaga, K. Sasaki, K. Okamoto and T.
Hayashi, Org. Lett., 2008, 10, 589.
6 Heterogeneous Rh catalysts for 1,4-addition: (a) Y. Uozumi and M.
Nakazono, Adv. Synth. Catal., 2002, 344, 274; (b) Y. Otomaru, T.
Senda and T. Hayashi, Org. Lett., 2004, 6, 3357; (c) M. L. Kantam,
V. B. Subrahmanyam, K. B. S. Kumar, G. T. Venkanna and B.
Sreedhar, Helv. Chim. Acta, 2008, 91, 1947; (d) F. Neat, M. Besnea,
V. G. Komvokis, J.-P. Geneˆt, V. Michelet, K. S. Triantafyllidis and
V. I . P aˆrvulescu, Catal. Today, 2008, 139, 161; (e) P. Handa, K.
Holmberg, M. Sauthier, Y. Castanet and A. Mortreux, Microporous
Mesoporous Mater., 2008, 116, 424; (f) P. Handa, T. Witula, P. Reis
and K. Holmberg, ARKIVOC, 2008, vi, 107; (g) R. Jana and J. A.
Tungem, Org. Lett., 2009, 11, 971; (h) M. Sauthier, N. Lamotte, J.
Dheur and Y. Castanet, New J. Chem., 2009, 33, 969.
One-pot three-component synthesis
A mixture of benzaldehyde (1.0 mmol), ethyl cyanoacetate
(1.0 mmol), Rh/HT (0.060 g, Rh: 0.012 mmol), 1,5-cod
(0.012 mmol), and 1,4-dioxane (2.0 mL) was vigorously stirred
at 100 ◦C under Ar for 8 h. Then, 2a (1.5 mmol) was added to the
same flask, and allowed to further react at 100 ◦C under Ar for
12 h. After the reaction, the catalyst was separated by filtration.
The filtrate was evaporated and the crude product was purified
by silica gel column chromatography (n-hexane/ethyl acetate,
9 : 1) to afford a pure ethyl 2-cyano-3,3-diphenylpropionate (88%
isolated yield).
Acknowledgements
This work was supported by a Grant-in-Aid for Scientific Re-
search on Priority Areas (No.18065016, “Chemistry of Concerto
Catalysis”) and No. 20360364 from the Ministry of Education,
Culture, Sports, Science and Technology (Japan). Some of the
experiments were carried out at a facility in the Photon Factory
(KEK-PF, Proposal No. 2009G069). We are also grateful to
‘Gas-Hydrate Analyzing System’ in the Dept. Mater. Eng. Sci.,
Grad. Sch. Eng. Sci., Osaka University for XRD experiments.
7 N. Fujita, K. Motokura, K. Mori, T. Mizugaki, K. Ebitani, K.
Jitsukawa and K. Kaneda, Tetrahedron Lett., 2006, 47, 5083.
8 H. Fujiwara, Y. Ogasawara, K. Yamaguchi and N. Mizuno, Angew.
Chem., Int. Ed., 2007, 46, 5202.
9 Homogeneous Rh complexes with diene ligands have also been
reported as high-performance catalysts for the 1,4-addition reaction,
see reference 5c–f. The weak electron-donating effect of 1,5-COD
ligand on a Rh center may accelerate the transmetalation or the
addition step of phenyl group in Scheme 1.
10 For Rh-catalyzed 1,2-addition reaction of organoboron reagents, see:
references 5h–j.
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2422 | Green Chem., 2011, 13, 2416–2422
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