COMMUNICATIONS
M. Lakshmi Kantam et al.
phenyliodinane (PhI¼NTs) as nitrene donor has been (0.186 g, 0.5 mmol) were added to this solution and the result-
ing mixture was stirred at room temperature for 1 h. After
demonstrated to afford the corresponding sulfimides
completion of the reaction, the catalyst was filtered off and
in good to excellent yields. In the presence of a chiral
the filtrate concentrated and purified by column chromatogra-
bis(oxazoline) as ligand, asymmetric induction occurs
phy (hexane/ethyl acetate, 20/80, v/v) to afford the pure prod-
uct as a white solid. Yield: 0.123 g (86%). HPLC (Daicel Chir-
alcel OJ column, 20% i-PrOH in hexane, flow rate 0.5 mL/
to afford the chiral sulfimides (up to 50% ee). The ionic
liquid containing the immobilized bis(oxazoline)-cop-
per catalyst can be reused for several cycles with consis-
tent activity and enantioselectivity.
min): t ¼31.4 (minor), t ¼49.8 (major).
R
R
Typical Procedure for Asymmetric Sulfimidation using
Experimental Section
Cu(acac) Immobilized in Ionic Liquid
2
To ionic liquid (1 mL) were added Cu(acac)2 (0.006 g,
0
0
.023 mmol) and 4,4’-disubstituted bis(oxazoline) 1b (0.016 g,
.047 mmol) and the mixture was stirred for 1 h. Methyl p-tolyl
Typical Procedure for Sulfimidation using MC-
Cu(acac)2
sulfide (0.069 g, 0.5 mmol) and PhI¼NTs (0.186 g, 0.5 mmol)
were then added to this solution and the resulting mixture
was stirred at room temperature for 15 min. After completion
of the reaction, the product was extracted with 1:4 hexane/eth-
yl acetate by simple decantation and purified by column chro-
matography on silica gel (hexane/ethyl acetate, 20/80 v/v as an
eluent) to afford the pure product as a white solid. Yield: 0.13 g
To acetonitrile (3 mL) were added MC-Cu(acac) (0.075 g,
2
0
.028 mmol), methyl phenyl sulfide (0.062 g, 0.5 mmol) and
PhI¼NTs (0.186 g, 0.5 mmol) and the reaction mixture was stir-
red at room temperature for the time shown in Table 1. The re-
action was monitored by the disappearance of PhI¼NTs from
the reaction mixture. After completion of the reaction, the cat-
alyst was filtered off and the filtrate concentrated and purified
by column chromatography (hexane/ethyl acetate, 20/80, v/v)
to afford the pure product as a white solid. Yield: 0.126 g
(
85%). HPLC (Daicel Chiralcel OJ column, 20% i-PrOH in
hexane, flow rate 0.5 mL/min): t ¼30.5 (minor), t ¼33.5 (ma-
R
R
jor).
[
28]
1
(
2
(
1
86%); mp 1328C (lit : 131–1328C). H NMR (CDCl3,
00 MHz): d¼2.34 (s, 3H, CH ) 2.81 (s, 3H, CH ) 7.12–7.71
3
3
m, 9H, ArꢀH); IR (KBr): n¼3030, 2928, 1597, 1447, 1279,
ꢀ
1
142, 1090, 962, 756, 662, 575 cm ; anal. calcd. for
Acknowledgements
C H NO S : C 57.31, H 5.15, N 4.77, S 21.84; found: C 57.28,
14
15
2 2
H 5.16, N 4.67, S 21.55.
B. K., V. N. and Y. H. thank the Council of Scientific and Indus-
trial Research, India, for their fellowships. S. K. D. is an institute
research fellow of IIT, Guwahati.
Typical Procedure for Sulfimidation using Cu(acac)2
Immobilized in Ionic Liquid
To a solution of Cu(acac) (0.006 g, 0.023 mmol) in ionic liquid
2
References
(
1 mL) were added methyl p-tolyl sulfide (0.069 g, 0.5 mmol)
and PhI¼NTs (0.186 g, 0.5 mmol) and the reaction mixture
was stirred at room temperature. The reaction was monitored
[1] a) I. Fernandez, N. Khiar, Chem. Rev. 2003, 103, 3651;
b) K. Hiroi, Y. Suzuki, I. Abe, R. Kawagishi, Tetrahedron
2000, 56, 4701; c) H. Cotton, T. Elebring, M. Larsson, L.
Li, H. Sorensen, S. von Unge, Tetrahedron: Asymmetry
2000, 11, 3819. d) M. Tanaka, H. Yamazaki, H. Hakusui,
N. Nakamichi, H. Sekino, Chirality 1997, 9, 17.
[2] C. P. Baird, P. C. Taylor, J. Chem. Soc. Chem. Commun.
1995, 893.
by the disappearance of PhI¼NTs. After completion of the re-
action, the product was extracted with 1:4 hexane/ethyl ace-
tate by simple decantation and purified by column chromatog-
raphy on silica gel (hexane/ethyl acetate, 20/80 v/v as eluent) to
afford the pure product as a white solid. Yield: 0.131 g (86%);
[29]
1
mp 1258C (lit : 125–1268C). H NMR (CDCl , 200 MHz):
3
d¼2.35 (s, 3H, CH ) 2.4 (s, 3H, CH ) 2.81 (s, 3H, CH ) 7.16
3
3
3
(
(
(
9
d, 2H, J¼8.1 Hz, ArꢀH) 7.29 (d, 2H, J¼8.1 Hz ArꢀH) 7.57
d, 2H, J¼8.3 Hz, ArꢀH), 7.73 (d, 2H, J¼8.3 Hz, Ar-H); IR
KBr): n¼3032, 2922, 1597, 1495, 1406, 1275, 1136, 1088, 997,
[
3] D. J. Cram, J. Day, D. R. Rayner, D. M. von Schriltz, D. J.
Duchamp, D. C. Garwood, J. Am. Chem. Soc. 1970, 92,
7
369.
ꢀ
1
51, 814, 754, 664, 571 cm ; anal. calcd. for C H NO S : C
15 17 2 2
[
[
[
[
4] R. Annunziata, M. Cinquini, S. Colonna, F. Cozzi, J.
Chem. Soc. Perkin Trans. 1 1981, 3118.
5] D. A. Evans, M. M. Faul, M. T. Bilodeau, B. A. Ander-
son, D. M. Barnes, J. Am. Chem. Soc. 1993, 115, 5328.
6] H. Takada, Y. Nishibayashi, K. Ohe, S. Uemura, J. Chem.
Soc. Chem. Commun. 1996, 931.
7] H. Takada, Y. Nishibayashi, K. Ohe, S. Uemura, C. P.
Baird, T. J. Sparey, P. C. Taylor, J. Org. Chem. 1997, 62,
6512.
58.60, H 5.57, N 4.56, S 20.80; found: C 58.50, H 5.47, N 4.58,
S 20.20.
Typical Procedure for Asymmetric Sulfimidation using
MC-Cu(acac)2
To acetonitrile (3 mL) were added MC-Cu(acac) (0.075 g,
2
0
(
.028 mmol), and 4,4’-disubstituted bis(oxazoline) 1b
0.019 g, 0.056 mmol) and the mixture was stirred for 1 h.
Then methyl phenyl sulfide (0.062 g, 0.5 mmol) and PhI¼NTs
[8] Y. Miyake, H. Takada, K. Ohe, S. Uemura, J. Chem. Soc.
Perkin Trans. 1 1998, 2373.
644
ꢀ 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
asc.wiley-vch.de
Adv. Synth. Catal. 2005, 347, 641–645