LETTER
Ring-Opening of meso-Aziridines with Amines
2515
Table 2 Cationic Iron-Catalyzed Ring-Opening Reactions of Aziridines with Anilines12 (continued)
FeCl2(mep) (5 mol%)
NHAr
Ar
R
AgSbF6 (10 mol%)
N
Ar + H
N
CH2Cl2, r.t.
NRAr
1
(1.2 equiv)
2–9
Entry
Aziridine
Aniline
Product
Time (h)
Yield (%)a
2
2
2
2
3
4
aniline
o-anisidine
N-methylaniline
7a
7b
7c
14
14
14
91
>99
>99
1
f
b
b
O
N
N
2
2
2
5
6
7
aniline
o-anisidine
N-methylaniline
8a
8b
8c
1
1
1
95
>99
>99
b
b
1g
1h
2
2
3
8
9
0
aniline
o-anisidine
N-methylaniline
9a
9b
9c
1
1
1
89
>99
>99
b
b
N
a
Isolated yields.
Determined by GC.
b
FeCl2[mep] (5 mol%)
AgSbF6 (10 mol%)
Rowland, G. B.; Rivera-Otero, E.; Antilla, J. C. J. Am.
Chem. Soc. 2007, 129, 12084. (d) Fukuta, Y.; Mita, T.;
Fukuda, N.; Kanai, M.; Shibasaki, M. J. Am. Chem. Soc.
2006, 128, 6312. (e) Mita, T.; Fujimori, I.; Wada, R.; Wen,
J.; Kanai, M.; Shibasaki, M. J. Am. Chem. Soc. 2005, 127,
NHBoc
O
N
+ Ar NH2
Ot-Bu
CH2Cl2, r.t.
NHAr
1
0
11a (Ar = Ph): 89%
11b (Ar = 2-MeOC6H4): 79%
11252.
(
3) For selected catalytic processes, see: (a) Hong, D.; Lin, X.;
Scheme 1 Iron-catalyzed ring-opening of N-Boc-aziridine 10
Zhu, Y.; Lei, M.; Wang, Y. Org. Lett. 2009, 11, 5678.
(
(
b) Wu, J.; Sun, X.; Li, Y. Eur. J. Org. Chem. 2005, 4271.
c) Bisai, A.; Bhanu Prasad, B. A.; Singh, V. K. Tetrahedron
In conclusion, we have discovered a new catalyst system
for the aminolysis of aziridines furnishing valuable 1,2-di-
amines in typically excellent yields. Generally, 5 mol% of
a dicationic iron complex was required for the reaction to
proceed to completion within short reaction time. The
large abundance and environmentally benign nature of the
iron catalyst makes this protocol particularly well suited
for large-scale applications. Work is being continued to
develop this process into a catalytic, enantioselective ring-
opening reaction of meso-aziridines with an optimal chiral
metal ligand.
Lett. 2005, 46, 7935. (d) Watson, I. D. G.; Yudin, A. K.
J. Org. Chem. 2003, 68, 5160. (e) Swamy, N. R.;
Venkateswarlu, Y. Synth. Commun. 2003, 33, 547.
(
f) Yadav, J. S.; Reddy, B. V. S.; Rao, K. V.; Raj, K. S.;
Prasad, A. R. Synthesis 2002, 1061. (g) Cossy, J.; Bellosta,
V.; Alauze, V.; Desmurs, J. R. Synthesis 2002, 2211.
(h) Hou, X.-L.; Fan, R.-H.; Dai, L.-X. J. Org. Chem. 2002,
6
7, 5295. (i) Chandrasekhar, M.; Sekar, G.; Singh, V. K.
Tetrahedron Lett. 2000, 41, 10079. (j) Sekar, G.; Singh,
V. K. J. Org. Chem. 1999, 64, 2537. For catalytic,
enantioselective protocols, see: (k) Arai, K.; Lucarini, S.;
Salter, M. S.; Ohta, K.; Yamashita, Y.; Kobayashi, S. J. Am.
Chem. Soc. 2007, 129, 8103. (l) Yu, R.; Yamashita, Y.;
Kobayashi, S. Adv. Synth. Catal. 2009, 351, 147. (m) Seki,
K.; Yu, R.; Yamazaki, Y.; Yamashita, Y.; Kobayashi, S.
Chem. Commun. 2009, 5722. (n) See ref. 9.
Acknowledgment
The Deutsche Forschungsgemeinschaft (Schn 441/9-1) is gratefully
acknowledged for generous financial support of this study. We
thank BASF, Siegfried, and Evonik for the donation of chemicals.
(
4) For selected catalytic processes, see: (a) Bhadra, S.; Adak,
L.; Samanta, S.; Maidul Islam, A. K. M.; Mukherjee, M.;
Ranu, B. C. J. Org. Chem. 2010, 75, 8533.
(
b) Bhanu Prasad, B. A.; Sanghi, R.; Singh, V. K.
References and Notes
Tetrahedron 2002, 58, 7355. (c) Hou, X.-L.; Fan, R.-H.;
Dai, L.-X. J. Org. Chem. 2002, 67, 5295. (d)Bhanu Prasad,
B. A.; Sekar, G.; Singh, V. K. Tetrahedron Lett. 2000, 41,
(
1) Selected reviews: (a) Schneider, C. Angew. Chem. Int. Ed.
009, 48, 2082. (b) Aziridines and Epoxides in Organic
Synthesis; Yudin, A. K., Ed.; Wiley-VCH: Weinheim,
006. (c) Pineschi, M. Eur. J. Org. Chem. 2006, 4979.
d) Hu, X. E. Tetrahedron 2004, 60, 2701. (e) McCoull,
2
4677.
(
5) For selected catalytic processes, see: (a) Zeng, F.; Alper, H.
Org. Lett. 2010, 12, 5567. (b) Yadav, J. S.; Reddy, B. V. S.;
Baishya, G.; Venkatram Reddy, P.; Narsaiah, A. V. Catal.
Commun. 2006, 7, 807. (c) Wu, J.; Sun, X.; Li, Y. Eur. J.
Org. Chem. 2005, 4271. (d) Yadav, J. S.; Subba Reddy,
B. V.; Baishya, G.; Reddy, P. V.; Harshavardhan, S. J.
Synthesis 2004, 1854. (e) Hou, X.-L.; Fan, R.-H.; Dai, L.-X.
J. Org. Chem. 2002, 67, 5295. (f) Wu, J.; Hou, X.-L.; Dai,
L.-X. J. Chem. Soc., Perkin Trans. 1 2001, 1314. For
2
(
W.; Davis, F. A. Synthesis 2000, 1347.
(
2) Most recent catalytic, enantioselective ring-opening
reactions: (a) Xu, Y.; Lin, L.; Kanai, M.; Matsunaga, S.;
Shibasaki, M. J. Am. Chem. Soc. 2011, 133, 5791. (b) Wu,
B.; Gallucci, J. C.; Parquette, J. R.; RajanBabu, T. V. Angew.
Chem. Int. Ed. 2009, 48, 1126. (c) Rowland, E. B.;
Synlett 2011, No. 17, 2513–2516 © Thieme Stuttgart · New York