10.1002/chem.201604802
Chemistry - A European Journal
COMMUNICATION
J. Linderman, K. Lorenz, J. Manley, B. A. Pearlman, A. Wells, A. Zaks,
T. Y. Zhang, Green Chem. 2007, 9, 411–420.
In conclusion we have developed an efficient, very mild and
chemoselective reduction of tertiary amides that involves borinic
acid 3. Mechanistic studies suggest the involvement of amine-
borane complex 10. This reaction features the use of an easily
synthesized catalyst[10] with loading as low as 1 mol% and
reaction temperature as low as 0 °C being documented. It is
worthy to note that this new methodology is especially user
friendly since reactions are performed at room temperature using
standard equipment and solvent-free in most cases. Additionally,
no stoichiometric activation of the amide is required.[19] We
anticipate that this methodology will become a strong alternative
to metal and perfluoroborane based catalysts that will facilitate the
production of valuable functionalized amines from the
corresponding amides.[20]
[3]
[4]
R. J. P. Corriu, J. J. E. Moreau, M. Pataud-Sat, J. Organomet. Chem.
1982, 228, 301–308.
a) D. Addis, S. Das, K. Junge, M. Beller, Angew. Chem. Int. Ed. 2011,
50, 6004–6011; Angew. Chem. 2011, 123, 6128–6135. For selected
recent contribution see b) I. Sorribes, K. Junge, M. Beller, J. Am. Chem.
Soc. 2014, 136, 14314–14319; c) O. O. Kovalenko, A. Volkov, H.
Adolfsson, Org. Lett. 2015, 17, 446–449; d) N. Sakai, M. Takeoka, T.
Kumaki, H. Asano, T. Konakahara, Y. Ogiwara, Tetrahedron Lett. 2015,
56, 6448–6451; e) A. Volkov, F. Tinnis, T. Slagbrand, I. Pershagen, H.
Adolfsson, Chem. Commun. 2014, 50, 14508–14511; For a related
review about main group element catalyzed reduction of unsaturated
bonds see: K. Revunova, G. I. Nikonov, Dalton Trans. 2015, 44, 840–
866.
[5]
F. Tinnis, A. Volkov, T. Slagbrand, H. Adolfsson, Angew. Chem. Int. Ed.
2016, 55, 4562–4566; Angew. Chem. 2016, 128, 4638–4642.
T. Meixuan, Y. Zhang, Tetrahedron Lett. 2009, 50, 4912–4915.
E. Blondiaux, T. Cantat, Chem. Commun. 2014, 50, 9349–9352.
R. C. Chadwick, V. Kardelis, P. Lim, A. Adronov, J. Org. Chem. 2014, 79,
7728–7733.
[6]
[7]
[8]
Experimental Section
To an oven dried sealed tube under argon atmosphere was added 2-
chlorophenylborinic acid 3 (12.5 mg, 0.05 mmol, 0.05 equiv) followed by
the amide (1 mmol). Then, phenylsilane (0.295 mL, 2.4 mmol, 2.4 equiv)
was added under argon atmosphere. The resulting mixture was stirred
during 12 hours at room temperature. Thereafter volatiles were evaporated
under vacuum. Purification by flash column chromatography afforded the
desired amines.
[9]
Y. Li, A. Jesus, M. de La Torre, K. Grabow, U. Bentrup, K. Junge, S.
Zhou, A. Bruckner, M. Beller, Angew, Chem. Int. Ed. 2013, 52, 11577–
11580; Angew. Chem. 2013, 125, 11791–11794.
[10] a) T. Mohy El Dine, J. Rouden, J. Blanchet, Chem. Commun, 2015, 51,
16084–16087; b) T. Mohy El Dine, D. Evans, J. Rouden, J. Blanchet,
Chem. Eur. J, 2016, 22, 5894–5898.
[11] See supporting information for full details.
[12] V. Gevorgyan, M. Rubin, S. Benson, J.-X. Liu, Y. Yamamoto, J. Org.
Chem. 2000, 65, 6179–6186.
[13] J. M. Blackwell, E.R. Sonmor, T. Scoccitti, W.E. Piers, Org Lett, 2000,
3921–3921.
Acknowledgements
[14] a) A. Y. Houghton, J. Hurnalainen, A. Mansikkamaki, W.E. Piers, H.
Tuononen, Nature Chem. 2014, 6, 983–988; b) S. Rendler, M. Oestreich,
Angew. Chem. Int. Ed. 2008, 47, 5997–6000; Angew. Chem. 2008, 120,
6086–6089 and references cited therein.
The authors thank the CNRS, Normandie université, Labex
Synorg (ANR-11-LABX-0029) for AC fellowship, the Conseil
Régional de Normandie and the European FEDER fundings for
financial support. TMED gratefully acknowledge ANR (ANR-12-
JS07-0013 NeoACat) for fellowship.
[15] For isolated examples of amide reduction involving super hydride
LiHBEt3 as catalyst see: M. G. Manas, L. S. Sharninghausen, D. Balcells,
R. H. Crabtree, New J. Chem. 2014, 38, 1694–1700; See supplementary
information scheme S1 for details.
Keywords: reduction · organocatalysis· borinic acid· amide
[16] J. A. Soderquist, H. C. Brown, J. Org. Chem. 1980, 45, 3571–3578.
[17] V. Gevorgyan, M. Rubin, J.-X. Liu, Y. Yamamoto, J. Org. Chem. 2001,
66, 1672–1675. And references cited therein.
[1]
a) Reductions in Organic Chemistry; M. Hudlicky, Ed.; John Wiley &
Sons: New York, 1984; b) Comprehensive Organic Synthesis; B. M.
Trost, I. Fleming, Eds.; Pergamon: Oxford, U.K., 1991; Vol. 8; c)
Reductions by the Alumino- and Borohydrides in Organic Synthesis; J.
Seyden-Penne, Ed.; Wiley-VCH: New York, 1997; For related recent
report see d) N. L. Lampland, M. Hovey, D. Mukherjee, A. D. Sadow,
ACS Catal. 2015, 5, 4219–4226.
[18] Z. M. Heiden, A. P. Lathem, Organometallics 2015, 34, 1818–1827.
[19] For a recent room temperature hydrosilylation of amine using B(C6F5)3
and Tf2O as stoichiometric activator see P.-Q. Huang, Q.-W. Lang, Y.-R.
Wang, J. Org. Chem. 2016, 81, 4235–4243.
[20] During the preparation of this manuscript a triphenylborane catalyzed
reduction of amides appeared: D. Mukherjee, S. Shirase, K. Mashima, J.
Okuda, Angew. Chem. Int. Ed. 2016, 55, 13326–13329; Angew. Chem.
2016, 128, 13520–13523.
[2]
a) Modern Amination Methods (Ed.: A. Ricci), Wiley, New York, 2000; b)
Modern Reduction Methods (Ed P. G Andersson, I. J. Munslow, Wiley-
VCH, New York, 2008; c) H. A. Wittcoff, B. G. Reuben, J. S. Plotkin,
Industrial Organic Chemicals, 2nd ed.; Wiley: New York, 2004; d) D. J. C.
Constable, P. J. Dunn, J. D. Hayler, G. R. Humphrey, J. J. L. Leazer, R.
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