1066
L. Wang et al.
LETTER
(5) Wang, L.; Zhang, Y. Tetrahedron 1998, 54, 11129; Lautens,
M.; Ren, Y. J. Org. Chem. 1996, 61, 2210.
(6) Wang, L.; Zhang, Y. Tetraheddron, Lett. 1998, 39, 5257.
(7) Hou, Z.; Fujiwara. Y.; Taniguchi, H. J. Org. Chem. 1988, 53,
3118.
(8) Tafesh, A. M.; Weiguny, J. Chem. Rev. 1996, 96, 2035.
(9) Alper, H.; Amaratunga, S. Tetrahedron Lett. 1980, 21, 2603.
(10) Suzuki, H.; Hanazaki, Y. Chem. Lett. 1986, 549.
(11) Fischer, B.; Sheihet, L. J. Org. Chem. 1998, 63, 393.
(12) Boothroyd, S. R.; Kerr, M. A. Tetrahedron Lett. 1995, 36,
2411.
In conclusion, we have demonstrated that Sm-I2 (trace)/
THF-NH4Cl (aq.) system can be used for the selective re-
duction of aromatic nitro compounds to the corresponding
aromatic amines. The notable advantages of this reaction
are its simplicity, mild reaction conditions and good
yields. It provides a new way for using metallic samarium
in organic synthesis.
Acknowledgement
(13) Upadhya, T. T.; Katdare, S. P.; Sabde, D. P.; Ramaswamy, V.;
Sudalai, A. J. Chem. Soc., Chem. Commun. 1997, 1119.
(14) Kumbhar, P. S.; Sanchez-Valente, J.; Figueras, F.
Tetrahedron Lett. 1998, 39, 2573.
We thank the National Natural Science Foundation of China (Pro-
ject No. 29872010), the NSF of Zhejiang Province, China and the
Laboratory of Organometallic Chemistry, Shanghai Institute of Or-
ganic Chemistry, Chinese Academy of Sciences for financial sup-
ports.
(15) Moody, C. J.; Pitts, M. R. Synlett 1998, 1028.
(16) Typical procedure: Under an inert atmosphere of nitrogen,
metallic samarium powder (0.6 g, 4.0 mmol) and aromatic
nitro compound (1.0 mmol) were placed in a round-bottomed
flask. Then THF (5 mL), a small grain of iodine and NH4Cl
(aq., 0.5 mL) were added successively to it. The reaction
mixture was stirred for the time indicated in Table at room
temperature. The reaction was then quenched by the addition
of HCl (1 mol/L, 2 mL). The mixture was extracted with ether
(25 mL x 2). The combined organic layer was washed with
brine, dried over magnesium sulfate, and concentrated. The
product was isolated by preparative TLC on silica gel eluting
with cyclohexane-ethyl acetate (3:1).
References and Notes
(1) Kagan, H. B.; Namy, J. L. Tetrahedron 1986, 42, 6573;
Molander, G. A. Chem. Rev. 1992, 92, 29; Molander, G. A.
Organic Reaction 1994, 46, 211; Molander, G. A.; Harris, C.
R. Chem. Rev. 1996, 96, 307.
(2) Yanada, R.; Negoro, N.; Yanada, K.; Fujita, T. Tetrahedron
Lett. 1997, 38, 3271; Yanada, R.; Negoro, N.; Yanada, K.;
Fujita, T. Tetrahedron Lett. 1996, 37, 9313; Lautens, M.;
Delanghe, P. H. J. Org. Chem. 1995, 60, 2474.
(3) Hou, Z.; Takamine, K.; Fujiwara, Y. Chem. Lett. 1987, 305.
(4) Molander, G. A.; Harring, L. S. J. Org. Chem. 1989, 54, 3525;
Clive, D, L. J.; Daigneault, S. J. Org. Chem. 1991, 56, 3801.
Article Identifier:
1437-2096,E;1999,0,07,1065,1066,ftx,en;Y09499ST.pdf
Synlett 1999, No. 07, 1065–1066 ISSN 0936-5214 © Thieme Stuttgart · New York