Please do not adjust margins
Green Chemistry
Page 4 of 6
DOI: 10.1039/C7GC02682J
COMMUNICATION
Journal Name
Conflicts of interest
There are no conflicts of interest to declare.
Acknowledgements
This study was supported by the National Natural Science
Foundation of China (21502090 and 21522604), Natural
Science Foundation of Jiangsu Province (BK20150942 and
BK20150031), and the National Key Research and
Development Program of China (2016YFB0301501).
Scheme 2 Control experiments.
Notes and references
1
2
K. J. Ivey, Am. J. Med., 1988, 84, 41-48.
A. Lanas, E. Bajador, P. Serrano, J. Fuentes, S. Carreño, J.
Guardia, M. Sanz, M. Montoro and R. Sáinz, N. Engl. J. Med.,
2000, 343, 834-839.
3
4
J. L. Burgaud, E. Ongini and P. Del Soldato, Ann. N. Y. Acad.
Sci., 2002, 962, 360-371.
I. V. Serkov and V. V. Bezuglov, Dokl. Akad. Nauk., 2009, 425
777-779.
,
5
6
7
8
9
J. Abrams, Am. Heart J., 1985, 110, 216-224.
R. M. Gunnar and C. Fisch, Circulation, 1990, 82, 664-707.
J. O. Parker, N. Eng. J. Med., 1987, 316, 1635-1642.
C. R. Conti, Am. J. Cardiol., 1987, 60, 31-34.
Y. Bi, X. Yang, T. T. Zhang, Z. Y. Liu, X. C. Zhang, J. Lu, K. G.
Cheng, J. Y. Xu, H. B. Wang, G. Y. Lv, P. J. Lewis, Q. G. Meng
and C. Ma, Eur. J. Med. Chem., 2015, 101, 71-80.
Scheme 3 Plausible mechanism.
However, the desired product was not detected. This result
implies that the esterification process did not involve this
intermediate.
10 R. Boschan, R. T. Merrow and R. W. Van Dohla, Chem. Rev.,
1955, 25, 485-510.
On the basis of the above results and previous literature
11 E. H. White and W. R. Feldman, J. Am. Chem. Soc., 1957, 79
5832-5833.
,
reports31-33,38
a plausible mechanistic pathway for the
formation of 3a is proposed (Scheme 3). Initially, ONOO. is
generated in situ from TBN with O2 under thermal conditions.
Then 2-aryl oxazoline 4a is ring-opened by the nucleophile
12 P. Golding, R. W. Millar, N. C. Paul and D. H. Richards,
Tetrahedron Lett., 1988, 29, 2731-2734.
13 A. McKillop and M. E. Ford, Tetrahedron, 1974, 30, 2467-
2475.
14 M. C. Breschi, V. Calderone, M. Digiacomo, M. Macchia, A.
Martelli, E. Martinotti, F. Minutolo, S. Rapposelli, A. Rossello,
L. Testai and A. Balsamo, J. Med. Chem., 2006, 49, 2628-
2639.
15 M. Botta, E. Distrutti, A. Mencarelli, M. C. Parlato, F. Raffi, S.
Cibrina and S. Fiorucci, ChemMedChem, 2008, 3, 1580-1588.
ONOO.. Next, intermediate
A is generated via intermolecular
single-electron transfer (SET) between the 2-aryl oxazoline
moiety and ONOO.. Finally, the desired product 5a is obtained
through hydrogen abstraction of the sp3 C–H bond in 1,4-
dioxane, and radical intermediate
B
is generated. Radical
reacts
transmission is terminated when radical intermediate
B
16 A. Mukai, T. Fukai, M. Matsumoto, J. Ishikawa, Y. Hoshino, K.
Yazawa, K. Harada and Y. Mikami, J. Antibiot., 2006, 59, 366-
369.
with the tert-butoxy radical to form byproduct C.
17 J. Suzuki, T. Ishida, I. Shibuya and K. Toda, J. Pestic. Sci., 2001,
26, 215-223.
18 T. G. Gant and A. I. Meyers, Tetrahedron, 1994, 50, 2297-
2360.
Conclusions
In conclusion, we have developed a novel and efficient method
for the synthesis of β-nitrate ester carboxamides through the
ring-opening of 2-oxazolines. The esterification reaction with
2-substituted oxazolines tolerates a wide range of functional
groups, and the reaction proceeds smoothly to provide the
corresponding products in excellent yields. The utilization of
non-corrosive TBN and easily available oxygen gives this
method several advantages over traditional procedures
because it avoids the use of highly corrosive H2SO4/HNO3 or
N2O5 as reagents. This reaction system is environmentally
friendly, shows high functional group tolerance, gives fast
access to pharmaceuticals such as nicorandil, and can be easily
scaled up.
19 J. A. Frump, Chem. Rev., 1971, 71, 483-505.
20 J. S. Johnson and D. A. Evans, Acc. Chem. Res., 2000, 33, 325-
335.
21 M. Gómez, G. Muller and M. Rocamora, Coord. Chem. Rev.,
1999, 193-195, 769-835.
22 D. S. Laitar, J. W. Kramer, B. T. Whiting, E. B. Lobkovsky and
G. W. Coates, Chem. Commun., 2009, 38, 5704-5706.
23 B. Gutmann, J. Roduit, D. Roberge and C. O. Kappe, Chem.
Eur. J., 2011, 17, 13146-13150.
24 V. R. de la Rosa, S. Tempelaar, P. Dubois, R. Hoogenboom
and L. Mespouille, Poly. Chem., 2016, 7, 1559-1568.
25 J. Banoub, P. Boullanger and D. Lafont, Chem. Rev., 1992, 92
1167-1195.
,
4 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins