Chiral (OC)Ru(salen)-catalyzed tandem sulfimidation and [2,3]sigmatropic rearrangement: Asymmetric C-N bond formation

Article abstract of DOI:10.1016/S0040-4039(02)00603-2

Asymmetric C-N bond formation was achieved in a highly enantioselective manner by using (OC)Ru(salen)-catalyzed sulfimidation and the subsequent [2,3]sigmatropic rearrangement: treatment of allyl aryl sulfides with p-toluenesulfonyl azide in the presence of a catalytic amount of (OC)Ru(salen) followed by hydrolysis of the resulting N-allyl-N-arylthio toluenesulfonamides provided N-allyl toluenesulfonamides of high enantiomeric excess.

Full text of DOI:10.1016/S0040-4039(02)00603-2

TETRAHEDRON
LETTERS
Pergamon
Tetrahedron Letters 43 (2002) 3947–3949
Chiral (OC)Ru(salen)-catalyzed tandem sulfimidation and
[2,3]sigmatropic rearrangement: asymmetric CꢀN bond formation
Masakazu Murakami and Tsutomu Katsuki*
Department of Chemistry, Faculty of Science, Graduate School, Kyushu University 33, CREST, JST (Japan Science and
Technology), Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
Received 28 February 2002; accepted 22 March 2002
Abstract—Asymmetric CꢀN bond formation was achieved in a highly enantioselective manner by using (OC)Ru(salen)-catalyzed
sulfimidation and the subsequent [2,3]sigmatropic rearrangement: treatment of allyl aryl sulfides with p-toluenesulfonyl azide in
the presence of a catalytic amount of (OC)Ru(salen) followed by hydrolysis of the resulting N-allyl-N-arylthio toluenesulfon-
amides provided N-allyl toluenesulfonamides of high enantiomeric excess. © 2002 Elsevier Science Ltd. All rights reserved.
Optically active allyl amines are useful chiral building
blocks for the synthesis of various amino compounds.
Thus, a variety of synthetic methods of optically active
allyl amines have been developed.1 Among them, nucleo-
philic substitution of allyl-substituted materials such as
allyl alcohols and allyl acetates with amine or amide
anion derivatives is the most conventional one. This
method generally requires optically active starting
materials, though highly enantioselective allylic substi-
tution reactions of prochiral and racemic substrates
have recently been developed.2 Another useful method
is CꢀN bond formation via [2,3]sigmatropic rearrange-
ment, in particular, the rearrangement of allyl sulfi-
mides because their synthetic precursors, allyl sulfides,
are readily available (Scheme 1).
protected N-allylamines.6 On the other hand, it had
been reported that allyl sulfoxides, oxygen equivalents
of sulfimides, rearrange to the corresponding allyl sulfe-
nates stereospecifically.7 Thus, it was expected that
optically active allyl amine derivatives would be
obtained from allyl sulfides if their sulfimidation occurs
in an enantioselective manner. Indeed, Uemura et al.
developed catalytic enantioselective sulfimidation using
a copper–bis(oxazoline) complex as the catalyst8 and
successfully applied it to the synthesis of N-allyl tolu-
enesulfonamide derivatives via the allylsulfimides,
though enantioselectivity was moderate.9 Recently, we
found highly enantioselective sulfimidation of alkyl aryl
sulfides with (OC)Ru(salen) complex 1 as the catalyst
(Scheme 2).10 On the basis of this result, we examined
enantioselective sulfimidation of allyl aryl sulfides using
1 as the catalyst.
The first example of this type of reaction was reported
by Greenwood et al.3 Subsequent to this, Kresze et al.4
and Sharpless et al.5 independently reported
[2,3]sigmatropic rearrangement of the related sulfin-
amidines. Recently, Bach et al. reported Fe(II)-cata-
lyzed imidation of allyl sulfides and subsequent
[2,3]sigmatropic rearrangement to synthesize N-Boc-
We first examined the reaction of E-crotyl aryl
sulfides11 with arylsulfonyl azides in the presence of
(OC)Ru(salen) 1 as the catalyst (Table 1). Enantioselec-
tivity of the reactions was determined by HPLC analy-
sis after the resulting chiral N-allyl-N-arylthio
R3
R3
HN
[2,3]sigmatropic
rearrangement
R2
R3
R1
R2
hydrolysis
R2
R2
N-
S+
*
N
sulfimidation
*
R1S
*
S
R1
R3= ArSO2
allyl sulfide
N-allyl arylsulfonamide
allyl sulfimide
Scheme 1.
* Corresponding author.
0040-4039/02/$ - see front matter © 2002 Elsevier Science Ltd. All rights reserved.
PII: S0040-4039(02)00603-2

3948
M. Murakami, T. Katsuki / Tetrahedron Letters 43 (2002) 3947–3949
Under the optimized conditions, we examined the reac-
Ts
-
N
tions of various other allyl phenyl sulfides with complex
1 as the catalyst in the presence of p-toluenesulfonyl
azide (Table 2). The reactions of E-allyl phenyl sulfides
showed enantioselectivity similar to the reaction of
E-crotyl phenyl sulfide (entries 1–3). The reaction of
Z-pentenyl phenyl sulfide also proceeded with high
enantioselectivity (entry 4). It is, however, noteworthy
that the main enantiomer of the reaction was identical
with the main enantiomer obtained in the reaction of
E-pentenyl phenyl sulfide. Since it is reasonable to
consider that the sense of asymmetric induction in the
reaction of Z-pentenyl phenyl sulfide is identical with
that in the reaction of the corresponding E-substrate,
the above results suggest that the transition state con-
formation in [2,3]sigmatropic rearrangement of the Z-
sulfimide intermediate is different from that of the
E-sulfimide intermediate.13 The poor enantioselectivity
observed in the reaction of geranyl phenyl sulfide that
bears E- and Z- substituents suggests that plural transi-
tion states participate in the rearrangement process
(entry 5).
*
S+
S
(OC)Ru(salen) 1, TsN3
MS 4A, CH2Cl2, rt
98% ee, 99%
R
N
CO
N
O
Ru
O
Ph Ph
R
1
Scheme 2.
arylsulfonamides were hydrolyzed to N-allyl arylsulfon-
amides. The reaction of E-crotyl phenyl sulfide11 with
p-toluenesulfonyl azide at room temperature proceeded
with good enantioselectivity of 78% ee. The enantiose-
lectivity was enhanced as reaction temperature was
decreased, but the reaction became slow at 0°C. The
acceptable result in terms of enantioselectivity and
chemical yield was obtained at 15°C (entry 2). Thus, the
following experiments were carried out at 15°C. Among
the reactions of E-crotyl aryl sulfides examined, that of
E-crotyl phenyl sulfide showed the highest enantioselec-
tivity (entries 2–8): introduction of either an electron-
withdrawing or -donating group into the aryl group
(Ar) slightly reduced enantioselectivity (entries 4–7).
Effect of the arylsulfonyl group of azide was also
examined, but all arylsulfonyl azides used showed a
similar level of enantioselectivity. No electronic effect
on enantioselectivity was observed (entries 9 and 10).
Typical experimental procedure was exemplified by the
reaction of E-crotyl phenyl sulfide and p-toluenesul-
fonyl azide using 1 as the catalyst (Table 1, entry 2):
complex 1 (1.9 mg, 2.0 mmol) was dissolved in dry
toluene (0.5 ml), concentrated azeotropically in vacuo
and re-dissolved in dichloromethane (0.5 ml). To this
solution were added E-crotyl phenyl sulfide (16.4 ml, 0.1
,
mmol) and 4 A MS (20 mg), and the resulting suspen-
sion was stirred for half an hour at 15°C. To this
suspension was added p-toluenesulfonyl azide (19.7 ml,
0.13 mmol) and the whole mixture was stirred for
another 24 h at the temperature. The mixture was
evaporated and the resulting residue was treated with
methanolic 0.5N potassium hydroxide solution (1 ml).
The mixture was stirred for 6 h and filtered through a
Table 1. Asymmetric conversion of E-crotyl aryl sulfide into N-allyl arylsulfonamide using 1 as the catalyst
Entry
Ar
R
E/Za
Yield (%)b
% eec
Config.d
e
f
1
2
3
4
5
6
7
8
9
C6H5
C6H5
C6H5
p-CH3C6H4SO2
p-CH3C6H4SO2
p-CH3C6H4SO2
p-CH3C6H4SO2
p-CH3C6H4SO2
p-CH3C6H4SO2
p-CH3C6H4SO2
p-CH3C6H4SO2
p-CH3OC6H4SO2
p-BrC6H4SO2
81/19
81/19
81/19
76/24
85/15
83/17
85/15
83/17
81/19
81/19
82
65
16
47
79
79
22
88
57
69
78
84
86
81
80
82
81
78
83
83
R
R
R
R
R
R
R
R
–
p-(O2N)C6H4
p-CH3OC6H4
p-BrC6H4
o-BrC6H4
2-C10H7
c
C6H5
C6H5
c
10
–
a E/Z-isomer ratio of the starting material.
b Isolated yield.
c Determined by HPLC analysis using DAICEL CHIRALCEL AD-H (hexane/2-propanol=9:1).
d Absolute configuration was determined by comparison of the sign of specific optical rotation with the reported one (Ref. 12).
e Reaction was carried out at room temperature.
f Reaction was carried out at 0°C

M. Murakami, T. Katsuki / Tetrahedron Letters 43 (2002) 3947–3949
3949
Table 2. Asymmetric conversion of various allyl phenyl sulfides into N-toluenesulfonylallylamine using 1 as the catalyst
Entry
R1
R2
E/Za
Yield (%)b
% eec
1
2
3
4
5
C2H5
n-C7H15
C6H5
H
H
H
H
C2H5
Me
90/10
89/11
100/0
6/94
48
46
40
66
55
86d
85e
84d
82d
(CH3)2CꢁCHCH2CH2
98/2
B1e
a E/Z-isomer ratio of the starting material.
b Isolated yield.
c Absolute configuration of the product has not been determined.
d Determined by HPLC using DAICEL CHIRALCEL AD-H (hexane/2-propanol=9/1).
e Determined by HPLC using DAICEL CHIRALCEL AD-H (hexane/ethanol=30/1).
pad of Celite. The filtrate was evaporated, treated with
1N hydrochloric acid, and extracted with ether. The
organic layer was washed with saturated sodium chlo-
ride solution and dried over anhydrous sodium sulfate.
The mixture was concentrated and chromatographed
on silica gel (hexane:diethyl ether=7:3) to give N-(1-
methyl-2-propen-1-yl) p-toluenesulfonamide (14.6 mg,
65% yield). The enantiomeric excess of the product was
determined to be 84% by HPLC analysis using
DAICEL CHIRALCEL AD-H (hexane/2-propanol=
9:1).
J. Am. Chem. Soc. 2001, 123, 6508–6519; (h) For a review
of allylic amination, see: Johannsen, M.; Jørgensen, K. A.
Chem. Rev. 1998, 98, 1689–1708.
3. Ash, A. S. F.; Challenger, F.; Greenwood, D. J. Chem.
Soc. 1951, 1877–1882.
4. Scho¨nberger, N.; Kresze, G. Liebigs Ann. Chem. 1975,
1725–1731.
5. (a) Sharpless, K. B.; Hori, T. J. Org. Chem. 1976, 41,
176–177; (b) Sharpless, K. B.; Hori, T.; Truesdale, L. K.;
Dietrich, C. O. J. Am. Chem. Soc. 1976, 98, 269–271.
6. Bach, T.; Ko¨rber, C. J. Org. Chem. 2000, 65, 2358–2367.
7. Hoffmann, R. W. Angew. Chem., Int. Ed. Engl. 1979, 18,
563–572.
In conclusion, we were able to demonstrate that N-allyl
arylsulfonamides can be prepared from allyl phenyl
sulfides by using enantioselective sulfimidation with
(OC)ruthenium(salen) complex 1 as the key step.
8. Miyake, Y.; Takada, H.; Ohe, K.; Uemura, S. J. Chem.
Soc., Perkin Trans. 1 1998, 18, 2373–2376.
9. (a) Takada, H.; Nishibayashi, Y.; Ohe, K.; Uemura, S. J.
Chem. Soc., Chem. Commun. 1996, 931–932; (b) Takada,
H.; Nishibayashi, Y.; Ohe, K.; Uemura, S.; Baird, C. P.;
Sparey, T. J.; Taylor, P. C. J. Org. Chem. 1997, 62,
6512–6518.
10. Murakami, M.; Uchida, T.; Katsuki, T. Tetrahedron Lett.
2001, 42, 7071–7074.
11. The starting crotyl aryl sulfides were prepared from com-
mercial crotyl bromide (E:Z=81:19) and used for the
present reaction without separation of geometric isomers
because of difficulty of their separation.
References
1. Jørgensen, K. A. In Modern Amination Methods; Ricci,
A., Ed.; Wiley-VCH: Weinheim, 2000; Chapter 1.
2. (a) Hayashi, T.; Yamamoto, A.; Ito, Y.; Nishioka, E.;
Miura, H.; Yanagi, K. J. Am. Chem. Soc. 1989, 111,
,
6301–6311; (b) Connell, R. D.; Rein, T.; Akermark, B.;
Helquist, P. J. Org. Chem. 1988, 53, 3845–3849; (c)
Burckhardt, U.; Baumann, M.; Trabesinger, G.; Gram-
lich, V.; Togni, A. Organometallics 1997, 16, 5252–5259;
(d) Trost, B. M.; Van Vranken, D. L. Chem. Rev. 1996,
96, 395–422; (e) Trost, B. M.; Radinov, R. J. Am. Chem.
Soc. 1997, 119, 5962–5963; (f) Evans, D. A.; Campos, K.
R.; Tedrow, J. S.; Michael, F. E.; Gagne´, M. R. J. Am.
Chem. Soc. 2000, 122, 7905–7920; (g) Deng, W.-P.; You,
S.-L.; Hou, X.-L.; Dai, L.-X.; Yu, Y.-H.; Xia, W.; Sun, J.
12. Moriwake, T.; Hamano, S.; Saito, S.; Kashino, S.; Torii,
S. J. Org. Chem. 1989, 54, 4114–4120.
13. A similar stereochemistry was observed in the
[2,3]sigmatropic rearrangement of S-ylides derived from
allyl sulfides: the reactions of E- and Z-cinnamyl phenyl
sulfides gave the same product: Fukuda, T.; Irie, R.;
Katsuki, T. Tetrahedron 1999, 55, 649–664.