Chiral binaphthylthiophosphoramide - Cu(I)-catalyzed asymmetric addition of diethylzinc to N-sulfonylimines

Article abstract of DOI:10.1021/jo034269n

In the presence of a catalytic amount of chiral binaphthylthiophosphoramide L2 (6 mol %) and Cu(I) (3 mol %), the asymmetric addition of diethylzinc to N-sulfonylimines could be achieved in good yields with moderate to high ee (63-93% ee) at 0 °C in tolue

Full text of DOI:10.1021/jo034269n

Ch ir a l Bin a p h th ylth iop h osp h or a m id e-Cu (I)-Ca ta lyzed
Asym m etr ic Ad d ition of Dieth ylzin c to N-Su lfon ylim in es
Chun-J iang Wang and Min Shi*
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry,
Chinese Academy of Science, 354 Fenglin Lu, Shanghai 200032, China
mshi@pub.sioc.ac.cn
Received March 1, 2003
In the presence of a catalytic amount of chiral binaphthylthiophosphoramide L2 (6 mol %) and
Cu(I) (3 mol %), the asymmetric addition of diethylzinc to N-sulfonylimines could be achieved in
good yields with moderate to high ee (63-93% ee) at 0 °C in toluene. A novel chiral binaphthyl-
thiophosphoramide ligand system for this asymmetric addition reaction has been explored.
Efficient and catalytic asymmetric preparation of
amines is one of the most promising methodologies in
homogeneous catalysis.1 Enantioselective addition of
organometallic reagents to CdN of imines is a convenient
route to obtain optically active amines.2 This approach
has especially been used in chiral amine ligand-catalyzed
asymmetric addition of alkyllithium;3 chiral amino alco-
hol ligands,4 copper-amidophosphines,5 and Zr-peptide-
based chiral ligand-catalyzed asymmetric addition of
organozinc;6 chiral allylpalladium-catalyzed allylation by
allylstannane;7 and rhodium-monophosphine-catalyzed
arylation by arylstannane8 with very good enantioselec-
tivities. Recently, we have been interested in the syn-
theses and applications of novel ligands based on the
axially chiral binaphthalenediamine (BINAM).9 In the
field of catalytic asymmetric synthesis, BINAM has been
much less popular than the widely used other axially
chiral binaphthalene skeletons such as BINOL and
NOBIN or other chiral diamines such as 1,2-cyclohex-
anediamine and 1,2-diphenylethenediamine.10 Herein, we
wish to report the synthesis of novel axially chiral
binaphthylthiophosphoramide ligands L1-L7 and the
results of our studies on catalytic enantioselective addi-
tion of diethylzinc to N-sulfonylimines.
Resu lts a n d Discu ssion
These chiral ligands L1-7 are easily obtained from (R)-
(+)-1,1′-binaphthyl-2,2′-diamine.11 The procedures for the
preparation of the ligands are outlined in Scheme 1. They
can be easily synthesized through lithiation of the
relevant diamine with butyllithium and then phospho-
rylation with dialkylthiophosphoryl chloride. In addition,
they are quite stable and can be easily recovered from
the reaction mixture in 85% yield through column chro-
matography after the usual workup and can be reused
in this asymmetric reaction without loss of enantioselec-
tivity.
Using N-(p-fluorobenzylidene)-p-methylbenzenesulfona-
mide (N-sulfonylimine) 5j as the substrate and diethyl-
zinc as the nucleophilic addition reagent, we examined
this asymmetric addition in toluene under various reac-
tion conditions to develop the optimal reaction conditions.
The results are summarized in Table 1.
* Corresponding author. Fax: 86-21-64166128.
(1) Federsel, H.-J .; Collins, A. N.; Sheldrake, G. N.; Crosby, J .
Chirality in Industry II; J ohn Wiley & Sons: Chichester, UK, 1997;
pp 225-244.
(2) For a review on catalytic asymmetric additions to imines, see:
Kobayashi, S.; Ishitani, H. Chem. Rev. 1999, 99, 1069-1094.
(3) (a) Denmark, S. E.; Nakajima, N.; Nicaise, O. J .-C. J . Am. Chem.
Soc. 1994, 116, 8797-8798. (b) Denmark, S. E.; Stiff, C. M. J . Org.
Chem. 2000, 65, 5875-5878. (c) Tomioka, K.; Inoue, I.; Shindo, M.;
Koga, K. Tetrahedron Lett. 1991, 32, 3095-3098.
(4) (a) Soai, K.; Hatanaka, T.; Miyazawa, T.; J . Chem. Soc., Chem.
Commun. 1992, 1097-1098. (b) Andersson, P. G.; Guijarro, D.; Tanner,
D. J . Org. Chem. 1997, 62, 7364-7375. (c) Brandt, P.; Hedberg, C.;
Lawonn, K.; Pinho, P.; Andersson, P. G. Chem. Eur. J . 1999, 5, 1692-
1699. (d) J imeno, C.; Reddy, K. S.; Sola, L.; Moyano, A.; Pericas, M.
A.; Riera, A. Org. Lett. 2000, 2, 3157-3159. (e) Frantz, D. E.; Fassler,
R.; Carreira, E. M. J . Am. Chem. Soc. 1999, 121, 11245-11246. (f)
Dahmen, S.; Bra¨se, S. J . Am. Chem. Soc. 2002, 124, 5940-5941.
(5) (a) Fujihara, H.; Nagai, K.; Tomika, K. J . Am. Chem. Soc. 2000,
122, 12055-12056. (b) Boezio, A. A.; Charette, A. B. J . Am. Chem.
Soc. 2003, 125, 1692-1693.
In an early study, an examination of the temperature
profile of Cu(CH3CN)4BF4/L4-catalyzed asymmetric ad-
dition of diethylzinc to N-sulfonylimines was performed.
We found that the reaction temperature had a great
influence on the yield and enantioselectivity of the
addition product 6j. At room temperature, the reaction
(6) (a) Porter, J . R.; Traverse, J . F.; Hoveyda, A. H.; Snapper, M. L.
J . Am. Chem. Soc. 2001, 123, 984-985 and 10409-10410. (b) Wipf,
P.; Kendall, C.; Stephenson, C. R. J . J . Am. Chem. Soc. 2001, 123,
5122-5123. (c) Wei, C.-M.; Li, C.-J . J . Am. Chem. Soc. 2002, 124,
5638-5939.
(9) (a) Shi, M.; Sui, W. S. Chiraliy 2000, 12, 574-580. (b) Shi, M.;
Sui, W. S. Tetrahedron: Asymmetry 2000, 11, 773-779. (c) Shi, M.;
Sui, W. S. Tetrahedron: Asymmetry 2000, 11, 835-841. (d) Shi, M.;
Sui, W. S. Tetrahedron: Asymmetry 1999, 10, 3319-3325.
(10) (a) Ojima, I. Ed. Catalytic Asymmetric Synthesis; VCH Publica-
tions: New York, 1993. (b) J acobsen, E. N.; Pfaltz, A., Yamamoto, H.,
Eds.; Comprehensive Asymmetric Catalysis; Springer-Verlag: Heidel-
berg, 2001.
(7) (a) Nakamura, H.; Nakamura, K.; Yamamoto, Y. J . Am. Chem.
Soc. 1998, 120, 4242-4243. (b) Bao, M.; Nakamura, H.; Yamaoto, Y.
Tetrahedron Lett. 2000, 41, 131-134.
(8) Hayashi, T.; Ishigedani, M. J . Am. Chem. Soc. 2000, 122, 976-
977.
(11) Miyano, S.; Nawa, M.; Mori, A.; Hashimoto, H. Bull. Chem. Soc.
J pn. 1984, 57, 2171-2176.
10.1021/jo034269n CCC: $25.00 © 2003 American Chemical Society
Published on Web 07/03/2003
J . Org. Chem. 2003, 68, 6229-6237
6229

Wang and Shi
SCHEME 1. P r ep a r a tion of Ch ir a l Bin a p h th ylth iop h osp h or a m id e Liga n d s
was quickly completed within 1 h. However, the desired
ethylation product 6j was given in 59% yield (61% ee)
along with the corresponding byproduct in 39% yield
(Table 1, entry 1). Lowering the reaction temperature to
0 °C diminished the yield of the byproduct to 4%, and
the yield of the addition product 6j was increased to 90%
with 79% ee (Table 1, entry 2). When the reaction was
carried out at -20 °C, the byproduct was not detected,
but the reaction was sluggish and the achieved ee of 6j
was remarkably reduced to 55% (Table 1, entry 3). Thus,
the best reaction temperature is 0 °C. The catalytic
activity of Cu(CH3CN)4BF4 was higher than that of other
copper salts such as Cu(CH3CN)4ClO4, CuOTf‚1/2C6H6,
and Cu(OTf)2 (Table 1, entries 2 and 10-12). The
counterion effect has been checked by use of CuOTf and
CuBF4 freshly prepared in situ via the reaction of CuBr
with AgOTf and AgBF4, respectively, in the same cata-
lytic asymmetric addition reaction.12 As a result, we
found that the obtained yield and ee of the addition
product 6j were the same as those of CuOTf‚1/2 C6H6 and
Cu(CH3CN)4BF4. This result suggested that the slight
differences caused by Cu(CH3CN)4BF4, Cu(CH3CN)4ClO4,
and CuOTf‚1/2C6H6 were due to the counterion effect and
had no relation to the nature of copper. By screening
chiral ligands L1-7, we found that L2 was the best chiral
ligand for this enantioselective addition reaction, which
gave the addition product in 90% ee and 96% yield at 0
°C (Table 1, entry 5). It should be noted that chiral ligand
L5, having an N,N-dimethyl group, gave the addition
product 6j in 33% ee under the same conditions (Table
1, entry 7), and N-unsubstituted chiral ligands such as
L1, L3, and L6 gave the addition product 6j only in
moderate ee as well (Table 1, entries 4, 6, and 8). These
results suggested that the substituent on the amino
group in the binaphthyl structure played a very impor-
tant role in chiral induction in this asymmetric addition
reaction. We also found that the yield and enantioselec-
tivity of the desired product were not affected by the
sequence of addition of diethylzinc and substrate to the
solution of the Cu/ligand mixture (Table 1, entries 5 and
13-15). The recovered L2 gave the addition product in
similar yield and enantioselectivity (Table 1, entry 16).
Using L2 as a chiral ligand, we examined the solvent
effect as well. We found that toluene is the best solvent
for this asymmetric reaction (Table 1, entries 5 and 17-
19). In addition, the reaction was also completed within
8 h with a slightly decreased yield and ee using 1.5 mol
% copper salt and 3 mol % ligand (Table 1, entry 20).
The best reaction conditions used Cu(CH3CN)4BF4 (3 mol
%) as a precursor and L2 (6 mol %) as chiral ligand in
toluene at 0 °C.
We next examined the asymmetric addition reaction
of diethylzinc to a variety of N-sulfonylimines 5 under
the optimized reaction conditions. The results are sum-
marized in Table 2.
As can be seen from Table 2, high yields and good
enantioselectivities could be achieved for various aro-
matic N-sulfonylimines 5 having either electron-donating
groups or electron-withdrawing groups on the benzene
ring (Table 2, entries 1-12). These results are compa-
rable with the best literature value hitherto reported for
(12) Evans previously pointed out that highly electronegative coun-
terions are a design prerequisite for efficient asymmetric catalysis. (a)
Evans, D. A.; Faul, M. M.; Bilodeau, M. T.; Anderson, B. A.; Barnes,
D. M. J . Am. Chem. Soc. 1993, 115, 5328-5329. (b) Evans, D. A.;
Woerpel, K.; Hinman, M. M.; Faul, M. M. J . Am. Chem. Soc. 1991,
113, 726-728.
6230 J . Org. Chem., Vol. 68, No. 16, 2003

Catalytic Asymmetric Addition of Diethylzinc to N-Sulfonylimines
TABLE 1. Asym m etr ic Ad d ition Rea ction of Dieth ylzin c to N-Su lfon ylim in e 5j Ca ta lyzed by Cop p er Sa lt a n d Ch ir a l
Liga n d s L1-7
temp
(°C)
time
(h)
yielda
(%)
eeb
(%)
entry
copper salt
ligand
solvent
1
2
3
4
5
6
7
8
9
10
11
12
13
14d
15d
16d
17e
18
19
20f
Cu(MeCN)4BF4
Cu(MeCN)4BF4
Cu(MeCN)4BF4
Cu(MeCN)4BF4
Cu(MeCN)4BF4
Cu(MeCN)4BF4
Cu(MeCN)4BF4
Cu(MeCN)4BF4
Cu(MeCN)4BF4
Cu(MeCN)4ClO4
CuOTf‚1/2C6H6
Cu(OTf)2
L4
L4
L4
L1
L2
L3
L5
L6
L7
L4
L4
L4
L2
L2
L2
L2
L2
L2
L2
L2
PhCH3
PhCH3
PhCH3
PhCH3
PhCH3
PhCH3
PhCH3
PhCH3
PhCH3
PhCH3
PhCH3
PhCH3
PhCH3
PhCH3
PhCH3
PhCH3
Et2O
20
0
-20
1
8
40
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
59
90
68
85
96
33
64
77
80
92
88
90
96
92
95
94
65
71
trace
92
61c
79
55
63
90
61
33
16
34
65
71
71
88
87
86
89
84
83
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Cu(OTf)2
Cu(OTf)2
Cu(MeCN)4BF4
Cu(MeCN)4BF4
Cu(MeCN)4BF4
Cu(MeCN)4BF4
Cu(MeCN)4BF4
Cu(MeCN)4BF4
THF
CH2Cl2
PhCH3
8
8
0
86
a
b
d
Isolated yields. Determined by chiral HPLC. c Byproduct was also isolated to 39% yield. Treatment of a solution of Cu salt and
ligand with Et2Zn, followed by addition of sulfonylimine into the reaction solution. e Recovered L2 was used. f Used 1.5 mol % copper salt
and 3 mol % ligand.
the asymmetric addition of diethylzinc to N-sulfonyl-
imines.5a For the methanesulfonylimine 5m and 2-tri-
methylsilylethanesulfonylimine 5n , 96% yield (87% ee)
and 94% yield (80% ee) also could be realized, respectively
(Table 2, entries 13 and 14). Only for aliphatic sulfo-
nylimine 5o was the corresponding addition product 6o
obtained with only moderate ee (63% ee) (Table 2, entry
15).
The sulfur on phosphorus was crucial for this catalytic
asymmetric reaction because the corresponding axially
chiral binaphthyldiphenylphosphoramide ligand L8
showed very low catalytic activity for this reaction. The
corresponding addition product 6j was formed in trace
amounts, and the byproduct was obtained in 32% yield
along with a large amount of unreacted starting materi-
als (Scheme 2). Although the real active species is not
yet fully understood in this catalytic addition reaction,
we believe that this family of binaphthylthiophosphora-
mides L1-7 are bidentate ligands in this catalytic
asymmetric reaction because it is well-known that sulfur
atoms can coordinate strongly to late transition metals.13
To get the evidence of the coordination of aniline nitrogen
and sulfur atom to Cu(I), 13C NMR and 31P NMR studies
of a 1:1 mixture of L4 and Cu(CH3CN)4BF4 in CDCl3 at
room temperature were carried out. In the absence of Cu-
(CH3CN)4BF4, the carbon signals of the two carbons in
the ethyl group of L4 appeared at δ 38.31 and 15.00
(Figure 1), but the two corresponding carbons signals
appeared at δ 40.92 and 14.88 in the presence of Cu(CH3-
CN)4BF4, respectively (Figure 2). Meanwhile, another
new carbon signal was observed at δ 1.88, which was
attributed to the carbon of methyl group in acetonitrile.
In addition, the signal of the phosphorus connected to
the sulfur atom in L4 appeared at δ 53.28 in the absence
of Cu(CH3CN)4BF4 (Figure 3), while it was shifted to δ
55.52 in L4 in the presence of Cu(CH3CN)4BF4 (Figure
4). Those results may indicate that Cu(I) can be poten-
tially coordinated by both the S and N atoms in ligand
L4.
Con clu sion
In conclusion, we have synthesized a new family of
axially chiral binaphthylthiophosphoramides that are
(13) For selected X-rays of Cu complexes coordinated by S,N-ligands,
see: (a) Koten, D. M.; Grove, D. M.; Smeets, W. J .; Spek, A. L.; van
Koten, G. J . Am. Chem. Soc. 1992, 114, 3400-3410. (b) Brubaker, G.
R.; Brown, J . N.; Yoo, M. K.; Kutchan, T. M.; Mottel, E. A. Inorg. Chem.
1979, 18, 299-302.
J . Org. Chem, Vol. 68, No. 16, 2003 6231

Wang and Shi
TABLE 2. Asym m etr ic Ad d ition of Dieth ylzin c to
Va r iou s N-Su lfon ylim in es 5 in th e P r esen ce of Cu (I) (3
m ol %) a n d L2 (6 m ol %)
yielda
(%)
eeb
[R]25
D
entry
R
R′
Ts
Ts
Ts
imine
(%) (c in CHCl3)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
C6H5
5a
5b
5c
5d
5e
5f
5g
5h
5i
5j
5k
5l
5m
5n
5o
6a , 93
6b, 95
6c, 93
6d , 81
6e, 96
6f, 93
6g, 95
6h , 91
6i, 94
6j, 96
6k , 95
6l, 93
86 -52.2 (2.97)c
86 -67.3 (2.48)
86 -60.6 (2.35)
90 -80.1 (1.50)
91 -52.4 (3.90)
86 -57.3 (5.80)
93 -39.7 (2.25)
92 -25.5 (1.25)
85 -52.5 (4.70)
90 -39.7 (0.72)
82 -74.1 (0.68)
p-MeC6H4
m-MeC6H4
p-MeOC6H4 Ts
p-ClC6H4
m-ClC6H4
p-CF3C6H4
p-BrC6H4
m-FC6H4
p-FC6H4
2-furyl
Ts
Ts
Ts
Ts
Ts
Ts
Ts
F IGURE 2. 13C NMR spectrum of the mixture of L4 and Cu-
(CH3CN)4BF4.
1-naphthyl Ts
88
+9.1 (1.25)
C6H5
Ms
SES
Ts
6m , 96 87 -38.6 (2.63)
6n , 94
6o, 86
p-ClC6H4
i-Me2CH
80 -14.0 (1.70)
63 -6.2 (3.25)
a
b
Isolated yields. Determined by chiral HPLC. c Absolute con-
figuration of 6a was assigned as S by comparing the optical
rotation with the reported data.5a
F IGURE 3. 31P NMR spectrum of L4.
F IGURE 1. 13C NMR spectrum of L4.
SCHEME 2. Asym m etr ic Ad d ition Rea ction of
Dieth ylzin c to N-Su lfon ylim in e 5j in th e P r esen ce
of Cu (I) (3 m ol %) a n d Ch ir a l Liga n d L8 (6 m ol %)
F IGURE 4. 31P NMR spectrum of the mixture of L4 and Cu-
(CH3CN)4BF4.
Exp er im en ta l Section
Gen er a l Rem a r k s. All reactions were conducted in oven-
(135 °C) and flame-dried glassware under an inert atmosphere
of dry argon or nitrogen. Toluene was distilled from sodium
metal; dichloromethane was distilled from calcium hydride,
and diethyl ether, tetrahydrofuran, and benzene were distilled
easily available, very stable, and recoverable and have
applied them to the copper-catalyzed asymmetric addi-
tion of diethylzinc to N-sulfonylimines 5 with high yields
and moderate to good enantioselectivities. Efforts are
underway to elucidate the mechanistic details of this
catalytic system and to extend the scope of these novel
chiral ligands in other asymmetric C-C bond-forming
transformations.
1
from sodium metal/benzophenone ketyl. H NMR, 13C NMR,
and 31P NMR spectra were recorded at 300, 75, and 121 MHz,
respectively. Mass spectra were recorded by the EI method.
All of the solid compounds reported in this paper gave
satisfactory CHN microanalyses. Commercially obtained re-
agents were used without further purification. All reactions
were monitored by TLC with silica gel-coated plates. Enan-
tiomeric ratios were determined by HPLC, using a chiralpak
AS column, a chiralpak AD column or a chiralcel OD column
6232 J . Org. Chem., Vol. 68, No. 16, 2003

Catalytic Asymmetric Addition of Diethylzinc to N-Sulfonylimines
with hexane and i-PrOH as solvents. Melting points are
uncorrected.
1584, 1507, 1413, 1320, 1290, 1233, 1162, 1151, 1088, 879, 842,
809, 771 cm-1 1H NMR (CHCl3, TMS, 300 MHz) δ 2.45 (s,
;
3H, Me), 7.19 (m, 2H, ArH), 7.36 (d, J ) 8.1 Hz, 2H, ArH),
7.89 (d, J ) 8.1 Hz, 2H, ArH), 7.97 (m, 2H, ArH), 9.01 (s, 1H,
CH); 13C NMR (CDCl3, TMS, 75 MHz) δ 21.64, 116.60 (d, J )
22.0 Hz), 128.04, 128.67 (d, J ) 2.9 Hz), 129.82, 133.78 (d, J
) 9.6 Hz), 134.89, 144.86, 166.77 (d, J ) 257.0 Hz), 168.53;
MS (EI) m/z 277 ([M]+•, 25.61), 155 ([M - 122]+, 83.32), 122
([M - 155]+, 3.78), 91 ([M - 186]+, 100.00). Anal. Calcd for
Ma ter ia ls. N-Benzylidene-p-methylbenzenesulfonamides
5a -l,14 N-benzylidene-methylsulfonamide 5m ,15 N-(p-chlo-
robenzylidene)-â-trimethylsilylethanesulfonamide 5n ,16 and
N-isobutylidene-p-methyl- benzenesulfonamide 5o17 were pre-
pared by the reported synthetic methods. The physical and
spectroscopic data of 5a , 5b, 5d , 5f, 5h , 5k , and 5l-o are
consistent with those reported in the literature.14-18 For new
starting materials 5c, 5e, 5g, 5i, and 5j, the physical and
spectroscopic data have been elucidated as follows.
C
14H12FNO2S: C, 60.63; H, 4.36; N, 6.85. Found: C, 60.55; H,
4.58; N, 6.74.
N -(3-Me t h ylb e n zylid e n e )-p -m e t h ylb e n ze n e su lfon a -
m id e 5c: yield 73%; mp 88-89 °C; IR (KBr) ν 1614, 1592,
1571, 1480, 1425, 1318, 1292, 1255, 1160, 1087, 1006, 997, 921,
809 cm-1; 1H NMR (CHCl3, TMS, 300 MHz) δ 2.39 (s, 3H, Me),
2.44 (s, 3H, Me), 7.37 (m, 4H, ArH), 7.73 (m, 2H, ArH), 7.89
(d, J ) 7.8 Hz, 2H, ArH), 9.0 (s, 1H, CH); 13C NMR (CDCl3,
TMS, 75 MHz) δ 21.11, 21.64, 128.02, 128.98, 129.77, 131.27,
132.22, 135.06, 135.85, 139.04, 144.55, 170.35; MS (EI) m/z
273 ([M]+•, 8.18), 155 ([M - 118]+, 45.40), 118 ([M - 155]+,
14.20), 91 ([M - 182]+, 100.00). Anal. Calcd for C15H15NO2S:
C, 65.91; H, 5.53; N, 5.12. Found: C, 65.87; H, 5.55; N, 5.12.
N -(4-Ch lor ob e n zylid e n e )-p -m e t h ylb e n ze n e su lfon a -
m id e 5e: yield 75%; mp 175-176 °C; IR (KBr) ν 1606, 1593,
1561, 1487, 1402, 1318, 1304, 1164, 1084, 1011, 871, 825, 800,
787 cm-1; 1H NMR (CHCl3, TMS, 300 MHz) δ 2.41 (s, 3H, Me),
7.32 (d, J ) 8.3 Hz, 2H, ArH), 7.43 (d, J ) 8.3 Hz, 2H, ArH),
7.84 (m, 4H, ArH), 8.96 (s, 1H, CH); 13C NMR (CDCl3, TMS,
75 MHz) δ 21.63, 128.06, 129.52, 129.80, 130.68, 132.30,
134.71, 141.34, 144.75, 168.60; MS (EI) m/z 293 ([M]+•, 20.98),
155 ([M - 138]+, 81.78), 111 ([M - 182]+, 13.56), 91 ([M -
202]+, 100.00). Anal. Calcd for C14H12ClNO2S: C, 57.23; H,
4.12; N, 4.77. Found: C, 57.39; H, 3.97; N, 4.64.
Syn th esis of (R)-(+)-N-Acetyl-1,1′-bin a p h th yl-2,2′-d i-
a m in e 1. Acetic anhydride (208 µL, 2.2 mmol) was added to a
mixture of (R)-(+)-binaphthyldiamine (568 mg, 2 mmol), acetic
acid (1.2 mL, 20 mmol), and dichloromethane (20.0 mL) with
ice-cooling. The mixture was stirred at room temperature
overnight, and 2.0 N NaOH was added until pH > 7. After
extraction with dichloromethane, the combined organic layers
were dried over MgSO4. The residue obtained upon evapora-
tion was purified by column chromatography to afford the
product 1 as a colorless solid (509 mg, 78%): mp 240-241 °C;
[R]25 ) +40.0 (c 0.55, CHCl3); IR (KBr) ν 3400, 1675, 1595,
D
1500, 1445, 1270, 1040, 965, 670 cm-1; 1H NMR (CHCl3, TMS,
300 MHz) δ 1.85 (s, 3H, Me), 6.91-7.42 (m, 8H, ArH and
NHCO), 7.81-8.03 (m, 4H, ArH), 8.58 (d, J ) 9.0 Hz, 2H, ArH);
13C NMR (DMSO-d6, TMS, 75 MHz) δ 23.98, 110.31, 119.39,
121.93, 123.77, 124.48, 125.01, 125.03, 125.68, 126.18, 126.92,
127.91, 128.66, 128.71, 129.97, 130.03, 132.06, 133.14, 134.51,
136.16, 144.98, 169.53; MS (EI) m/z 326 ([M]+•, 43.47), 284 ([M
- 42]+, 25.13), 267 ([M - 59]+, 100). Anal. Calcd for C22H18
-
ON2: C, 80.98; H, 5.52; N, 8.59. Found: C, 80.66; H, 5.61; N,
8.48.
Syn t h esis of (R)-(+)-N-E t h yl-1,1′-b in a p h t h yl-2,2′-d i-
a m in e 2. To a stirred suspension of LiAlH4 (280 mg, 7.37
mmol) in 30.0 mL of anhydrous THF was added dropwise a
solution of 1 (509 mg, 1.56 mmol) in 10.0 mL of THF. The
mixture was heated under reflux for 4 h. The reaction mixture
was cooled in an ice-bath, and the remaining hydride was
carefully quenched by dropwise addition of water (5.0 mL) and
then 10% NaOH (5.0 mL). A white precipitate was filtered off
and thoroughly washed with ethyl acetate. The combined
filtrate and ethyl acetate washings were washed with brine
and dried over MgSO4. After the solvents were evaporated
under reduced pressure, the product was purified by flash
chromatography to afford the product 2 (470 mg, 97%) as a
N-(4-Tr iflu or om eth ylben zylid en e)-p-m eth ylben zen e-
su lfon a m id e 5g: yield 65%; mp 159-160 °C; IR (KBr) ν 1617,
1577, 1413, 1327, 1318, 1173, 1161, 1131, 1107, 1089, 1063,
1018, 998, 873, 841, 804, 789 cm-1 1H NMR (CHCl3, TMS,
;
300 MHz) δ 2.47 (s, 3H, Me), 7.38 (d, J ) 8.1 Hz, 2H, ArH),
7.76 (d, J ) 8.4 Hz, 2H, ArH), 7.91 (d, J ) 8.4 Hz, 2H, ArH),
8.06 (d, J ) 8.1 Hz, 2H, ArH), 9.09 (s, 1H, CH); 13C NMR
(CDCl3, TMS, 75 MHz) δ 21.67 123.24 (q, J ) 271.4 Hz), 126.05
(q, J ) 7.4 Hz), 128.22, 129.90, 131.32, 134.28, 135.33 (q, J )
1.6 Hz), 135.67 (q, J ) 32.7 Hz), 145.07, 168.40; MS (EI) m/z
327 ([M]+•, 16.89), 155 ([M - 172]+, 78.31), 145 ([M - 182]+,
9.18), 91 ([M - 236]+, 100.00). Anal. Calcd for C15H12F3NO2S:
C, 55.04; H, 3.70; N, 4.28. Found: C, 55.16; H, 3.58; N, 4.06.
N -(3-F lu or ob e n zylid e n e )-p -m e t h ylb e n ze n e su lfon a -
m id e 5i: yield 77%; mp 93-94 °C; IR (KBr) ν 1660, 1610, 1576,
1488, 1322, 1289, 1256, 1160, 1089, 946, 878, 832, 814, 791,
755 cm-1; 1H NMR (CHCl3, TMS, 300 MHz) δ 2.45 (s, 3H, Me),
7.38 (m, 4H, ArH), 7.64 (m, 2H, ArH), 7.89 (d, J ) 8.4 Hz, 2H,
ArH), 9.0 (d, J ) 1.2 Hz, CH); 13C NMR (CDCl3, TMS, 75 MHz)
δ 21.65, 116.44 (d, J ) 22.4 Hz), 121.93 (d, J ) 21.5 Hz), 127.88
(d, J ) 2.8 Hz), 128.13, 129.86, 130.83 (d, J ) 7.7 Hz), 134.35
(d, J ) 7.2 Hz), 134.55, 144.91, 162.74 (d, J ) 247.9 Hz), 168.77
(d, J ) 2.9 Hz); MS (EI) m/z 277 ([M]+•, 27.38), 155 ([M - 122]+,
74.57), 122 ([M - 155]+, 9.71), 91 ([M - 186]+, 100.00). Anal.
Calcd for C14H12FNO2S: C, 60.63; H, 4.36; N, 6.85. Found: C,
60.77; H, 4.33; N, 7.03.
colorless solid: mp 123-124 °C; [R]25 ) +175.2 (c 0.63,
D
CHCl3); IR (KBr) ν 3385, 3060, 2985, 2910, 1645, 1598, 1510,
1
1425, 1350, 1150, 915, 820 cm-1; H NMR (CDCl3, TMS, 300
MHz) δ 0.99 (t, J ) 7.5 Hz, 3H, Me), 3.18 (q, J ) 7.5 Hz, 2H,
CH2), 3.60 (br, 3H, amino-H), 6.96-7.25 (m, 8H, ArH), 7.75-
7.87 (m, 4H, ArH); 13C NMR (CDCl3, TMS, 75 MHz) δ 15.57,
39.02, 112.62, 112.84, 114.69, 118.71, 122.28, 122.79, 124.15,
124.36, 127.09, 127.19, 128.03, 128.50, 128.54, 128.80, 129.86,
129.96, 134.01, 134.30, 143.35, 144.73; MS (EI) m/z 313 ([M +
1]+•, 100.00), 297 ([M - 15]+, 34.21), 280 ([M - 32]+, 42.91),
267 ([M - 45]+, 25.99). Anal. Calcd for C22H20N2: C, 84.62; H,
6.41; N, 8.97. Found: C, 84.53; H, 6.56; N, 8.95.
Syn th esis of (R)-(+)-N-Acetyl-N′,N′-d im eth yl-1,1′-bi-
n a p h th yl-2,2′-d ia m in e 3. A solution of 1 (163 mg, 0.5 mmol)
in THF (10 mL) and NaBH4 (133 mg, 3.5 mmol) were
simultaneously added to a stirred solution of 20% H2SO4 (0.5
mL) and 40% formaldehyde aqueous solution (0.5 mL, 6.0
mmol) in THF (20 mL) with ice-cooling over a period of 15 min.
The mixture was stirred for an additional hour and then 1.0
N NaOH was added until pH > 7. After extraction with ethyl
acetate, the combined organic layers were dried over MgSO4.
The residue obtained upon evaporation was purified by column
chromatography to afford the product 3 as a colorless solid
N -(4-F lu or ob e n zylid e n e )-p -m e t h ylb e n ze n e su lfon a -
m id e 5j: yield 75%; mp 111-112 °C; IR (KBr) ν 1609, 1597,
(14) Love, B. E.; Raje, P. S.; Williams, T. C. Synlett 1994, 493-494.
(15) Milenkovic, A.; Fache, F.; Faure, R.; Lemaire, M. Synth.
Commun. 1999, 29, 1535-1546.
(16) Xu, Z.; Lu, X. J . Org. Chem. 1998, 63, 5031-5041.
(17) Chemla, F.; Hebbe, V.; Normant, J .-F. Synthesis 2000, 75-77.
(18) (a) Mckay, W. R.; Proctor, G. R. J . Chem. Soc., Perkin Trans. 1
1981, 2435-2442. (b) Shim, J .-G.; Yamamoto, Y. Heterocycles 2000,
52, 2, 885-896. (c) ten Have, R.; Huisman, M.; Meetsma, A.; van
Leuson, A. M. Tetrahedron 1997, 53, 11355-11368. (d) Knipe, A. C.;
McAuley, I. E.; Khandelwal, Y.; Kansal, V. K. Tetrahedron Lett. 1984,
25, 1411-1414. (e) Vass, A.; Dudas, J .; Varma, R. S. Tetrahedron Lett.
1999, 40, 4951-4954.
(108 mg, 61%). mp: 187-189 °C; [R]25 ) -244.5 (c 0.58,
D
CHCl3); IR (KBr) ν 3402, 1684, 1596, 1501, 1427, 929, 669
cm-1 1H NMR (CHCl3, TMS, 300 MHz) δ 1.88 (s, 3H, Me),
;
2.58 (s, 2Me), 6.95 (d, J ) 8.7 Hz, 1H, ArH), 7.12-7.55 (m,
J . Org. Chem, Vol. 68, No. 16, 2003 6233

Wang and Shi
6H, ArH), 7.84-7.80 (m, 4H, ArH), 8.49 (d, J ) 9.0 Hz, 1H,
ArH); 13C NMR (CDCl3, TMS, 75 MHz) δ 24.85, 43.63, 119.02,
121.81, 124.30, 124.62, 125.02, 125.54, 126.64, 126.67, 126.74,
127.04, 128.17, 128.41, 128.84, 129.90, 130.36, 131.30, 133.62,
133.96, 134.12, 149.88, 168.52; MS (EI) m/z 354 ([M]+•, 58.79),
311 ([M - 43]+, 9.83), 296 ([M - 58]+, 17.65), 281 ([M - 73]+,
36.62). Anal. Calcd for C24H22N2O: C, 81.36; H, 6.21; N, 7.91.
Found: C, 81.40; H, 6.39; N, 7.80.
929, 634 cm-1; 1H NMR (CDCl3, TMS, 300 MHz) δ 4.10 (s, br,
2H, NH), 5.12 (d, J ) 7.4 Hz, 1H, NH), 7.0-7.50 (m, 10H,
ArH), 7.50-7.70 (m, 4H, ArH), 7.70-8.0 (m, 8H, ArH); 13C
NMR (CDCl3, TMS, 75 MHz) δ 110.39, 118.25 (d, J ) 4.4 Hz),
119.28 (d, J ) 4.8 Hz), 119.84 (d, J ) 8.9 Hz), 122.67, 124.00,
124.54 (d, J ) 51.7 Hz), 127.12 (d, J ) 27.8 Hz), 127.26, 128.28,
128.33, 128.52, 128.71, 128.95, 130.01 (d, J ) 27.9 Hz), 130.80,
130.95, 131.62 (d, J ) 11.5 Hz), 131.82, 131.86, 131.90, 133.15,
133.41 (d, J ) 51.5 Hz), 133.57, 134.52, 134.93, 137.35, 143.16;
31P NMR (CDCl3, 121 MHz, 85%H3PO4) δ +53.37; MS (EI) m/z
500 ([M]+•, 3.6). Anal. Calcd for C32H25N2PS: C, 76.78; H, 5.03;
N, 5.60. Found: C, 76.65; H, 5.07; N, 5.74.
Syn th esis of (R)-(+)-N,N-Dim eth yl-1,1′-bin a p h th yl-2,2′-
d ia m in e 4. (R)-(+)-N-Acetyl-N′,N′-dimethyl-1,1′-binaphthyl-
2,2′-diamine (300 mg, 0.85 mmol) was added to a stirred
solution of ethanol (25.0 mL) and 4.0 N HCl (9.0 mL), and the
mixture was heated under reflux for 12 h. After cooling of the
mixture to ambient temperature and removal of the ethanol
in vacuo, 2.0 N NaOH was added until pH > 7. After extraction
with dichloromethane, the combined organic layers were dried
over MgSO4. The residue obtained upon evaporation was
purified by column chromatography to afford the product 4 as
a colorless solid (262 mg, 99%): mp 116-118 °C; [R]25D ) +17.4
(c 2.0, CHCl3); IR (KBr) ν 3395, 2794, 1621, 1507, 1426, 1380,
1143, 989, 930, 625 cm-1; 1H NMR (CHCl3, TMS, 300 MHz) δ
2.59 (s, 2Me), 7.0-7.29 (m, 7H, ArH), 7.47 (d, J ) 9.0 Hz, 1H,
ArH), 7.74-7.91 (m, 4H, ArH); 13C NMR (CDCl3, TMS, 75
MHz) δ 38.47, 111.70, 113.46, 114.65, 117.12, 117.17, 118.75,
119.91, 119.99, 121.36, 121.62, 122.98, 123.03, 123.32, 123.91,
124.28, 124.90, 128.71, 129.27, 136.94, 145.23; MS (EI) m/z
312 ([M]+•, 100.00), 297 ([M - 15]+, 4.57), 280 ([M - 32]+,
38.29), 267 ([M - 45]+, 47.97). Anal. Calcd for C22H20N2: C,
84.62; H, 6.41; N, 8.97. Found: C, 84.70; H, 6.55; N, 8.92.
Liga n d 4 (L4): yield 93%; mp 78-80 °C; [R]25 ) -47.5 (c
D
0.905, CHCl3); IR (KBr) ν 1625, 1600, 1515, 1474, 1426, 1055,
898 cm-1; 1H NMR (CDCl3, TMS, 300 MHz) δ 1.11 (t, J ) 7.2
Hz, 3H, Me), 3.27 (q, J ) 7.2 Hz, 2H, CH2), 3.78 (br, 1H, NH),
5.14 (d, J ) 7.5 Hz, 1H, NH), 6.95-7.57 (m, 17 H, ArH), 7.75-
7.91 (m, 5 H, ArH); 13C NMR (CDCl3, TMS, 75 MHz) δ 15.00,
38.31, 109.70, 113.64, 119.11 (d, J ) 4.2 Hz), 119.46 (d, J )
7.9 Hz), 121.87, 123.63, 124.40 (d, J ) 57.9 Hz), 126.73, 126.95,
127.26, 128.35, 128.36 (d, J ) 28.8 Hz), 128.37, 128.52, 128.80,
130.14 (d, J ) 51.6 Hz), 130.46 (d, J ) 24.7 Hz), 131.48, 131.63,
131.67, 131.70, 131.74, 133.14, 133.31 (d, J ) 38.3 Hz), 133.70,
134.68 (d, J ) 37.1 Hz), 137.46, 144.37; 31P NMR (CDCl3, 121
MHz, 85%H3PO4) δ +53.28; MS (EI) m/z 528 ([M]+•, 2.13), 311
([M - 217]+, 1.47), 267 ([M - 261]+, 11.27). Anal. Calcd for
C
34H29N2PS: C, 77.27; H, 5.49; N, 5.30. Found: C, 77.52; H,
5.89; N, 5.17.
Liga n d 5 (L5): yield 51%; mp 62-64 °C; [R]25 ) -180.1
D
Rep r esen ta tive Exp er im en ta l P r oced u r e for th e Syn -
th esis of Liga n d s 1-8. To a solution of (R)-(+)-N-ethyl-1,1′-
binaphthyl-2,2′-diamine 2 (200 mg, 0.64 mmol) in THF (10.0
mL) was added dropwise n-butyllithium (1.12 mL, 1.8 mmol,
1.6 M solution in hexane) at -40 °C over 40 min, and the
reaction mixture was stirred for 1 h at the same temperature.
Then, diphenylthiophosphinic chloride (500 mg, 2.0 mmol) in
5.0 mL THF was added dropwise, and the reaction solution
was slowly allowed to warm to room temperature. After 2 h,
the THF was removed in vacuo. The residue was purified by
alumina column chromatography to give the ligand (L4) as a
colorless solid (314 mg, 93%).
(c 1.83, CHCl3); IR (KBr) ν 3350, 3054, 1619, 1595, 1507, 1438,
1422, 1338, 1219, 1153, 896, 817 cm-1; 1H NMR (CDCl3, TMS,
300 MHz) δ 2.53 (s, 6H, 2Me), 5.88 (d, J ) 9.0 Hz, NH), 7.0 (d,
J ) 8.7 Hz, 1H, Ar), 7.14-7.43 (m, 12H, ArH), 7.56-7.75 (m,
5H, ArH), 7.79-7.98 (m, 4H, ArH); 13C NMR (CDCl3, TMS,
75 MHz) δ 43.27, 118.47, 120.41 (d, J ) 4.8 Hz), 121.81, 123.92
(d, J ) 2.6 Hz), 125.75, 126.56 (d, J ) 8.3 Hz), 125.97, 128.34
(d, J ) 18.6 Hz), 128.36, 128.37 (d, J ) 24.0 Hz), 128.38 (d, J
) 47.7 Hz), 128.41, 129.67, 129.84 (d, J ) 2.8 Hz), 131.04,
131.20, 131.48, 131.52, 131.57, 131.68, 131.72, 132.99, 133.88,
134.03, 134.04 (d, J ) 46.1 Hz), 135.25, 136.59, 149.87; 31P
NMR (CDCl3, 121 MHz, 85%H3PO4) δ +51.47; MS (EI) m/z
528 ([M]+•, 46.79), 311 ([M - 217]+, 35.99), 267 ([M - 261]+,
100.00). Anal. Calcd for C34H29N2PS: C, 77.27; H, 5.49; N, 5.30.
Found: C, 77.29; H, 5.68; N, 5.12.
Liga n d 1 (L1): yield 95%; mp 180-182 °C; [R]25 ) +65.8
D
(c 0.6, CHCl3); IR (KBr) ν 3350, 1620, 1514, 1476, 1422, 927,
626 cm-1; 1H NMR (CDCl3, TMS, 300 MHz) δ 1.76 (d, J ) 13.5
Hz, 3H, Me), 1.88 (d, J ) 13.5 Hz, 3H, Me), 4.61 (d, J ) 6.6
Hz, 1H, NH), 6.96 (d, J ) 8.1 Hz, 1H, ArH), 7.13-7.40 (m,
6H, ArH), 7.80-7.99 (m, 5H, ArH); 13C NMR (CDCl3, TMS,
75 MHz) δ 24.01 (d, J ) 68.6 Hz), 24.60 (d, J ) 68.6 Hz),
110.16, 118.08, 118.97, 119.03, 122.54, 123.57, 124.25, 124.91,
126.95, 127.07, 128.09, 128.19, 128.21, 129.15, 129.97, 130.26,
133.04, 133.58, 137.62, 142.86; 31P NMR (CDCl3, 121 MHz,
85% H3PO4) δ +56.96; MS (EI) m/z 376 ([M]+•, 49.66), 284 ([M
- 92]+, 16.13), 267 ([M - 109]+, 100). Anal. Calcd for C22H21N2-
PS: C, 70.19; H, 5.62; N, 7.44. Found: C, 69.84; H, 5.82; N,
7.65.
Liga n d 6 (L6): yield 90%; mp 61-63 °C; [R]25 ) +41.3 (c
D
2.07, CHCl3); IR (KBr) ν 3020, 1625, 1600, 1521, 1750, 1423,
1030, 929, 895 cm-1; 1H NMR (CDCl3, TMS, 300 MHz) δ 1.28
(m, 6H, 2Me), 3.69 (br, 2H, NH2), 3.97-4.17 (m, 4H, 2CH2),
5.32 (d, J ) 14.1 Hz, 1H, NH), 6.91 (d, J ) 8.1 Hz, 1H, ArH),
7.12-7.37 (m, 6H, ArH), 7.80-7.96 (m, 5H, ArH); 13C NMR
(CDCl3, TMS, 75 MHz) δ 15.61 (d, J ) 8.4 Hz), 15.64 (d, J )
7.4 Hz), 63.19 (d, J ) 4.1 Hz), 63.23 (d, J ) 4.6 Hz), 110.08,
117.92, 117.96, 118.00, 118.04, 118.07, 122.44, 123.29, 124.12,
124.93, 126.84, 127.90, 128.15, 129.17, 129.75, 130.23, 132.83,
133.48, 136.31, 142.70; 31P NMR (CDCl3, 121 MHz, 85%H3-
PO4) δ +66.63; MS (EI) m/z 436 ([M]+•, 77.63), 284 ([M - 152]+,
52.04), 267 ([M - 169]+, 100). Anal. Calcd for C24H25N2O2PS:
C, 66.10; H, 5.73; N, 6.42. Found: C, 65.91; H, 6.03; N, 6.51.
Liga n d 2 (L2): yield 90%; mp 68-70 °C; [R]25 ) +30.4 (c
D
1.67, CHCl3); IR (KBr) ν 3345, 1620, 1598, 1514, 1427, 1345,
1
994, 926, 669 cm-1; H NMR (CDCl3, TMS, 300 MHz) δ 1.09
Liga n d 7 (L7): yield 97%; yellowish oil, [R]25 ) +13.7 (c
(t, J ) 7.2 Hz, 3H, Me), 1.73 (d, J ) 12.9 Hz, 3H, Me), 1.89 (d,
J ) 12.9 Hz, 3H, Me), 3.25 (q, J ) 7.2 Hz, 2H, CH2), 3.62 (br,
1H, NH), 4.61 (d, J ) 7.2 Hz, 1H, NH), 6.86 (d, J ) 9.3 Hz,
1H, ArH), 7.01-7.40 (m, 6H, ArH), 7.79-7.99 (m, 5H, ArH);
13C NMR (CDCl3, TMS, 75 MHz) δ 15.12, 23.96 (d, J ) 68.9
Hz), 24.81 (d, J ) 68.6 Hz), 38.29, 109.60, 113.68, 118.89,
118.94, 119.61, 121.91, 123.35, 124.22, 124.94, 126.89, 126.94,
127.22, 128.19, 129.13, 129.99, 130.42, 133.26, 133.66, 137.83,
144.34; 31P NMR (CDCl3, 121 MHz, 85%H3PO4) δ +56.68; MS
(EI) m/z 404 ([M]+•, 100.00), 389 ([M - 15]+, 5.87), 267 ([M -
137]+, 25.94). Anal. Calcd for C24H25N2PS: C, 71.29; H, 6.19;
N, 6.93. Found: C, 71.65; H, 6.57; N, 6.49.
D
2.57, CHCl3); IR (KBr) ν 3360, 3020, 1630, 1598, 1514, 1476,
1
1427, 1346, 1022, 964, 801 cm-1; H NMR (CDCl3, TMS, 300
MHz) δ 1.06 (t, J ) 6.9 Hz, Me), 1.28 (m, 6 H, 2Me), 3.24 (q,
J ) 6.9 Hz, CH2), 3.51 (br, 1 H, NH), 3.95-4.13 (m, 4 H, 2CH2),
5.31 (d, J ) 13.2 Hz, 1H, NH), 6.81 (d, J ) 8.4 Hz, 1H, ArH),
7.08-7.36 (m, 6 H, ArH), 7.78-7.96 (m, 5 H, ArH); 13C NMR
(CDCl3, TMS, 75 MHz) δ 15.10, 15.73 (d, J ) 7.9 Hz), 15.77
(d, J ) 7.9 Hz), 38.32, 63.27 (d, J ) 4.8 Hz), 63.30 (d, J ) 4.2
Hz), 109.70, 113.88, 118.10, 118.13, 121.91, 123.20, 124.21,
125.13, 126.80, 126.92, 127.41, 127.99, 128.23, 129.28, 129.92,
130.46, 133.22, 133.65, 136.64, 144.38; 31P NMR (CDCl3, 121
MHz, 85%H3PO4) δ +66.60; MS (EI) m/z 464 ([M]+•, 100), 311
([M - 153]+, 25.62), 267 ([M - 197]+, 70.09). Anal. Calcd for
Liga n d 3 (L3): yield 92%; mp 175-177 °C; [R]25D ) -4.0 (c
1.20, CHCl3); IR (KBr) ν 3350, 1625, 1514, 1477, 1438, 1340,
6234 J . Org. Chem., Vol. 68, No. 16, 2003

Catalytic Asymmetric Addition of Diethylzinc to N-Sulfonylimines
1
C
26H29N2O2PS: C, 67.22; H, 6.29; N, 6.03. Found: C, 67.36;
904, 806 cm-1; H NMR (CHCl3, TMS, 300 MHz) δ 0.78 (t, J
H, 6.45; N, 5.75. HRMS calcd C26H30N2O2SP (M+ + 1):
) 7.5 Hz, 3H, Me), 1.80 (m, 2H, CH2), 2.29 (s, 3H, Me), 2.38
(s, 3H, Me), 4.14 (m, 1H, CH), 4.68 (br, 1H, NH), 6.90 (d, J )
7.8 Hz, 2H, ArH), 6.98 (d, J ) 7.8 Hz, 2H, ArH), 7.14 (d, J )
8.4 Hz, 2H, ArH), 7.55 (d, J ) 8.4 Hz, 2H, ArH); 13C NMR
(CDCl3, TMS, 75 MHz) δ 10.43, 20.91, 21.34, 30.42, 59.56,
126.43, 126.95, 128.83, 129.09, 136.69, 137.66, 137.67, 142.64;
MS (EI) m/z 303 ([M]+•, 0.06), 274 ([M - 29]+, 100.00), 155
([M - 148]+, 39.05), 91 ([M - 212]+, 68.24). Anal. Calcd for
465.1756. Found: 465.1760.
Liga n d 8 (L8): yield 99%; mp 57-58 °C; [R]25D ) -149.1 (c
0.9, CHCl3); IR (KBr) ν 3350, 3020, 1619, 1598, 1517, 1475,
1424, 1378, 1216, 1045, 929, 811 cm-1; 1H NMR (CDCl3, TMS,
300 MHz) δ 1.07 (t, J ) 7.2 Hz, 3H, Me), 3.25 (q, J ) 7.2 Hz,
2H, CH2), 3.75 (br, 1 H, NH), 5.46 (d, J ) 10.8 Hz, 1H, NH),
6.98-7.49 (m, 15 H, ArH), 7.64-7.94 (m, 7H, ArH); 13C NMR
(CDCl3, TMS, 75 MHz) δ 14.77, 38.48, 113.90, 118.40 (d, J )
8.7 Hz), 119.13 (d, J ) 4.4 Hz), 122.16 (d, J ) 3.3 Hz), 124.11,
124.32 (d, J ) 84.3 Hz), 126.97 (d, J ) 5.9 Hz), 127.54, 127.63,
128.25, 128.33, 128.98 (d, J ) 71.4 Hz), 128.66, 128.68, 129.41,
129.88, 130.35, 130.96, 131.19 (d, J ) 10.3 Hz), 131.50, 131.89,
131.98, 132.02, 132.68, 133.21, 133.52, 137.66, 144.32 (d, J )
2.3 Hz); 31P NMR (CDCl3, 121 MHz, 85%H3PO4) δ +17.89; MS
(EI) m/z 512 ([M]+•, 53.62), 497 ([M - 15]+, 12.50), 295 ([M -
217]+, 92.79), 280 ([M - 232]+, 39.11). Anal. Calcd for C34H29N2-
OP: C, 79.67; H, 5.70; N, 5.47. Found: C, 79.33; H, 6.03; N,
C
17H21NO2S: C, 67.29; H, 6.98; N, 4.62. Found: C, 67.33; H,
7.06; N, 4.56. [R]25 ) -67.3 (c 2.48, CHCl3) for 86% ee;
D
Chiralpak AS, hexane/i-PrOH ) 75/25, 0.7 mL/min, tminor
20.352 min, tmajor ) 25.527 min.
)
(-)-4-Me t h y l-N -(1-m -t o ly lp r o p y l)b e n ze n e s u lfo n a -
m id e 6c (En tr y 3 in Ta ble 2): yield 141 mg, 93%; mp 82-84
°C; IR (KBr) ν 3256, 2974, 1600, 1440, 1319, 1160, 1054, 905,
1
888, 813 cm-1; H NMR (CHCl3, TMS, 300 MHz) δ 0.80 (t, J
) 7.2 Hz, 3H, Me), 1.76 (m, 2H, CH2), 2.18 (s, 3H, Me), 2.36
(s, 3H, Me), 4.14 (m, 1H, CH), 4.98 (br, 1H, NH), 6.71 (s, 1H,
ArH), 6.82 (d, J ) 7.5 Hz, 1H, ArH), 6.94 (d, J ) 7.8 Hz, 1H,
ArH), 7.05 (m, 3H, ArH), 7.53 (d, J ) 8.7 Hz, 2H, ArH); 13C
NMR (CDCl3, TMS, 75 MHz) δ 10.45, 21.08, 21.34, 30.40,
59.80, 123.57, 126.92, 127.25, 127.74, 128.09, 129.01, 137.64,
137.66, 140.44, 142.61; MS (EI) m/z 303 ([M]+•, 0.06), 274 ([M
- 29]+, 100.00), 155 ([M - 148]+, 50.67), 91 ([M - 212]+, 97.76).
Anal. Calcd for C17H21NO2S: C, 67.29; H, 6.98; N, 4.62.
5.07. HRMS calcd
512.2061.
C
34H29N2OP (M+): 512.2017. Found:
Gen er a l P r oced u r e for th e Syn th esis of th e Ra cem ic
P r od u cts Used for th e Ch ir a l HP LC An a lysis. To a
solution of N-(p-fluorobenzylidene)-p-methylbenzenesulfona-
mide 5j (139 mg, 0.5 mmol) in THF (4.0 mL) was added
dropwise ethylmagnesium bromide (1.5 mL, 1.5 mmol, 1.0 M
in THF) at 0 °C under an argon atmosphere. The reaction
mixture was stirred for 10 h at the same temperature, and
then 1.0 N HCl (5.0 mL) was added. After extraction with ethyl
acetate, the combined organic layers were dried over MgSO4.
The residue obtained upon removal of volatiles in vacuo was
purified by column chromatography on silica gel (eluent:
petroleum/ethyl acetate ) 10/1) to afford the racemic product
6j (140 mg, 91%) as a colorless solid.
Found: C, 67.26; H, 6.78; N, 4.55. [R]25 ) -60.6 (c 2.35,
CHCl3) for 86% ee; Chiralpak AD, hexane/i-PrOH ) 85/15, 0.7
mL/min, tminor ) 11.513 min, tmajor ) 12.920 min.
D
(-)-4-Meth yl-N-[1-(4-m eth oxyp h en yl)p r op yl]ben zen e-
su lfon a m id e 6d (En tr y 4 in Ta ble 2): yield 129 mg, 81%;
mp 110-112 °C; IR (KBr) ν 3290, 2964, 1615, 1511, 1465, 1456,
1322, 1250, 1173, 1160, 1003, 905, 818 cm-1; 1H NMR (CHCl3,
TMS, 300 MHz) δ 0.77 (t, J ) 7.5 Hz, 3H, Me), 1.80 (m, 2H,
CH2), 2.38 (s, 3H, Me), 3.76 (s, 3H, Me), 4.13 (m, 1H, CH),
5.02 (br, 1H, NH), 6.69 (d, J ) 11.4 Hz, 2H, ArH), 6.92 (d, J )
11.4 Hz, 2H, ArH), 7.15 (d, J ) 8.1 Hz, 2H, ArH), 7.56 (d, J )
8.1 Hz, 2H, ArH); 13C NMR (CDCl3, TMS, 75 MHz) δ 10.44,
21.32, 30.41, 55.08, 59.26, 113.50, 126.93, 127.65, 129.10,
132.80, 137.70, 142.62, 158.55; MS (EI) m/z 319 ([M]+•, 1.86),
290 ([M - 29]+, 100.00), 155 ([M - 164]+, 34.88), 91 ([M -
228]+, 63.53). Anal. Calcd for C17H21NO3S: C, 63.92; H, 6.63;
The other racemates 6a -i and 6k -o were synthesized in
the same manner as that described above.
Gen er a l P r oced u r e for th e Cu -Ca ta lyzed Asym m etr ic
Ad d ition of Dieth ylzin c to N-Su lfon ylim in e. A solution
of Cu(CH3CN)4BF4 (4.7 mg, 0.015 mmol) and ligand L2 (13.0
mg, 0.03 mmol) in dry toluene (3 mL) was stirred for 1 h at
room temperature under an argon atmosphere. N-(p-Fluo-
robenzylidene)-p-methylbenzenesulfonamide 5j (139 mg, 0.5
mmol) was added, and the solution was stirred for an ad-
ditional 10 min; then, Et2Zn (1 mL, 1 mmol, 1.0 M solution in
hexane) was added dropwise within 30 s at 0 °C. The resulting
mixture was stirred for about 8 h at the same temperature,
and then 1.0 N HCl (4.0 mL) was added. After extraction with
ethyl acetate, the combined organic layers were dried over
MgSO4. The residue obtained upon removal of volatiles in
vacuo was purified by column chromatography on silica gel
(eluent, petroleum/ethyl acetate ) 10/1) to afford the addition
product 6j (148 mg, 96%) and recovered ligand L2 (11 mg,
85%).
N, 4.39. Found: C, 63.76; H, 6.39; N, 4.29. [R]25 ) -80.1 (c
1.5, CHCl3) for 90% ee; Chiralpak AS, hexane/i-PrOH ) 75/
25, 0.7 mL/min, tminor ) 31.502 min, tmajor ) 43.851 min.
D
(-)-4-Met h yl-N-[1-(4-ch lor op h en yl)p r op yl]b en zen e-
su lfon a m id e 6e (En tr y 5 in Ta ble 2): yield 155 mg, 96%;
mp 140-142 °C; IR (KBr) ν 3246, 2963, 1600, 1496, 1432, 1318,
1166, 1093, 1049, 998, 904, 809 cm-1; 1H NMR (CHCl3, TMS,
300 MHz) δ 0.79 (t, J ) 7.2 Hz, 3H, Me), 1.75 (m, 2H, CH2),
2.39 (s, 3H, Me), 4.18 (m, 1H, CH), 4.88 (br, 1H, NH), 6.96 (d,
J ) 9.0 Hz, 2H, ArH), 7.13 (m, 4H, ArH), 7.53 (d, J ) 9.0 Hz,
2H, ArH); 13C NMR (CDCl3, TMS, 75 MHz) δ 10.37, 21.39,
30.37, 59.18, 126.93, 128.01, 128.29, 129.23, 132.84, 137.41,
139.22, 143.10. MS (EI) m/z 323 ([M]+•, 0.08), 294 ([M - 29]+,
64.46), 155 ([M - 168]+, 55.65), 91 ([M - 232]+, 100.00). Anal.
Calcd for C16H18ClNO2S: C, 59.34; H, 5.60; N, 4.33. Found:
(S)-(-)-4-Met h yl-N-(1-p h en ylp r op yl)b en zen esu lfon a -
m id e 6a (En tr y 1 in Ta ble 2): yield 135 mg, 93%; mp 108-
110 °C; IR (KBr) ν 3271, 2964, 1600, 1457, 1320, 1165, 1409,
1003, 905, 701 cm-1; 1H NMR (CHCl3, TMS, 300 MHz) δ 0.80
(t, J ) 7.5 Hz, 3H, Me), 1.79 (m, 2H, CH2), 2.38 (s, 3H, Me),
4.20 (m, 1H, CH), 4.87 (br, 1H, NH), 7.01 (m, 2H, ArH), 7.16
(m, 5H, ArH), 7.55 (d, J ) 8.4 Hz, 2H, ArH); 13C NMR (CDCl3,
TMS, 75 MHz) δ 10.41, 21.36, 30.53, 59.78, 126.50, 126.93,
127.08, 128.21, 129.15, 137.60, 140.69, 142.76; MS (EI) m/z
288 ([M - 1]+, 0.05), 260 ([M - 29]+, 89.90), 155 ([M - 134]+,
50.52), 91 ([M - 198]+, 100.00). Anal. Calcd for C16H19NO2S:
C, 66.40; H, 6.62; N, 4.82. Found: C, 66.53; H, 6.84; N, 4.78.
C, 59.38; H, 5.53; N, 4.52. [R]25 ) -52.4 (c 3.9, CHCl3) for
91% ee; Chiralpak AS, hexane/i-PrOH ) 75/25, 0.7 mL/min,
tminor ) 17.033 min, tmajor ) 26.448 min.
D
(-)-4-Met h yl-N-[1-(3-ch lor op h en yl)p r op yl]b en zen e-
su lfon a m id e 6f (En tr y 6 in Ta ble 2): yield 151 mg, 93%;
mp 71-72 °C; IR (KBr) ν 3259, 2971, 1599, 1440, 1334, 1319,
1159, 1093, 1051, 1000, 886, 782 cm-1; 1H NMR (CHCl3, TMS,
300 MHz) δ 0.81 (t, J ) 7.2 Hz, 3H, Me), 1.75 (m, 2H, CH2),
2.38 (s, 3H, Me), 4.17 (m, 1H, CH), 4.98 (br, 1H, NH), 6.87 (s,
1H, ArH), 6.95 (m, 1H, ArH), 7.11 (m, 4H, ArH), 7.52 (d, J )
8.1 Hz, 2H, ArH); 13C NMR (CDCl3, TMS, 75 MHz) δ 10.36,
21.34, 30.29, 59.30, 124.77, 126.83, 126.85, 127.09, 129.19,
129.50, 133.91, 137.26, 142.72, 143.06; MS (EI) m/z 323 ([M]+•,
0.08), 294 ([M - 29]+, 90.94), 155 ([M - 168]+, 80.14), 91 ([M
- 232]+, 100.00). Anal. Calcd for C16H18ClNO2S: C, 59.34; H,
[R]25 ) -52.2 (c 2.97, CHCl3) for 86% ee; Chiralcel OD,
D
hexane/i-PrOH ) 9/1, 0.7 mL/min, tminor ) 20.157 min, tmajor
)
25.743 min, or Chiralpak AS, hexane/i-PrOH ) 75/25, 0.7 mL/
min, tminor ) 20.342 min, tmajor ) 27.346 min.
(-)-4-Meth yl-N-(1-tolylp r op yl)ben zen esu lfon a m id e 6b
(En tr y 2, Ta ble 2): yield 144 mg, 95%, mp 86-88 °C; IR (KBr)
ν 3262, 2961, 1600, 1518, 1432, 1324, 1165, 1094, 1048, 997,
J . Org. Chem, Vol. 68, No. 16, 2003 6235

Wang and Shi
5.60; N, 4.33. Found: C, 59.44; H, 5.67; N, 4.22. [R]25D ) -57.3
(c 5.8, CHCl3) for 86% ee; Chiralpak AD, hexane/i-PrOH ) 85/
15, 0.7 mL/min, tminor ) 13.880 min, tmajor ) 15.387 min.
90 °C; IR (KBr) ν 3257, 2934, 1600, 1426, 1322, 1162, 1142,
1
1093, 1004, 934, 901, 753, 668 cm-1
; H NMR (CHCl3, TMS,
300 MHz) δ 0.84 (t, J ) 7.5 Hz, 3H, Me), 1.81 (m, 2H, CH2),
2.39 (s, 3H, Me), 4.31 (m, 1H, CH), 4.88 (br, 1H, NH), 5.90 (d,
J ) 3.3 Hz, 1H, furylH), 6.12 (dd, J ) 3.3 and 1.8 Hz, 1H,
furylH), 7.14 (d, J ) 1.8 Hz, 1H, furylH), 7.20 (d, J ) 8.1 Hz,
2H, ArH), 7.83 (d, J ) 8.1 Hz, 2H, ArH); 13C NMR (CDCl3,
TMS, 75 MHz) δ 10.10, 21.40, 28.00, 53.07, 106.82, 109.82,
126.86, 129.26, 137.61, 141.64, 142.87, 152.80; MS (EI) m/z
279 ([M]+•, 1.22), 250 ([M - 29]+, 69.37), 155 ([M - 124]+,
46.17), 124 ([M - 155]+, 33.21). Anal. Calcd for C14H17NO3S:
C, 60.19; H, 6.13; N, 5.01. Found: C, 60.02; H, 5.91; N, 4.96.
(-)-4-Met h yl-N-[1-(4-t r iflu or om et h ylp h en yl)p r op yl]-
ben zen esu lfon a m id e 6g (En tr y 7 in Ta ble 2): yield 170
mg, 95%; mp 117-119 °C; IR (KBr) ν 3266, 2973, 1599, 1439,
1327, 1159, 1120, 1086, 1068, 898, 846, 817 cm-1 1H NMR
;
(CHCl3, TMS, 300 MHz) δ 0.82 (t, J ) 7.2 Hz, 3H, Me), 1.73
(m, 2H, CH2), 2.34 (s, 3H, Me), 4.28 (m, 1H, CH), 5.21 (br, 1H,
NH), 7.07 (d, J ) 8.4 Hz, 2H, ArH), 7.12 (d, J ) 8.1 Hz, 2H,
ArH), 7.37 (d, J ) 8.4 Hz, 2H, ArH), 7.47 (d, J ) 8.4 Hz, 2H,
ArH); 13C NMR (CDCl3, TMS, 75 MHz) δ 9.94, 20.82, 30.11,
59.24, 124.99 (q, J ) 3.7 Hz), 127.54 (q, J ) 270.3 Hz), 126.86,
127.05, 129.12 (q, J ) 32.3 Hz), 129.33, 137.21, 143.11, 144.70
(q, J ) 3.7 Hz). MS (EI) m/z 357 ([M]+•, 0.04), 328 ([M - 29]+,
63.95), 155 ([M - 202]+, 75.54), 91 ([M - 265]+, 100.00). Anal.
Calcd for C17H18F3NO2S: C, 57.13; H, 5.08; N, 3.92. Found:
[R]25 ) -74.1 (c 0.68, CHCl3) for 82% ee; Chiralpak AD,
D
hexane/i-PrOH ) 80/20, 0.7 mL/min, tmajor ) 12.797 min, tminor
) 14.077 min.
(+)-4-Me t h yl-N -(1-n a p h t h a le n -1-ylp r op yl)b e n ze n e -
su lfon a m id e 6l (En tr y 12 in Ta ble 2): yield 158 mg, 93%;
mp 128-130 °C; IR (KBr) ν 3275, 2927, 1598, 1427, 1329, 1159,
1092, 989, 780 cm-1; 1H NMR (CHCl3, TMS, 300 MHz) δ 0.88
(t, J ) 7.2 Hz, 3H, Me), 1.97 (m, 2H, CH2), 2.26 (s, 3H, Me),
5.03 (m, 2H, NH and CH), 6.92 (d, J ) 8.7 Hz, 2H, ArH), 7.27
(m,2H, ArH), 7.45 (m, 4H, ArH), 7.66 (m, 1H, ArH), 7.79 (m,
1H, ArH), 7.88 (m, 1H, ArH); 13C NMR (CDCl3, TMS, 75 MHz)
δ 10.62, 21.19, 30.33, 55.46, 122.51, 123.91, 125.10, 125.30,
125.93, 126.74, 127.50, 128.58, 128.77, 130.44, 133.50, 136.66,
137.12, 142.52; MS (EI) m/z 339 ([M]+•, 6.92), 310 ([M - 29]+,
100.00), 156 ([M - 184]+, 38.41), 91 ([M - 248]+, 42.77). Anal.
Calcd for C20H21NO2S: C, 70.77; H, 6.24; N, 4.13. Found: C,
C, 57.04; H, 5.12; N, 4.00. [R]25 ) -39.7 (c 2.25, CHCl3) for
D
93% ee; Chiralcel OD, hexane/i-PrOH ) 9/1, 0.7 mL/min, tminor
) 20.350 min, tmajor ) 25.123 min.
(-)-4-Meth yl-N-[1-(4-br om oph en yl)pr opyl]ben zen esu lfo-
n a m id e 6h (En tr y 8 in Ta ble 2): yield 168 mg, 91%; mp
176-178 °C; IR (KBr) ν 3246, 2962, 1600, 1494, 1431, 1316,
1
1164, 1094, 999, 904, 808 cm-1; H NMR (CHCl3, TMS, 300
MHz) δ 0.79 (t, J ) 7.2 Hz, 3H, Me), 1.72 (m, 2H, CH2), 2.40
(s, 3H, Me), 4.17 (m, 1H, CH), 4.91 (br, 1H, NH), 6.89 (d, J )
7.8 Hz, 2H, ArH), 7.13 (d, J ) 8.4 Hz, 2H, ArH), 7.25 (d, J )
7.8 Hz, 2H, ArH), 7.50 (d, J ) 8.4 Hz, 2H, ArH); 13C NMR
(CDCl3, TMS, 75 MHz) δ 10.36, 21.44, 30.33, 59.23, 121.04,
126.95, 128.38, 129.27, 131.27, 137.37, 139.66, 143.19. MS (EI)
m/z 368 ([M]+•, 0.13), 340 ([M - 28]+, 75.84), 155 ([M - 213]+,
70.96; H, 6.14; N, 4.20. [R]25 ) +9.1 (c 1.25, CHCl3) for 88%
D
ee; Chiralpak AD, hexane/i-PrOH ) 85/15, 0.7 mL/min, tminor
) 15.647 min, tmajor ) 19.247 min.
82.97), 91 ([M - 272]+, 100.00). Anal. Calcd for C16H18
-
(-)-N-(1-P h en ylp r op yl)m eth a n esu lfon a m id e 6m (En -
tr y 13 in Ta ble 2): yield 102 mg, 96%; mp 64-65 °C; IR (KBr)
ν 3277, 2972, 2931, 1497, 1459, 1307, 1156, 1006, 901, 701
cm-1; 1H NMR (CHCl3, TMS, 300 MHz) δ 0.92 (t, J ) 7.2 Hz,
3H, Me), 1.87 (m, 2H, CH2), 2.56 (s, 3H, Me), 4.35 (m, 1H, CH),
5.04 (br, 1H, NH), 7.27-7.41 (m, 5H, ArH); 13C NMR (CDCl3,
TMS, 75 MHz) δ 10.63, 30.57, 41.54, 59.77, 126.60, 127.71,
128.73, 141.33; MS (EI) m/z 213 ([M]+•, 0.22), 184 ([M - 29]+,
100.00), 106 ([M - 107]+, 79.84), 77 ([M - 136]+, 25.20). Anal.
Calcd for C10H15NO2S: C, 56.31; H, 7.09; N, 6.57. Found: C,
BrNO2S: C, 52.18; H, 4.93; N, 3.80. Found: C, 52.19; H, 4.82;
N, 3.75. [R]25 ) -25.5 (c 1.25, CHCl3) for 92% ee; Chiralpak
D
AS, hexane/i-PrOH ) 75/25, 0.7 mL/min, tminor ) 18.44 min,
tmajor ) 29.05 min.
(-)-4-Me t h yl-N -[1-(3-flu or op h e n yl)p r op yl]b e n ze n e -
su lfon a m id e 6i (En tr y 9 in Ta ble 2): yield 144 mg, 94%;
mp 126-128 °C; IR (KBr) ν 3261, 2974, 1594, 1455, 1316, 1162,
1
1095, 1050, 1002, 907, 786 cm-1; H NMR (CHCl3, TMS, 300
MHz) δ 0.79 (t, J ) 7.5 Hz, 3H, Me), 1.74 (m, 2H, CH2), 2.36
(s, 3H, Me), 4.19 (m, 1H, CH), 4.95 (br, 1H, NH), 6.66 (m, 1H,
ArH), 6.84 (m, 2H, ArH), 7.13 (m, 3H, ArH), 7.54 (d, J ) 8.4
Hz, 2H, ArH); 13C NMR (CDCl3, TMS, 75 MHz) δ 10.34, 21.37,
30.43, 59.27 (d, J ) 1.7 Hz), 113.52 (d, J ) 1.7 Hz), 113.99 (d,
J ) 1.7 Hz), 122.25 (d, J ) 2.3 Hz), 126.95, 129.25, 129.55 (d,
J ) 8.1 Hz), 137.42, 143.11, 143.41 (d, J ) 6.3 Hz), 162.57 (d,
J ) 240.8 Hz). MS (EI) m/z 307 ([M]+•, 0.07), 278 ([M - 28]+,
81.53), 155 ([M - 151]+, 64.76), 91 ([M - 215]+, 100.00). Anal.
Calcd for C16H18FNO2S: C, 62.52; H, 5.90; N, 4.56. Found: C,
56.32; H, 6.95; N, 6.50. [R]25 ) -38.6 (c 2.63, CHCl3) for 87%
D
ee; Chiralpak AS, hexane/i-PrOH ) 75/25, 0.7 mL/min, tminor
) 12.698 min, tmajor ) 13.897 min.
(-)-2-Tr im e t h ylsilyl-N -[1-(4-ch lor op h e n yl)p r op yl]-
eth a n esu lfon a m id e 6n (En tr y 14 in Ta ble 2): yield 157 mg,
94%; mp 136-138 °C; IR (KBr) ν 3239, 2961, 1494, 1464, 1307,
1
1252, 1174, 1149, 1089, 1015, 1050, 892, 837 cm-1; H NMR
(CHCl3, TMS, 300 MHz) δ -0.10 (s, 9H, 3Me), 0.78 (dt, J )
4.2 and 14.4 Hz, 2H, CH2), 0.91 (t, J ) 7.2 Hz, 3H, Me), 1.82
(m, 2H, CH2), 2.55 (dt, J ) 4.2 and 14.4 Hz, 2H, CH2), 4.31
(m, 1H, CH), 4.71 (br, 1H, NH), 7.24 (d, J ) 8.4 Hz, 2H, ArH),
7.34 (d, J ) 8.4 Hz, 2H, ArH); 13C NMR (CDCl3, TMS, 75 MHz)
δ -2.27, 10.18, 10.72, 30.63, 49.81, 59.05, 128.14, 128.93,
133.62, 140.33; MS (EI) m/z 304 ([M - 29]+, 20.60), 166 ([M -
167]+, 5.37), 101 ([M - 232]+, 16.78), 73 ([M - 260]+, 100.00).
Anal. Calcd for C14H24ClNO2SSi: C, 50.35; H, 7.24; N, 4.19.
Found: C, 50.16; H, 7.04; N, 4.09. [R]25D ) -14.0 (c 1.7, CHCl3)
for 80% ee; Chiralpak AD, hexane/i-PrOH ) 80/20, 0.7 mL/
min, tminor ) 9.210 min, tmajor ) 10.090 min.
62.56; H, 5.91; N, 4.45. [R]25 ) -52.5 (c 4.7, CHCl3) for 85%
D
ee; Chiralcel OD, hexane/i-PrOH ) 9/1, 0.7 mL/min, tminor
19.467 min, tmajor ) 27.208 min.
)
(-)-4-Me t h yl-N -[1-(4-flu or op h e n yl)p r op yl]b e n ze n e -
su lfon a m id e 6j (En tr y 10 in Ta ble 2): yield 148 mg, 96%;
mp 116-118 °C; IR (KBr) ν 3265, 2970, 1608, 1513, 1452, 1318,
1226, 1164, 1095, 1052, 1004, 907, 808 cm-1; 1H NMR (CHCl3,
TMS, 300 MHz) δ 0.78 (t, J ) 7.2 Hz, 3H, Me), 1.75 (m, 2H,
CH2), 2.38 (s, 3H, Me), 4.18 (m, 1H, CH), 5.03 (br, 1H, NH),
6.83 (m, 2H, ArH), 6.99 (m, 2H, ArH), 7.13 (d, J ) 8.1 Hz, 2H,
ArH), 7.53 (d, J ) 8.1 Hz, 2H, ArH); 13C NMR (CDCl3, TMS,
75 MHz) δ 10.37, 21.31, 30.48, 59.11, 114.92 (d, J ) 21.3 Hz),
126.89, 128.17 (d, J ) 8.1 Hz), 129.15, 136.56 (d, J ) 2.8 Hz),
137.53, 142.93, 161.75 (d, J ) 242.7 Hz); MS (EI) m/z 307
([M]+•, 0.03), 278 ([M - 28]+, 100.00), 155 ([M - 151]+, 67.10),
91 ([M - 215]+, 88.44). Anal. Calcd for C16H18FNO2S: C, 62.52;
(-)-4-Me t h y l-N -(1-e t h y l-2-m e t h y lp r o p y l)b e n ze n e -
su lfon a m id e 6o (En tr y 15 in Ta ble 2): yield 110 mg, 86%;
mp 61-63 °C; IR (KBr) ν 3281, 2964, 1598, 1463, 1421, 1323,
1
1161, 1095, 1008, 906, 815 cm-1; H NMR (CHCl3, TMS, 300
MHz) δ 0.79 (m, 9H, 3Me), 1.27 (m, 1H, CH), 1.42 (m, 1H,
CH), 1.75 (m, 1H, CH), 2.44 (s, 3H, Me), 3.01 (m, 1H, CH),
4.35 (br, 1H, NH), 7.30 (d, J ) 9.9 Hz, 2H, ArH), 7.77 (d, J )
9.9 Hz, 2H, ArH); 13C NMR (CDCl3, TMS, 75 MHz) δ 10.05,
17.53, 18.34, 21.42, 24.36, 30.65, 60.70, 126.87, 129.38, 138.52,
142.83; MS (EI) m/z 255 ([M]+•, 0.09), 226 ([M - 29]+, 8.45),
212 ([M - 43]+, 62.14), 155 ([M - 100]+, 66.63), 91 ([M - 146]+,
H, 5.90; N, 4.56. Found: C, 62.54; H, 5.97; N, 4.52. [R]25
)
D
-39.7 (c 0.72, CHCl3) for 90% ee; Chiralpak AD, hexane/i-
PrOH ) 97/3, 1 mL/min, tmajor ) 46.880 min, tminor ) 52.800
min.
(-)-4-Met h yl-N-(1-fu r a n -2-ylp r op yl)b en zen esu lfon a -
m id e 6k (En tr y 11 in Ta ble 2): yield 132 mg, 95%; mp 88-
6236 J . Org. Chem., Vol. 68, No. 16, 2003

Catalytic Asymmetric Addition of Diethylzinc to N-Sulfonylimines
100.00). Anal. Calcd for C13H21NO2S: C, 61.14; H, 8.29; N, 5.48.
Found: C, 61.15; H, 8.48; N, 5.40. [R]25D ) -6.2 (c 3.25, CHCl3)
for 63% ee; Chiralpak AD, hexane/i-PrOH ) 85/15, 0.7 mL/
min, tmajor ) 11.683 min, tminor ) 13.250 min.
ogy, and the National Natural Science Foundation of
China for financial support (20025206 and 20272069).
Su p p or t in g In for m a t ion Ava ila b le: 13C NMR spectra
and chiral HPLC traces of the compounds shown in Tables 1
and 2. This material is available free of charge via the Internet
at http://pubs.acs.org.
Ack n ow led gm en t. We thank the State Key Project
of Basic Research (Project 973) (No. G2000048007),
Shanghai Municipal Committee of Science and Technol-
J O034269N
J . Org. Chem, Vol. 68, No. 16, 2003 6237